bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluating reptile exposure to cholinesterase-inhibiting agrochemicals by serum butyrylcholinesterase activity
Authors: Sanchez-Hernandez Juan C. 
Published: March 2010

Abstract
Blood samples from lizards (Gallotia galloti) collected from two agricultural areas (Las Galletas and Punta del Hidalgo) and two reference areas on the Island of Tenerife (Canary Islands, Spain) were analyzed for butyrylcholinesterase (BChE) activity. Serum BChE activity was characterized first by in vitro experiments using selective substrates and inhibitors. Of the total cholinesterase (ChE) activity, 74% could be attributed to BChE activity. This portion of the total ChE activity was inhibited dose dependently by tetraisopropyl pyrophosphoramide and hydrolyzed the substrate butyrylthiocholine iodide. No enzyme inhibition was observed at high substrate concentration. Twenty-one lizards collected from agricultural sampling sites showed significant inhibition (p &lt; 0.001) of BChE activity (mean ± standard deviation [SD] of 4.66 ± 2.63 μmol/min/ml for lizards from Las Galletas and 5.13 ± 1.48 for lizards from Punta del Hidalgo) compared with BChE activity for lizards from the reference sites (6.35 ± 1.75 μmol/min/ml). Las Galletas had the highest number of lizards (22%) with significantly inhibited BChE activity. In vitro assays showed that 10−4 M pyridine-2-aldoxime methochloride (2-PAM) reactivated dichlorvos- or paraoxon-inhibited BChE activity within a 60-min incubation period. Almost all serum samples with depressed BChE activity that were collected from lizards from agricultural areas responded to 2-PAM reactivation of enzyme activity (8–60% increase in enzyme activity). Reactivation by treatment with 2-PAM confirmed that the depression of BChE activity was attributable to organophosphorus (OP) compounds. Evaluation of BChE activity levels and the chemical reactivation of serum BChE activity in G. galloti using 2-PAM was found to be a sensitive indicator of G. galloti exposure to OP compounds.
Responses to selection for cadmium resistance in the least killifish, Heterandria formosa
Authors: Xie Lingtian , Klerks Paul L. 
Published: March 2010

Abstract
An artificial selection experiment was conducted for six generations to investigate the responses to selection for cadmium resistance in the least killifish, Heterandria formosa. There was a rapid response to selection. After only one generation of selection, two of the three selection lines had an increased resistance to cadmium, while all three selection lines had an elevated resistance by the next generation. After six generations of selection, fish from the selection lines survived about three times as long as control line fish when exposed to cadmium. Realized heritability for cadmium resistance was estimated to be 0.50. Cross-resistance to copper was studied in the F2, F3, and F6 generations; fish from the cadmium-resistant lines had a longer survival time than those from the control lines. Resistance to heat was investigated in the F2, F3, and F5 generations; the cadmium-resistant lines had a significantly shorter survival time than the control lines. Our results showed that evolution of resistance to cadmium was rapid, that cross-resistance to copper occurred, and that the evolution of resistance to cadmium was accompanied by a trade-off (fitness costs) as evidenced by the reduced heat tolerance.
Factors influencing the design of bioaccumulation factor and biota-sediment accumulation factor field studies
Authors: Burkhard Lawrence P. 
Published: March 2010

Abstract
A series of modeling simulations was performed to evaluate the underlying factors and principles that drive the uncertainty in measured bioaccumulation factors (BAFs) and biota-sediment accumulation factors (BSAFs) for fish, and to determine which sampling designs minimize those uncertainties. Temporal variability of chemical concentrations in the water column, and the metabolism rate and n-octanol-water partition coefficient (Kow) for the chemical were determined to be the dominant factors that influenced the field-sampling design. Spatial variability of the chemical concentrations, food web structure, and the sediment-water column concentration quotient had a lesser importance upon the overall design. The simulations also demonstrated that collection of composite water samples in comparison to grab water samples resulted in reductions in the uncertainties associated with measured BAFs. Some illustrative sampling design structures for BAF and BSAF measurements based upon the temporal variability of chemical concentrations in the water column and the metabolism rate and Kow for the chemical were developed. These illustrative designs provided a sense of how sampling design structures, that is, the number and spacing over time of sampling events, might be influenced by differences in temporal variabilities, metabolism rates, and Kow. Although the importance of spatial variability was discounted as a major factor in the design process, sampling of water and sediment across the immediate home range of the sampled organism is required for successful measurements because poor spatial coordination of organism, water, or sediment samples will yield BAFs and BSAFs with large and unknown biases.
The effects of chronic cadmium exposure on American toad (Bufo americanus) tadpoles
Authors: James Stacy M. , Little Edward E. 
Published: March 2010

Abstract
American toad (Bufo americanus) tadpoles were exposed to cadmium from shortly after hatching through metamorphosis. Cadmium at 540 μg/L decreased percentage survival and metamorphosis; 5 and 54 μg/L increased growth relative to controls. Amphibians exposed to cadmium as tadpoles may be less tolerant of natural stressors in the terrestrial environment.
Dietary oral exposure to 1,3,5-trinitro-1,3,5-triazine in the northern bobwhite (Colinus virginianus)
Authors: Gogal Robert M. , Johnson Mark S. , Larsen Calvert T. , Prater Mary R. , Duncan Robert B. , Ward Daniel L. , Lee Robyn B. , Salice Christopher J. , Jortner Bernard , Holladay Steven D. 
Published: March 2010

Abstract
The potential risk to wildlife from exposure to explosives, including 1,3,5-trinitro-1,3,5-triazine (RDX), has been an issue at numerous U.S. military installations where these substances are found in soil and water. Presently, no data describing the effects of RDX exposure in avian species exist. Therefore, an acute lethal dose (ALD) and 14- and 90-d subchronic dietary exposures to RDX were evaluated in a species potentially present at many contaminated sites, i.e., the northern bobwhite (Colinus virginianus). The ALDs for females and males were 187 and 280 mg/kg, respectively. Data from the 14-d dietary trial suggested that RDX exposure inhibited food consumption, weight gain, and egg production. Dietary RDX exposure for 90-d produced a dose-dependant decreasing trend in total feed consumption, total egg production, and hen-housed production parameters. These collective data suggest that quail may respond differently to oral RDX exposure compared with mammals.
Comparison of metal accumulation in mussels at different local and global scales
Authors: Blackmore Graham , Wang Wen-Xiong 
Published: March 2010

AbstractCadmium and zinc uptake from the dissolved phase, assimilation efficiency (AE) from the dietary phase, and body burden as well as clearance rate were measured in green mussels, Perna viridis, and blue mussels Mytilus edulis, M. galloprovincialis and Mytilus trossulus. Perna viridis was collected from four sites differentially enriched with trace metals in Hong Kong and blue mussels were collected from different climatic zones, i.e., subarctic and temperate, to allow comparisons with the more tropical green mussels. Despite similar shell length, the dry weight of mussels varied significantly between sites and species and this had a large effect on Cd and Zn accumulation, clearance rate, and metal body burden. All data were, therefore, weight adjusted to allow comparison without this confounding factor. Trace-metal body concentrations were significantly different between sites, and P. viridis collected from Tsing Yi, Hong Kong, had the highest levels of all measured metals when compared with other Hong Kong sites. There was, however, no relationship between the degree of metal enrichment and the Cd and Zn uptake (both from dissolved and particulate sources) and clearance rates. Furthermore, Cd and Zn uptake (dissolved and particulate) and clearance rate varied little between species or climatic zones of collection. Thus, over the range of body trace-metal concentrations measured and between mussel species over large geographical distances and climatic zones, the uptake rates, AEs, and clearance rates are similar when measured under the same laboratory conditions after body-size correction. When other factors such as salinity are also corrected, biomonitoring data from different areas and even utilizing different mussel species may be directly comparable. This study therefore provides important evidence in support of Mussel Watch Programs.
Disturbances to metal partitioning during toxicity testing of iron(II)-rich estuarine pore waters and whole sediments
Authors: Simpson Stuart L. , Batley Graeme E. 
Published: March 2010

Abstract
Metal partitioning is altered when suboxic estuarine sediments containing Fe(II)-rich pore waters are disturbed during collection, preparation, and toxicity testing. Experiments with model Fe(II)-rich pore waters demonstrated the rates at which adsorptive losses of Cd, Cu, Ni, Mn, Pb, and Zn occur upon exposure to air. Experiments with Zn-contaminated estuarine sediments demonstrated large and often unpredictable changes to metal partitioning during sediment storage, removal of organisms, and homogenization before testing. Small modifications to conditions, such as aeration of overlying waters, caused large changes to the metal partitioning. Disturbances caused by sediment collection required many weeks for reestablishment of equilibrium. Bioturbation by benthic organisms led to oxidation of pore-water Fe(II) and lower Zn fluxes because of the formation of Fe hydroxide precipitates that adsorb pore-water Zn. For five weeks after the addition of organisms to sediments, Zn fluxes increased slowly as the organisms established themselves in the sediments, indicating that the establishment of equilibrium was not rapid. The results are discussed in terms of the dynamic nature of suboxic, Fe(II)-rich estuarine sediments, how organisms perturb their environment, and the importance of understanding chemistry in toxicity testing with whole sediments or pore water. Recommendations are provided for the handling of sediments for toxicity testing.
Sublethal energetic responses byPisidium amnicum(Bivalvia) exposed to pentachlorophenol at two temperatures
Authors: Heinonen Jari , Penttinen Olli-Pekka , Holopainen Ismo J. , Kukkonen Jussi V. K. 
Published: March 2010

AbstractSublethal effects of pentachlorophenol (PCP) were studied in the freshwater clam Pisidium amnicum by examining the cause-effect relationship between PCP body burden and the rate of the whole animal heat output. In addition, the modifying effects of temperature (7 and 15°C) and trematode parasites as natural stress factors were assessed. Results showed that even a low PCP body burden was sufficient to increase the heat output during the periods of aerobic metabolism and the magnitude of responses increased linearly with increasing body burden. During a valve-closure period, however, PCP had no effect on anaerobic heat output. The rise of the maximum heat output in response to PCP was more pronounced at the higher temperature. The response in heat output was similar in both infected and uninfected clams, but the general level of heat output was lower in infected clams. The increasing PCP body burden also increased the duration of valve-closure time. The results of this study suggested that microcal-orimetry could be a useful tool in assessing sublethal responses by the clam, which offers several calorimetrically measurable parameters such as aerobic and anaerobic heat output and behavior.
Adsorption, complexation, and phytoavailability of copper as influenced by organic manure
Authors: Bolan Nanthi , Adriano Domy , Mani Senniappan , Khan Afiqur 
Published: March 2010

Abstract
Copper (Cu) is bound strongly to clay minerals and organic matter in soils, and forms both insoluble and soluble organic complexes with organic carbon. In this experiment, the effect of five manure composts (biosolid, farmyard manure, spent mushroom, pig manure, and poultry manure) on the adsorption and complexation of Cu in a mineral soil (Manawatu sandy soil, Palmerston North, New Zealand) low in organic matter content was examined. The effect of biosolid on the uptake of Cu from the soil, treated with various levels of Cu (0–400 mg/kg soil), was examined by using mustard (Brassica juncea L.) plants. The redistribution of the added Cu in soil was evaluated by a chemical fractionation scheme. Addition of manure compost increased the adsorption and complexation of Cu by the soil. At the same level of total organic carbon addition, a significant difference was found in the extent of Cu adsorption among the manure-amended soils. However, less difference was found in the amount of Cu complexed among the manure-amended soils. A significant inverse relationship was found between the extent of Cu adsorption and the dissolved organic carbon (DOC) in the manure-amended samples, indicating that DOC formed soluble complexes with Cu. Increasing addition of Cu increased Cu concentration in plants, resulting in decreased plant growth at high levels of Cu (i.e., phytotoxicity). Addition of biosolid was found to be effective in reducing the phytotoxicity of Cu at high levels of Cu addition. Significant relationships were found between dry matter yield and total Cu or free Cu2+ concentration in soil solution. Addition of biosolid decreased the concentration of the soluble and exchangeable Cu fraction but increased the concentration of the organic-bound Cu fraction in soil.
General fugacity-based model to predict the environmental fate of multiple chemical species
Authors: Cahill Thomas M. , Cousins Ian , Mackay Donald 
Published: March 2010

Abstract
A general multimedia environmental fate model is presented that is capable of simulating the fate of up to four interconverting chemical species. It is an extension of the existing equilibrium criterion (EQC) fugacity model, which is limited to single-species assessments. It is suggested that multispecies chemical assessments are warranted when a degradation product of a released chemical is either more toxic or more persistent than the parent chemical or where there is cycling between species, as occurs with association, disassociation, or ionization. The model is illustratively applied to three chemicals, namely chlorpyrifos, pentachlorophenol, and perfluorooctane sulfonate, for which multispecies assessments are advisable. The model results compare favorably with field data for chlorpyrifos and pentachlorophenol, while the perfluorooctane sulfonate simulation is more speculative due to uncertainty in input parameters and the paucity of field data to validate the predictions. The model thus provides a tool for assessing the environmental fate and behavior of a group of chemicals that hitherto have not been addressed by evaluative models such as EQC.
Identification of phototransformation products of prednisone by sunlight: Toxicity of the drug and its derivatives on aquatic organisms
Authors: DellaGreca Marina , Fiorentino Antonio , Iesce Maria Rosaria , Isidori Marina , Nardelli Angela , Previtera Lucio , Temussi Fabio 
Published: March 2010

Abstract
Solar simulator irradiation of an aqueous suspension of prednisone, a widely prescribed drug, produces seven photochemical derivatives. The compounds have been identified on the basis of their physical features. All the chemicals have been tested to evaluate their toxic effects on freshwater organisms from different trophic levels. The rotifer Brachionus calyciflorus and two crustaceans, the cladoceran Daphnia magna and the anostracan Thamnocephalus platyurus, were used to perform acute toxicity tests. Chronic toxicity tests have been performed on the alga Pseudokirchneriella subcapitata (formerly known as Selenastrum capricornutum) and the crustacean Ceriodaphnia dubia. The results showed low acute and chronic toxicity of prednisone. Some of the photoproducts had high toxic effects on C. dubia.
Copper bioaccumulation by the freshwater snail Lymnaea peregra: A toxicological marker of environmental and human health?
Authors: Pyatt F. Brian , Metcalfe Matthew R. , Pyatt Andrea J. 
Published: March 2010

Abstract
Snails (Lymnaea peregra) were exposed to both low and high concentrations of copper (as copper nitrate) under controlled conditions and then were sacrificed and dissected; various tissues/organs were removed and subsequently analyzed by atomic absorption spectrophotometry to determine both the copper concentration and the nature of localization. At low concentrations, bioaccumulation was evident in various tissues/organs; a dose response occurred in tissues derived from both the head and foot. At high concentrations, the copper concentrations of the liver-like body and kidney became massively enhanced. There was some variability in the ranking of tissues/organs with regard to copper bioaccumulation—this was predominantly linked to the copper concentration to which the snails were exposed. Mechanisms of copper bioaccumulation are reviewed and comparisons with other organisms made.
Predicting sediment toxicity using logistic regression: A concentration-addition approach
Authors: Smith Eric P. , Robinson Tim , Field L. Jay , Norton Susan B. 
Published: March 2010

Abstract
The question posed in this article is how useful the chemical concentration measurements for predicting the outcome of sediment toxicity tests are. Using matched data on sediment toxicity and sediment chemical concentrations from a number of studies, we investigated several approaches for predicting toxicity based on multiple logistic regression with concentration-addition models. Three models were found to meet criteria for acceptability. The first model uses individual chemicals selected using stepwise selection. The second uses derived variables to reflect combined metal contamination, polycyclic aromatic hydrocarbon (PAH) contamination, and the interaction between metals and PAHs. The third and final model is a separate species model with derived variables. Overall, these models suggest that toxicity may be correctly predicted approximately 77% of the time, although prediction is better for samples identified as nontoxic than for those known to be toxic.
Comparison of the response of three microalgae species exposed to elutriates of estuarine sediments based on growth and chemical speciation
Authors: Mucha Ana P. , Leal M. Fernanda C. , Bordalo Adriano A. , Vasconcelos M. Teresa S. D. 
Published: March 2010

AbstractThe elutriate sediment toxicity test (ESTT) provides a measure of the amount of a substance that is exchanged between the sediment and the aqueous phase during resuspension processes such as floods or dredging operations. This study used ESTT with two complementary aims: a comparison of the elutriates of two estuarine sediments (anaerobic muddy [A] and aerobic sandy [B]) in terms of toxicity and a comparison of the response of three different microalgae (Emiliania huxleyi (coccolithophore), Dunaliella minuta (green alga), and Phaeodactylum tricornutum (diatom)) to each elutriate in terms of growth, heavy metals uptake, and organic ligands release or uptake in order to find eventual differences of sensitivity. The interpretation of the results was based on chemical speciation in the culture media. Both elutriates, particularly A, were much richer than seawater (control medium) in some heavy metals and organic ligands able to bind strongly heavy metals. Elutriate A slightly inhibited P. tricornutum growth but stimulated growth of E. huxleyi and D. minuta. Elutriate B stimulated the growth of the three algal species. Therefore, the diatom behaved differently from both the coccolithophore and the green alga. Strong complexation of trace metals by organic ligands could be the cause of absence of the metallic toxicity of the elutriates. Growth inhibition of P. tricornutum in elutriate A could be caused by ammonia‐N and/or organic compounds. The concentration of the organic ligands decreased markedly (about 75%) in both elutriates after 10 d of incubation in contrast to the control culture, where their concentration increased about 50% because of exudation. This phenomenon was interpreted to result from ligand uptake by the algae, free or as metal complexes. This work demonstrated that beside the evaluation of toxicity of free heavy metals to alga species, the organic ligands must not be ignored. Depending on the amount of ligand present, the toxicity can be reduced (sequestration) or enhanced (better availability through uptake of metal‐ligand complexes). Since the applied ESTT is a standard procedure (U.S. Environmental Protection Agency) for the evaluation of dredged material proposed for ocean disposal, it is necessary to discuss results obtained during toxicity tests with such elutriates in detail.
Relationships between mercury body concentrations, standard metabolic rate, and body mass in eastern mosquitofish (Gambusia holbrooki) from three experimental populations
Authors: Hopkins William A. , Tatara Christopher P. , Brant Heather A. , Jagoe Charles H. 
Published: March 2010

AbstractEastern mosquitofish (Gambusia holbrooki) were sampled from three experimental populations (two Hg-exposed populations and one reference population) to determine whether transgenerational exposure (lifelong exposure of multiple generations) to Hg adversely affects standard metabolic rate (SMR). Mosquitofish subjected to lifelong Hg exposure accumulated significant concentrations of Hg in their tissues compared to fish from the reference population (mean: 3.89–4.13 vs 0.08 μHg/g wet mass, respectively). Less than 10% of the variability in Hg tissue concentrations could be explained by fish body mass, likely because of the short life span and/or dietary habits of this species. Despite the high body burdens of Hg in exposed fish, we found no significant difference in SMR among individuals from Hg-exposed or reference populations. Our findings contrast recent laboratory work describing elevated SMR in mosquitofish exposed to 100 μg/L dissolved inorganic Hg for 48 h. To account for contrasting results between studies, we hypothesize that acute exposure to dissolved inorganic Hg damages gill epithelium, resulting in increased metabolic rate, but that lifelong Hg exposure via trophic uptake of methyl mercury does not affect fish respiratory structures. Alternative hypotheses include the possibility that G. holbrooki is a species that can tolerate high body burdens of Hg or that more than four years of genetic isolation during Hg exposure (8–12 generations) resulted in selection for Hg-tolerant or -resistant individuals.