bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interlaboratory comparison of cholinesterase assay measurements
Authors: Marden B. Thomas , Bennett Jewel K. , Fairbrother Anne 
Published: March 2010

Abstract
Twelve wildlife toxicology laboratories participated in an interlaboratory survey of cholinesterase (ChE) assays to determine comparability of absolute ChE values and estimates of ChE inhibition from organophosphorus insecticide-dosed birds and to examine the type and consistency of methods employed by laboratories for the measurement of ChE Supernatants of brain from northern bobwhite quail (Colinus virginianus) were prepared from untreated (UT) and methyl parathion (MP)-treated birds (5 mg/kg). Assays also were conducted on a commercial preparation of acetylcholinesterase from an electric eel. All laboratories performed the ChE assays using the colorimetric assay with temperature and read times varying by laboratory. There was substantial variation in the results of ChE analyses among participating laboratories The ChE values from untreated birds ranged from 2 6 to 28.0 μmol acetylthiocholine iodide (ACTI) hydrolyzed/min/mg tissue (mean = 14.8 sd = 7 1). For the MP-treated group, ChE activity values showed a range of 1 5 to 15 3 μmol ACTI hydrolyzed/min/mg tissue (mean = 8 1, sd = 3 9) Percent inhibition values of MP-treated compared to untreated birds ranged from 37 to 51% for reported results and 37 to 49% for corrected data (activity calculated from reported absorbance data) Laboratories were most consistent in their estimates of percent inhibition of ChE activity Differences among laboratories were partially explained by differences in the methods employed for the analysis of ChE. Assay temperature and duration appeared to affect the absolute values the most However, differences in reported ChE activity values existed even when methods were very similar These results do not support the concept of using published normal ChE values from other laboratories to assess ChE inhibition in field-collected samples
Influence of ultraviolet light on the toxicity of sediments contaminated with polycyclic aromatic hydrocarbons
Authors: Ankley Gerald T , Collyard Scott A , Monson Philip D , Kosian Patricia A 
Published: March 2010

AbstractStandard 10 d toxicity tests were conducted with freshwater benthic invertebrates using sediments containing a range of concentrations of polycylic aromatic hydrocarbons (PAHs) The assays were performed both under normal laboratory fluorescent light and ultraviolet (UV) light, which mimicked wavelengths present in sunlight, at about 10% of ambient solar intensity In sediments with elevated PAH concentrations, tests conducted with UV light resulted in significantly greater mortality of Hyalella azteca (amphipods) and Lumbriculus variegatus (oligochaetes) than tests performed under otherwise comparable conditions with fluorescent light There also was increased mortality of these two species, relative to controls, when surviving organisms from the 10-d exposures to the PAH contaminated sediments were placed in clean water under UV light for 2 h These results suggest that the organisms accumulated PAHs from the test sediments, which were subsequently photoactivated by UV light to excited states more toxic than the ground state molecules The phenomenon of photoactivation has been examined for pelagic species exposed to PAHs, but not for benthic organisms exposed to sediment-associated PAHs Our results suggest that failure to consider photoactivation of PAHs by sunlight could result in sediment toxicity test methods or criteria that are underprotective of benthic organisms
Factors affecting phytoplankton species-specific differences in accumulation of 40 polychlorinated biphenyls (PCBs)
Authors: Stange Kari , Swackhamer Deborah L. 
Published: March 2010

AbstractExperiments were conducted to compare the bioaccumulation of hydrophobic compounds among different phytoplankton divisions, and to evaluate the factors that affect species-specific differences. Unialgal batch cultures of Selenastrum capricornutum, Anabaena sp., and Synedra sp. were exposed to 40 PCB congeners at 11°C for 40 d. PCBs selected for this study represented all 10 homologs, different substitution patterns, and a wide range of physical-chemical properties representative of compounds known to bioaccumulate in aquatic organisms. Congener-specific partitioning into the algal phase over time was investigated. Species differences were observed in the rate and magnitude of accumulation. For all species, a rapid association of PCBs with the algal phase was followed by a slower partitioning from the media to the algae, which continued for several days. Bioaccumulation factors (BAFs) could be predicted from Kow for PCB congeners with log Kow values &lt;6.0, whereas no such correlation was found for the more hydrophobic congeners. Normalization of BAFs to total lipid or glycolipid content reduced some of the variability between species for the less hydrophobic congeners, but not for the more hydrophobic congeners. Normalization of BAFs to the phospholipid fraction reduced species variability for the more hydrophobic congeners, supporting the hypothesis that these compounds have restricted membrane permeability.
Comparative acute toxicities of several pesticides and metals to Mysidopsis bahia and postlarval penaeus duorarum
Authors: Cripe Geraldine M. 
Published: March 2010

Abstract
Effects of toxic chemicals on estuarine and marine crustaceans are often evaluated using the mysid Mysidopsis bahia. In a literature survey of results of acute toxicity tests with estuarine crustaceans, Mysidae and Penaeidae were generally the two most sensitive families. However, neither family was consistently more sensitive (higher LC50 divided by lower LC50 &gt; 2). Mysids were 54 times more sensitive to pyrethroids than were penaeids (N = 3 studies). Yet penaeids were 36 times more sensitive (N = 4 studies) to organochlorines and 5 times more sensitive (N = 17 studies) to organophosphates than were mysids.
Acute exposures of ≤24-h-old mysids and second postlarval pink shrimp Penaeus duorarum were conducted to compare responses of these crustaceans to each other, and to values from the literature for other estuarine crustaceans. The test compounds were chloride salts of cadmium, copper, and zinc; the organophosphates diazinon, fenthion, and malathion; and several pyrethroids – cypermethrin, fenvalerate, and permethrin.
Results showed that pyrethroid toxicities to mysids and postlarval pink shrimp were similar, organophosphate toxicities were within a factor of 2.6 for both species, and mysids were 3 to 26 times more sensitive to the metals than were larval pink shrimp.
Uncertainty, complexity and post-normal science
Authors: Funtowicz Silvio O. , Ravetz Jerome R. 
Published: March 2010

Abstract
The quality of the scientific inputs to the policy process is known to be problematic. No one can claim “truth” for his results. Nor can uncertainty be banished, but good quality can be achieved by its proper management. The interaction of systems uncertainties and decision stakes can be used to provide guidance for the choice of appropriate problem-solving strategies. When either or both of these are high, then mission-oriented applied science and client-serving professional consultancy are not adequate in themselves, and an issue-driven post-normal science is necessary. Just as in cases with ethical complexities (as in biomedical science) there must be an “extended peer community,” including all stakeholders in the dialogue, for evaluating quality of scientific information for the policy process.
A decision analytic framework for environmental analysis and simulation modeling
Authors: Reckhow Kenneth H. 
Published: March 2010

Abstract
A decision analytic approach is proposed for environmental planning and analysis under scientific uncertainty. This approach begins with the creation of a planning framework that consists of all relevant objectives and attributes, along with all feasible management options; this planning framework defines the inputs and outputs for subsequent work. Decision analysis may then be used to guide the subsequent work, beginning with the selection of predictive models linking management options to objectives. Once these models are identified, decision analysis may again be used, this time to identify environmental research and monitoring priorities. The approach is illustrated with an example concerning the management of eutrophication in Lake Okeechobee, Florida. Objectives, attributes, and management options were identified for the planning framework, and a simulation model was selected for a management objective concerned with the reduction in algal blooms. This model could then be used with uncertainty analysis to define specific scientific research and monitoring needs. Finally, once scientific analysis is complete, decision analysis can be used as the framework for decision making.
Risk-based environmental remediation: Decision framework and role of uncertainty
Authors: Dakins Maxine E. , Toll John E. , Small Mitchell J. 
Published: March 2010

Abstract
A methodology for incorporating uncertainty in model predictions into a risk-based decision for environmental remediation is illustrated, considering polychlorinated biphenyl (PCB) sediment contamination and uptake by winter flounder in New Bedford Harbor, Massachusetts. Sensitivity and uncertainty analyses are conducted for a model that predicts the sediment remediation volume required to meet a biota tissue concentration criterion. These evaluations help to identify the variables that most significantly contribute to uncertainty in the model prediction and allow for calculations of the expected value of including uncertainty (EVIU) and the expected value of perfect information (EVPI) for the remediation decision. The EVIU is the difference between the expected loss of a management decision based solely on a deterministic analysis and the expected loss of the optimal management decision that considers uncertainty. For the illustrative application to New Bedford Harbor, the expected loss avoided from performing an uncertainty analysis and using the resulting information to make the optimal management decision is approximately $20 million. The EVPI, the expected decrease in loss that can be achieved by having all uncertainty eliminated, is approximately $16 million.
Application of multivariate techniques to endpoint determination, selection and evaluation in ecological risk assessment
Authors: Landis Wayne G. , Matthews Robin A. , Matthews Geoffrey B. , Sergeant Anne 
Published: March 2010

Abstract
Ecological risk assessment has evolved so that the interaction among the components is now an implicit assumption. Unlike single species-based risk assessments, it is often crucial in environmental or ecological risk assessments to be able to describe a system with many interacting components. In addition, some quantifiable description of how different biological communities respond upon the addition of a toxicant or some other stressor is required to adequately describe risk at the ecosystem level. Three methods have been applied at this level: the mean strain measurement used by K. Kersting, the state-space analysis pioneered by A.R. Johnson, and the nonmetric clustering developed by G. Matthews for ecological data sets and for analysis of standardized aquatic microcosm data. Each method has direct application to the description of an affected ecosystem with-out reliance upon a single specific and perhaps misleading endpoint. Each also can assign distance or probability measures in order to compare the control to treatment groups. Nonmetric clustering (NMC) has the advantage of not attempting to combine different types of scales or metrics during the multivariate analysis and is robust against interference by random variables. Applications of these methodologies into an ecological risk assessment should have the benefit of combining large interactive data sets into distinct measures to be used as a measure of risk and as a test of the prediction of risk. The primary impact of these methods may be in the selection and interpretation of assessment and measurement endpoints. Much recent debate in toxicological studies has focused on appropriate measurement endpoints for tests. Nonmetric clustering and other multivariate techniques should aid in the selection of these endpoints in ways meaningful at the ecosystem level. We suggest that the search for assessment and measurement endpoints be left to the appropriate multivariate computation algorithms in the case of multispecies situations. Application of these methods in the verification and validation process of risk assessment will serve to check the selection of endpoints during modeling exercises and to improve the presentation of assessment criteria.
Ecological risk assessment for river sediments contaminated by creosote
Authors: Pastorok Robert A. , Sampson Jennifer R. , Jacobson Michael A. , Peek Daniel C. 
Published: March 2010

Abstract
An ecological risk assessment was conducted for sediments of the lower Willamette River near a wood-treatment (creosote) facility. Both surface and subsurface sediments near the facility are contaminated by polycyclic aromatic hydrocarbons (PAHs). Limited contamination of sediments by dioxins/furans, chlorinated phenols, and arsenic was also observed. Sediment bioassays based on amphipod (Hyalella azteca) mortality and Microtox® (Photobacterium phosphoreum) bioluminescence showed toxicity within approximately 300 ft of the shoreline, with a highly toxic area (i.e., possible acute lethal effects in sedentary benthic species) near a dock used for creosote off-loading. The relatively low concentrations of contaminants measured in crayfish muscle tissue and the absence of serious lesions in livers of large-scale sucker collected near the site suggest that excess risk to mobile species from chronic contamination is low. Cursory observations indicate that acute toxic effects on crayfish may be associated with creosote seeps. There is no evidence of adverse biological effects throughout most of the main channel of the river. Evaluation of sediment chemistry data for PAHs relative to available sediment-quality criteria proposed by the U.S. Environmental Protection Agency supports this conclusion.
Physiological changes and tissue metal accumulation in rainbow trout exposed to foodborne and waterborne metals
Authors: Farag Aïda M. , Boese Connie J. , Bergman Harold L. , Woodward D.F. 
Published: March 2010

Abstract
Sublethal physiological effects and metal residue accumulation in tissues were measured in adult and juvenile rainbow trout fed a metal-contaminated diet and/or exposed to waterborne metals for 21 d. The consumption of metal-contaminated invertebrates from the Clark Fork River, Montana, significantly affected scale loss and metal accumulation in gut tissue of adult trout. Survival, scale loss, and metal accumulation in gill and kidney tissue were affected by exposure to a waterborne mixture of Cd, Cu, and Pb at twice the acceptable levels and Zn at the maximum acceptable level established by the U.S. Environmental Protection Agency for protection of aquatic wildlife. A combination of dietary and waterborne metals also caused lipid peroxidation in the kidney of adult fish and decreased whole-body potassium of juvenile trout. In general, metal accumulation in tissues was higher in gill and kidney with waterborne exposures and was higher in stomach and pyloric caeca with dietary exposure. And metal concentrations in juvenile whole-body tissues accumulated significantly with a combination of waterborne and dietary metals. Although some physiological changes were noted (scale loss, lipid peroxidation of kidney), an exposure time longer than 21 d is probably needed to observe more extensive physiological changes. Regardless, results from this study suggest that a full assessment of metal exposure to fish populations in natural systems must include evaluation of dietary as well as waterborne metal contamination.
A mechanistic structure-activity relationship for hepatic polysubstrate monooxygenase
Authors: Hollebone B.R. , Davis D. , Michelin N. , Purdy D. , Brownlee L.J. 
Published: March 2010

AbstractThe polysubstrate monooxygenase (PSMO) system response to hydrophobic xenobiotics is both intensive in oxidizing power and extensive in enzyme quantity. Under in vitro pseudo-first-order rate conditions the extensive properties become irrelevant, and the intensive rate-determining step depends on chemical structure. Xenobiotics react with PSMO either as inducers (adaptation domain) or as substrates (reaction domain) to produce “intended” hydroxylation, but “accidental” oxidations may also occur. Both the induction of intensive oxidizing power in the adaptation domain and the efficiency of reaction in the reaction domain depend on the strength of the weakest CH bond in the xenobiotic, consistent with either a free radical or an ionic SE2 reaction process. Only the ionic SE2 mechanism is sensitive to the electrical charge on the carbon atom of the weakest CH bond. In this study systematic “treatment” of simple hydrocarbon structures by adjacent polarizing heteroatoms N, Cl, and O inhibited substrate metabolism in direct proportion to their polarizing power. With this evidence of preferential SE2 behaviour, a QSAR is proposed that allows prediction of four types of disease end points. These arise as combination of conditions of intended or accidental oxidations combined with release of metabolites into cytosolic or lipid media.
Chemical characterization and toxicological testing of windrow composts from explosives-contaminated sediments
Authors: Griest W.H. , Tyndall R.L. , Stewart A.J. , Caton J.E. , Vass A.A. , Ho C.-H. , Caldwell W.M. 
Published: March 2010

Abstract
Aerated and nonaerated windrow composts of explosives-contaminated sediments at the Umatilla Army Depot Activity (UMDA, Hermiston, OR) were characterized chemically and toxicologically as a function of composting time. The concentrations of explosives in organic solvent extracts of the composts and in the aqueous leachates of the composts, the bacterial mutagenicity of organic solvent extracts from the composts, and the toxicity of aqueous leachates from the composts to Ceriodaphnia dubia all declined rapidly (&lt;15 d) with composting. The nonaerated windrow method of composting was slightly more efficient than was the aerated windrow method for reducing explosives concentrations in the composts (TNT, 99.9%; RDX, &gt;99.7%; HMX, 98.5%) and in their leachates (&gt;99.6%, &gt;98.8%, and &gt;97.5%, respectively). Extractable mutagenicity declined 99.7 and 97.9%, respectively, for strains TA-98 and TA-100 (without S-9 metabolic activation) in the nonaerated compost. The two types (aerated and nonaerated) of windrow composts had about the same level of efficiency in lowering leachable toxicity (by 92% and 87%, based on reductions in C. dubia survival and fecundity, respectively). Thus, windrow composting appeared to be at least as effective as static-pile and mechanically stirred composting evaluated previously. Windrow composting also appeared to be somewhat more effective for HMX transformation.
Life-cycle changes and zinc shortage in cadmium-tolerant midges, chironomus riparius (diptera), reared in the absence of cadmium
Authors: Postma Jaap F. , Mol Sandra , Larsen Hanne , Admiraal Wim 
Published: March 2010

Abstract
Adaptation to selected metals is known to modify life-cycle characteristics of some invertebrates and can modify the response to other metals. The reverse process, i.e., adaptation to nonpolluted conditions in a metal-tolerant strain, was studied here for a cadmium-tolerant population of the midge Chironomus riparius to detect whether this “backward” adaptation followed the same lines. It appeared that cadmium-tolerant populations, reared in the absence of cadmium, continued to suffer from high mortality rates and lowered larval growth rates and reproductive success. Also, some cadmium-tolerant populations accumulated more zinc than did nontolerant populations. Successive experiments in which both cadmium-tolerant and nontolerant populations were exposed to zinc indicated that the reduced growth rate and reproduction were a direct consequence of zinc shortage in tolerant midges reared in the absence of cadmium. Mortality among cadmium-tolerant midges was, however, not lowered by zinc exposure and, judged by their high mortality rates, these midges were even more sensitive to zinc than were nontolerant chironomids. It was concluded that cadmium-tolerant chironomid populations recovering from prolonged exposure are affected by an increased need for zinc as well as by an increased mortality rate as a direct consequence of the earlier adaptation process.
Influence of environmental factors on the physiological condition and hepatic ethoxyresorufin o-deethylase (erod) activity of gizzard shad (Dorosoma cepedianum)
Authors: Levine Steven L , Oris James T , Wissing Thomas E. 
Published: March 2010

Abstract
Field and laboratory experiments were conducted to monitor seasonal cytochrome P4501A monooxygenase (MO) activity (measured as ethoxyresorufin O deethylase (EROD) activity) in gizzard shad (Dorosoma cepedianum) Basal EROD activity declined in midsummer but returned to postspawning spring levels by late summer Seasonal variation in basal EROD activity corresponded with changes in liver somatic index, condition factor, and percent body lipid, indicating that seasonal variation in basal field EROD activity may result from changing physiological condition Benzo[a]pyrene induction experiments demonstrated that, although the level of EROD activity changed seasonally, the magnitude of induction relative to corn oil injected controls remained the same Kinetic studies indicated monthly changes in apparent Vmax but no change in apparent Km Taken together, these results suggest that seasonal changes in EROD activity reflect changes in hepatic P4501A protein concentration This study has demonstrated that it can be inappropriate to interpret EROD activity from a suspect site without first understanding how seasonal field conditions influence P4501A activity
Effects of embryonic exposure to methylmercury on larval prey-capture ability in the mummichog, fundulus heteroclitus
Authors: Weis Judith S. , Weis Peddrick 
Published: March 2010

Abstract
Embryos of the mummichog (Fundulus heteroclitus) were exposed to 2, 5, or 10 m̈g/L methylmercury (meHg) throughout development; these are concentrations below those which cause teratological effects in this species. After hatching, larvae were maintained in clean seawater and tested for prey-capture ability, using Artemia salina nauplii. Larvae that had been exposed to 10 m̈g/L methylmercury (and in two out of three trials, 5 m̈g/L) initially exhibited slower prey-capture ability than did the other groups. This is an indication of a subtle functional impairment due to the toxicant (“behavioral teratology”). However, the effect was transitory, and by about 1 week after hatching the prey capture of these larvae equalled that of the controls and the other treated groups. Growth of these larvae was also comparable to that of controls. The exposure may have caused retardation of neurological development, which was subsequently compensated for, and therefore no long-lasting effects were produced. In the field, however, embryos exposed to toxicants would probably continue to be exposed as larvae, and might not have the opportunity to recover from the deleterious effects, but rather might have them augmented.