bluuebunny/crossref_metadata_2025_split huggingface dataset:
Variability of community metrics: Detecting changes in structure and function
Authors: Pratt J. R. , Bowers N. J. 
Published: March 2010

Abstract
Increased environmental realism in toxicity testing has been advocated to better predict ecological effects of toxic chemicals, and several aquatic microcosm bioassays have been developed that use both natural and synthetic organism assemblages. Additionally, greater emphasis is being placed on community changes as evidence of adverse effects on aquatic ecosystems. The ability to infer structural or functional changes in stressed vs. unstressed communities is linked to statistical power that arises from the combination of experimental design and the underlying variability in chosen metrics. We evaluated several community response variables (metrics) in aquatic laboratory microcosm experiments and field studies to estimate metric variability. Variability of community metrics under laboratory conditions was similar to that observed in the field. Power curves were constructed to estimate the detectability of significant responses with different experimental designs. Using the median C. V. for each measured response, we estimated the minimum detectable distance for power of 0.8 (β = 0.2) and α = 0.05 for each response. Community metrics with C.V.s &lt;30% allow detection of differences between means of 20 to 60%, using as few as three replicates. Structural metrics such as species richness and standing crop are expected to prove more useful in detecting community and ecosystem changes. Process rates are affected by material supplies that may not change under stress.
Evaluation of community and ecosystem monitoring parameters at a high-elevation, rocky mountain study site
Authors: Bruns D. A. , Wiersma G. B. , Minshall G. W. 
Published: March 2010

Abstract
A multimedia systems approach was used to field test wilderness monitoring guidelines (U.S. Forest Service) at a high elevation site in western Wyoming. Five evaluation criteria having a primary emphasis on an ecosystem conceptual framework were applied to selected ecological parameters (terrestrial and aquatic) that were ranked on a relative scoring basis. The ecosystem conceptual criterion was based on the general attributes of the subalpine system, the nature of the potential environmental problem (acidic deposition), and ecological resources at risk. The other criteria were data variability, uncertainty, usability of methods, and cost-effectiveness. Data on sulfate deposition and buffering capacity of soils and surface waters relative to an elevational gradient supported the notion of greater risk to ecological resources in the subalpine environment. Within this ecosystem perspective, litter decay and taxonomic richness of lotic macroinvertebrates had the highest rating, followed by lotic functional feeding groups and lignin-to-nitrogen ratios. A biotic index for stream macroinvertebrates received the lowest rating on an ecosystem conceptual basis and also scored low on the uncertainty and cost-effectiveness criteria; however, suggestions were made for future improvement. Most parameters were similar in regard to variability and usability, except for functional groups, which exhibited greater data variability.
An evaluation of a genotoxicity assay with liver s9 for activation and luminescent bacteria for detection
Authors: Thomas Johnson B. 
Published: March 2010

Abstract
A new short-term in vitro genotoxicity assay with marine bioluminescent bacteria was evaluated for sensitivity and cost. Known under the trade name of Mutatox™, this assay is a simple and rapid screening tool that detects DNA-damaging substances (genotoxins) by measuring light output from an isolated dark mutant strain of the luminescent bacterium Photobacterium phosphoreum. A positive response indicates the ability of the test chemical to restore the luminescent state in the dark mutant strain; the degree of light increase indicates the relative genotoxicity of the sample. In this study, the Mutatox assay with rat hepatic fractions (S9) as an exogenous metabolic activation system detected genotoxic activity with known progenotoxins: 2-acetamidofluorene, aflatoxin B1, 2-aminoanthracene, 2-aminofluorene, 2-aminonaphthalene, benzo[a]pyrene, 3-methyl-cholanthrene, and pyrene. Each chemical clearly demonstrated a dose response between 5.0 and 0.6 μg per tube. Known nongenotoxic controls carbofuran, di-2-ethylhexyl phthalate, malathion, simazine, and permethrin showed no genotoxic responses. The optimum assay conditions were determined to be rat S9 concentration of 0.4 mg/ml, preincubation at 37°C for 30 min, and 18 h incubation at 23°C. Genotoxicity data were obtained in &lt;24 h. The Mutatox assay compared favorably in sensitivity with the Ames test; it was easier and more rapid to perform and, as a result, cost less. The sensitivity, specificity, and predictive value suggested that the Mutatox assay could be a valuable screening tool to monitor complex environmental samples for genotoxins.
The use of freshwater and saltwater animals to distinguish between the toxic effects of salinity and contaminants in irrigation drain water
Authors: Ingersoll C. G. , Dwyer F. J. , Burch S. A. , Nelson M. K. , Buckler D. R. , Hunn J. B. 
Published: March 2010

Abstract
Irrigation drain waters entering Stillwater Wildlife Management Area (SWMA) in south-western Nevada contain elevated levels of salinity and several inorganic contaminants (As, B, Cu, Li, Mo, and Sr). Mortalities of fish and waterfowl at the management area are believed to be associated with the poor water quality of the drains. The objective of the present study was to use fresh-water and saltwater animals to distinguish between the toxic effects of salinity and contaminants in effluent samples collected from irrigation drain waters. Static acute effluent tests were conducted with water collected from four sites at SWMA. Animals acclimated or cultured in fresh water (fathead minnows, Pimephales promelas; amphipods, Hyalella azteca; cladocerans, Daphnia magna) and salt water (striped bass, Morone saxatilis; amphipods, Hyalella azteca; and cladocerans, Daphnia magna) were used to separate toxic effects of salinity from the effects of inorganic contaminants in the drain water. One drain water (TJ drain, salinity 19 parts per thousand (grams per liter), osmolality 503 mmol/kg, hardness 3,780 mg/L as CaCO3) was toxic only to freshwater animals and saltwater cultured daphnids; water from a receiving pond (Pintail Bay, salinity 23 g/L, osmolality 542 mmol/kg, hardness 830 mg/L as CaCO3) was toxic to both freshwater and saltwater animals. Acute tests conducted with reconstituted waters representative of the Pintail Bay sample indicated that atypical ion ratios were toxic to striped bass and amphipods, even without the addition of inorganic contaminants. However, the addition of inorganic contaminants representative of the Pintail Bay sample increased the toxicity of this reconstituted water. These findings indicate that the toxicity of the TJ drain sample was related mainly to elevated salinity and that the toxicity of the Pintail Bay sample was a function of inorganic contamination and atypical ion ratios in combination with elevated salinity.
Influence of the addition of cerophyl® on theSelenastrum capricornutumdiet of the cladoceranCeriodaphnia dubia
Authors: Knight John T. , Waller William T. 
Published: March 2010

AbstractA study of the green alga Selenastrum capricornutum and Cerophyl® was conducted to characterize the mixture as food for Ceriodaphnia dubia. The addition of an aqueous extract of Cerophyl to Selenastrum capricornutum resulted in consistently greater survival, growth, and productivity of Ceriodaphnia dubia cultured and tested in reconstituted hard water. Several supplemental foods, including yeast-Cerophyl-Trout Chow® (YCT), were tested with, or in addition to, Selenastrum capricornutum. Analysis of the protein, carbohydrate, and lipid content of the algae-plus-Cerophyl feeding suspension indicated that the addition of the aqueous extract of Cerophyl increased the protein concentration of the feeding suspension 30% and the carbohydrate concentration 50%. The amount of lipid contained in the Cerophyl extract was less than the detection limit of the method used for analysis. Treatment of the aqueous extract of Cerophyl for the removal of the protein and lipid components of the Cerophyl had no effect on the growth and productivity of Ceriodaphnia dubia when compared to those of the organisms fed an unaltered mixture of algae plus Cerophyl. The bacteria associated with the Selenastrum capricornutum cultures, the algae-plus-Cerophyl feeding suspension, the Ceriodaphnia dubia mass cultures, and the individual beakers in which isolated Ceriodaphnia dubia was tested were enumerated. The bacteria associated with the algae-Cerophyl feeding suspension were shown to play a role in the diet of Ceriodaphnia dubia during the first 4 to 5 d of 7-day tests. However, substituting bacteria for Cerophyl in the algal feeding suspension fed to Ceriodaphnia dubia did not result in the same level of survival, growth, and productivity.
Factors affecting the bioconcentration of hexachlorocyclohexanes in early life stages of Oncorhynchus mykiss
Authors: Viganò L. , Galassi S. , Gatto M. 
Published: March 2010

Abstract
A commercial mixture of α-, β-, γ-, and δ-hexachlorocyclohexane (-HCH) isomers has been tested for bioconcentration on early life stages of Oncorhynchus mykiss. Experimental results were elaborated by means of BIOCON, an interactive program for personal computers that provides bioconcentration factors (BCFs) and kinetic uptake and depuration coefficients as well as their standard deviations. The comparisons performed on a statistical basis evidenced few differences among the bioconcentration capability of larval stages, contrary to what was observed in previous studies with other chemicals. In the early juvenile stage, α- and δ-HCH are characterized by higher BCFs than the γ-isomer. The role of lipids is also investigated. The total lipid content seems to play a major role in influencing bioaccumulation parameters but cannot thoroughly explain BCF variability, which must be ascribed to other factors such as life stage and lipid composition.
Effect of organic carbon on the uptake and toxicity of quaternary ammonium compounds to the fathead minnow, Pimephales promelas
Authors: Versteeg Donald J. , Shorter Shirley J 
Published: March 2010

Abstract
The effect of dissolved organic, carbon on the uptake and toxicity of quaternary ammonium compounds was investigated with the fathead minnow, Pinephales promelas Aldrich humic acid (HA) reduced the toxicity of dioctadccyl dimethyl ammonium chloride (DODMAC) and monotallow trimethyl ammonium chloride (C1c 1gTMAC) but had no effect on the toxicity of tetradecyl trimethyl ammonium chloride (CgTMAC) dodecyl trimethyl ammonium chloride (C12, TMAC) or of octyl trimethyl ammonium chloride (CbTMAC) Aldrich HA also reduced the uptake rate constant of DODMAC and C16 12TMAC For DODMAC, the reduction in toxicity observed by Aldrich HA was similar to those observed with Suwannee River and Nordic Aquatic HAs and organic carbon from two river waters For C1c 1gTMAC Suwannee River and Nordic Aquatic HAs and river water organic carbon caused a significant amelioration of toxicity This amchoration of toxicity was quantitatively less than predicted based on Aldrich HA
An equilibrium model of organic chemical accumulation in aquatic food webs with sediment interaction
Authors: Thomann Robert V. , Connolly John P. , Parkerton Thomas F. 
Published: March 2010

Abstract
A five-compartment steady-state food-web model is constructed that includes a benthic invertebrate compartment Four exposure routes are considered in the description of accumulation by benthic animals ingestion of particulate contaminants associated with (a) sediment organic carbon and (b) overlying phytoplankton and ventilation of free dissolved contaminant in (c) interstitial and (d) overlying water Normalization of organism lipid-based chemical concentration to sediment organic carbon (the biota sediment factor, BSF) or to overlying water concentration (the bioaccumulation factor, BAF) indicates the significance of the sediment/overlying water partition coefficient for systems that have a benthic component The impact of the benthic component on a forage fish is related directly to this partitioning Application of the model to an amphipod-scul pin web for Lake Ontario indicates (a) amphipod water exposure is a combination of interstitial and overlying water concentrations, (b) amphipod feeding appears to be a combination of overlying phy toplankton and sediment organic carbon, (c) amphipod and sculpin chemical assimilation efficiency appears to be a complicated function of octanol-water partition coefficient, (d) observed BAF for amphipod and sculpin is about one order of magnitude higher than log Kow in the range 5 5 to 7 0 and is calculated to be due almost entirely to food-web transfer from the sediment, as opposed to uptake from the water route
Uncertainty and sediment quality assessments: II. Effects of correlations between contaminants on the interpretation of apparent effects threshold data
Authors: Alden Raymond W. , Rule Joseph H. 
Published: March 2010

Abstract
The apparent effects threshold (AET) is an approach being considered for the establishment of sediment quality criteria The AET is the empirically determined concentration of a contaminant in sediments above which adverse biological effects have been observed consistently However, previous investigators have suggested that correlation among contaminants may limit the applicability of the AET approach The present study employed empirically based simulations to examine the effects of correlation among contaminants on the validity of AETs as ecologically de fensible sediment quality criteria The simulations indicated that moderately high correlations (r &gt; 0 6) between contaminants produced a high probability of setting invalid AETs Slightly higher correlations (r &gt; 0 7) produced invalid AETs that could not be detected as being “false,” even with large sampling efforts (n = 300) False AETs also were observed to be frequently encountered for more modest sampling regimes (n = 50) when correlations among contaminants were high (r &gt; 0 7)
It is clear that AETs can serve as indicators/surrogates for toxicants in sediments of the region in which they are established However, considering the confounding effects of correlations between contaminants, both measured and unmeasured, it is recommended that regulatory sediment quality assessments be based on site-specific toxicological investigations rather than generic AET based criteria or standards Any AET based criteria should be considered “first cut” levels of concern for identifying areas that display heavy sediment contaminant loads Regulatory actions based on AET criteria should be implemented only if these values have been validated by independent toxicological investigations
Bioindicators of contaminant exposure and sublethal effects: Studies with benthic fish in puget sound, Washington
Authors: Stein John E. , Collier Tracy K. , Reichert William L. , Casillas Edmundo , Hom Tom , Varanasi Usha 
Published: March 2010

Abstract
A suite of chemical and biochemical variables responsive to contaminant exposure was measured in three species of benthic flatfish (English sole, Parophrys vetulus, rock sole, Lepidopsetta bilineata, and starry flounder, Platichthys stellatus) sampled from up to five sites in Puget Sound, Washington, to assess the sensitivity of the parameters to differences in levels of contaminant exposure The examined indexes were levels of (a) polychlorinated biphenyls (PCBs) in liver, (b) fluorescent aromatic compounds in bile, (c) hepatic aryl hydrocarbon hydroxylase and ethoxy-resorufin O deethylase, (d) total hepatic GSH and (e) hydrophobic DNA xenobiotic adducts in liver as measured by 32P postlabeling The sediment concentrations of PCBs and the sum of selected polycyclic aromatic hydrocarbons at the sampling sites ranged from 21 to 570 and 21 to 5,300 ng/g wet weight sediment, respectively The results showed (a) that all the examined indexes could discriminate among sites exhibiting different degrees of chemical contamination, (b) that species differed in the range of response of most of the measured indexes, and (c) that the use of the indexes in concert appeared to enhance the assessment of contaminant exposure and sublethal effects
Genotoxicity of 2,4,5-trichlorophenoxyacetic acid biodegradation products in the Salmonella reversion and lambda prophage-induction bioassays
Authors: George S. Elizabeth , Whitehouse Douglas A. , Claxton Larry D. 
Published: March 2010

Abstract
Pseudomonas cepacia strain AC1100 has been isolated and reported to utilize 2,4,5-trichlorophenoxyacetic acid (2,4,5 T) as sole carbon and energy source Metabolites from the 2,4,5-T degradation pathway were tested for their mutagenicity in the Salmonella reversion bioassay and genotoxicity in the prophage-induction bioassay The parental compound (2,4,5-T) and three reported metabolites (2,4,5 trichlorophenol, 2,5-dichlorohydroquinone, and 2-chlorosuccinate) were negative with and without metabolic activation in Salmonella typhimurium strains TA98, TA100, TA102, and TA104 Conversely, 2,4,5-T and 2,4,5 trichlorophenol were positive in the prophage-induction bioassay with added S9 2,4,5-Trichlorophenol was approximately 100 fold more genotoxic than 2,4,5-T 2,5-Dichlorohydroquinone was a weak direct-acting genotoxicant in this assay In order to determine if strain AC1100 eliminated genotoxicity, 2,4,5 T medium was inoculated and the genotoxicity and the amount of 2,4,5-T remaining were examined over the growth period As cell numbers increased, the percentage of 2,4,5-T remaining in the medium decreased This decrease coincided with a decrease in genotoxicity in the prophage-induction bioassay No mutagenic response was observed in the Salmonella reversion assay
Performance characteristics of effluent toxicity tests: Summarization and evaluation of data
Authors: Parkhurst Benjamin R. , Warren-Hicks William , Noel Lynn E. 
Published: March 2010

Abstract
With increased use of toxicity testing for monitoring effluent toxicity, it is important to evaluate the precision of effluent toxicity tests To address this need, we identified, compiled, summarized, and evaluated published and unpublished data from intralaboratory and interlaboratory studies on the variability of acute and chronic effluent toxicity tests for single chemicals and effluents A total of 23 published and unpublished reports were identified The most extensive data on test variability are available for acute tests with Daphnia spp, Pimephales promelas, and Mysidopsis bahia and chronic tests with Pimephales promelas, Ceriodaphnia dubia, and Cyprinodon variegatus All other tests have considerably fewer data Data on which to evaluate the variability of toxicity tests produced by the most current U S Environmental Protection Agency methods are not extensive Mean C V s for intralaboratory studies (7-33%) were smaller than those for interlaboratory studies (34-46%) However, mean intra and interlaboratory C V s for chronic tests (7-38%) were generally equal to or smaller than those from acute tests (17-46%) Also, C V s from single chemical tests (32-46%) were generally larger than those from effluent tests (7-34%)
Lead, cadmium, selenium and mercury in seabird feathers from the tropical mid-pacific
Authors: Burger Joanna , Schreiber Elizabeth Anne E. , Gochfeld Michael 
Published: March 2010

Abstract
We compared the levels of lead, cadmium, selenium, and mercury in adults of several species of seabirds nesting on Manana Island off Oahu, Hawaii, and on Sand and East islands, Johnston Atoll, in 1990 Examined species included sooty tern (Sterna fuscata), brown noddy (Anous stolidus), wedge-tailed shearwater (Puffinus pacificus), brown booby (Sula leucogaster), and redfooted booby (S sula) For both locations and all metals we found significant interspecific differences There were some consistent patterns within sites selenium levels were two to three times higher in brown noddies compared to the other species, mercury levels in wedge tailed shearwaters were two to five times higher than those in sooty terns or brown noddies, but were similar to levels in boobies Cadmium levels were generally low The significant interspecific differences in metal levels indicate that the levels for some species may not be background levels Hawaiian sooty terns had higher lead levels than those from Johnston, but the noddies had higher selenium and mercury levels and shearwaters had higher lead and mercury levels on Johnston Sooty terns and brown nod dies had higher lead levels in Hawaii and Johnston Atoll than in Australia or the Caribbean
Effects of food and water quality on culturing of Ceriodaphnia dubia
Authors: Cooney J.D.C. , Pollock T.L. , Degraeve G.M. , Moore E.L. , Palmer W.D. 
Published: March 2010

Abstract
The U.S. Environmental Protection Agency (EPA) has developed a 7-d test to evaluate effluent effects on Ceriodaphnia dubia survival and reproduction. Several foods have been used to culture and test Ceriodaphnia dubia in both laboratory waters and surface waters with variable results. This study's objective was to evaluate effects of eight diets on survival and reproduction of Ceriodaphnia dubia in hard reconstituted water (HRW); HRW was used alone or supplemented with bacteria or selenium to determine whether their addition would improve survival and reproduction. Diets consisted of yeast, trout food (TF), yeast/trout food/Cerophylc̊ (YTC), Selenastrum capricornutum, Ankistrodesmus convolutus, Chlamydomonas reinhardii, Selenastrum capricornutum plus TF, and Selenastrum capricornutum plus YTC. Screening tests in HRW with each diet (at several levels) were first used to rank diets; diets with high survival (®80% at 14 d) and reproduction (®3 young per female per reproductive day) were further evaluated in multigeneration feeding tests. Finally, diets yielding high survival and reproduction in HRW were evaluated in surface and well water to verify adequacy in waters of differing composition and quality. Yeast, trout food, YTC, Selenastrum capricornutum, Ankistrodesmus convolutus, or Chlamydomonas reinhardii used alone were unacceptable for long-term culturing in HRW under test conditions used in this project. Success of the EPA's recommended food, YTC, was dependent on water, with worst results in HRW. The addition of selenium and bacteria to the HRW did not consistently improve either survival or reproduction of Ceriodaphnia dubia in the diet tests. Some of the diet test results were confounded by the use of batches of HRW that periodically contained some unidentified components that were toxic to Ceriodaphnia dubia. Both Selenastrum capricornutum plus TF and Selenastrum capricornutum plus YTC were acceptable for culturing with high survival and reproduction.
Infrared spectroscopy-based property-reactivity correlations for predicting environmental fate of organic chemicals
Authors: Collette Timothy W. 
Published: March 2010

Abstract
A conventional structure-activity relationship (SAR) has been established between the alkaline hydrolysis rate constants (koh) of 12 alkyl and aryl formates and acetates and the linear combination of the frequencies of the C=o and C—o infrared (IR) absorbance peaks. The inability of this relationship to predict koh values for more structurally diverse carboxylic acid esters led to the development of a prototype of a prediction system that employs multiple linear regression analysis, using points from the Fourier transforms (FTs) of IR spectra. Conventional SARs have also been observed between single IR peak parameters and the microbial degradation rate constants of amides (C=O peak frequencies), 2,4-dichlorophenoxyacetate esters (CH peak intensities), phenols (OH peak frequencies), and anilines (NH stretching peak intensities). These observations indicate the feasibility of extending the FT-based prediction system to microbial degradation when reliable rates are available for additional compounds.