bluuebunny/crossref_metadata_2025_split huggingface dataset:
A method for partitioning cadmium bioaccumulated in small aquatic organisms
Authors: Siriwardena P.P.G. Sunil N. , Rana Krishen J. , Baird Donald J. 
Published: March 2010

Abstract
A series of laboratory experiments was conducted to evaluate bioaccumulation and surface adsorption of aqueous cadmium (Cd) by sac-fry of the African tilapia Oreochromis niloticus. In the first experiment, the design consisted of two cadmium treatments: 15 μg Cd · L−1 in dilution water and a Cd-ethylenediaminetetraacetic acid (Cd-EDTA) complex at 15 μg · L−1, and a water-only control. There were five replicates per treatment and 40 fish per replicate. It was found that EDTA significantly reduced the bioaccumulation of cadmium by tilapia sac-fry by 34%. Based on these results, a second experiment was conducted to evaluate four procedures: a no-rinse control; rinsing in EDTA; rinsing in distilled water; and rinsing in 5% nitric acid, for removing surface-bound Cd from exposed sac-fry. In this experiment, 30 fish in each of five replicates were exposed to 15 μg Cd · L−1 for 72 h, processed through the rinse procedures, and analysed for total Cd. The EDTA rinse treatment significantly reduced (p &lt; 0.05) Cd concentrations of the exposed fish relative to those receiving no rinse. It was concluded that the EDTA rinse technique may be useful in studies evaluating the partitioning of surface-bound and accumulated cadmium in small aquatic organisms.
The effects of sublethal dimethoate exposure on the locomotor behavior of the collembolan Folsomia candida (Isotomidae)
Authors: Sørensen Freddy Fisker , Bayley Mark , Baatrup Erik 
Published: March 2010

Abstract
The locomotor behavior of the collembolan Folsomia candida Willem 1902 (Isotomidae) was automatically quantified during exposure to soil treated with sublethal concentrations of dimethoate. During the 36 h of measurement, significant changes were seen in walked distance, mean velocity, and turning rate. It is concluded that these end points provide a sensitive measure of toxic stress.
A mechanistic model of contaminant-induced feeding inhibition in Daphnia magna
Authors: Allen Yvonne , Calow Peter , Baird Donald J. 
Published: March 2010

Abstract
Particles in water ubiquitously carry a net negative charge. It was hypothesised that the interaction between suspended particles and pollutants in water results in a process of adsorption that can be related to the charge of the pollutant concerned, and that this is a potential route of pollutant uptake by aquatic animals such as particle-grazing zooplankton. Experiments with the alga Chlorella vulgaris were conducted to test the hypothesis that pollutant-induced feeding inhibition in the cladoceran Daphnia magna was dependent on this mechanism. Using compounds differing in charge, results supported the hypothesis that, while all compounds were capable of causing feeding inhibition, electropositive species such as cadmium induced effects close to the chronic no-effect concentration, whereas electronegative species such as vanadium induced effects only at or close to lethal levels. It was suggested that for those compounds capable of causing feeding inhibition at sublethal concentrations, this inhibition would be a key mechanism impairing reproduction and growth, with potential consequences for grazing animals at population and community levels in natural ecosystems.
Predicting chronic lethality of chemicals to fishes from acute toxicity test data: Theory of accelerated life testing
Authors: Sun Kai , Krause Gary F. , Mayer Foster L. , Ellersieck Mark R. , Basu Asit P. 
Published: March 2010

Abstract
A method for modeling aquatic toxicity data based on the theory of accelerated life testing is presented, and a procedure for maximum likelihood fitting the proposed model is developed. The procedure is computerized as software, which can predict chronic lethality of chemicals using data from acute toxicity tests. A database of various chemicals and fish species was analyzed. When the calculated values of prediction were compared to the maximum acceptable toxicant concentrations obtained from actual chronic toxicity experiments, the new technique provided accurate predictions. Problems in using the “maximum acceptable toxicant concentration” and applications of the proposed method are discussed.
Fitness trade-offs of Selenastrum capricornutum strains selected for rapid growth on copper-spiked solidified nutrient medium
Authors: Benjamin Richard B. , Klaine Stephen J. 
Published: March 2010

Abstract
Stock (ancestral) cultures of Selenastrum capricornutum grew optimally in low Cu liquid nutrient medium (LNM) containing 0.004 μg L−1 Cu2+. Growth of stock cultures was optimized on low Cu solidified nutrient medium (SNM) containing 20 μg L−1 Cu2+. Cell strains (clones) were isolated from unusually large colonies on high Cu SNM (1,000 μg L−1 Cu2+). Most isolated strains performed the same as ancestral populations in high Cu LNM (50 μg L−1 Cu2+), but three strains grew more slowly. These “variant strains” were Cu tolerant on SNM (equal growth with low and high Cu) and produced larger colonies than did the ancestral population on both low and high Cu SNM. In contrast, colonies from ancestral cell samples grew more slowly in high versus low Cu SNM. No significant growth differences were observed between ancestral populations and variant strains in low Cu LNM, suggesting low fixed costs of adaptation to SNM. However, slower growth of variant strains in high Cu LNM constituted a fitness trade-off associated with adaptation. Rapid adaptation to pollution may often result in important biological trade-offs even when costs of adaptive mechanisms are low.
Transformation of benzonitriles in anaerobic sediment and in sediment extract
Authors: Masunaga Shigeki , Lee Wolfe N. , Carriera Laura 
Published: March 2010

Abstract
Transformations of para-substituted benzonitriles in sediment and in sediment extract were studied. In raw anaerobic sediment, most of the benzonitriles were transformed to benzoic acids without benzamide intermediates. Very slow disappearance of benzonitrile in autoclave-sterilized sediment was explained by the chemical hydrolysis, while relatively rapid decrease in γ-irradiation-sterilized sediment indicated another abiotic mechanism. Hence, extracted protein fraction from sediment active against benzonitrile was surveyed. The obtained active fraction transformed para-substituted benzonitriles to corresponding benzoic acids without any intermediates, which resembled reported nitrilase enzyme activity. Quantitative structure-reactivity relationship (QSRR) analyses of para-substituted benzonitrile transformation-rate constants in raw sediment and in sediment extract fraction indicated that both of them had some correlation with hydrophobicity. This contrasted with the chemical hydrolysis of these compounds, which was controlled by electronic substituent constant (Hammett σp). This was an encouraging sign that the obtained sediment extract fraction is possibly responsible at least for part of the reaction in raw sediment. Various reaction mechanisms are present for degradation of xenobiotics in anaerobic sediment. This study presented the possible abiotic mechanism attributable to protein fraction in sediment. Further studies are necessary to understand the total reaction mechanisms in aquatic sediment.
Modeling silver binding to gills of rainbow trout (Oncorhynchus mykiss)
Authors: Janes Nancy , Playle Richard C. 
Published: March 2010

Abstract
Rainbow trout (Oncorhynchus mykiss, 1–3 g) were exposed to ∼0.1 μM silver (Ag) (∼11 μg.L−1 Ag) for 2 to 3 h in synthetic soft water (Ca, Na ∼ 300 μM, pH 6.5–7.5) to which was added Ca, Na, H+, dissolved organic carbon (DOC), CI, or thiosulfate (S2O3). Gills were extracted and gill Ag concentrations were measured using graphite-furnace atomic absorption spectrophotometry. The concentrations of cations (Ca, Na, H+) and complexing agents (DOC, CI, S2O3) needed to keep Ag off the gills were used to calculate conditional equilibrium binding constants (K) at the gills. Log K for Ag-gill binding was 10.0, with approximately 1.3 nmol Ag binding sites per fish. All experimentally determined log K values were entered into an aquatic chemistry equilibrium model, MINEQL+, to predict Ag binding at trout gills. For a series of natural waters, model-predicted gill Ag concentrations correlated well with observed gill Ag concentrations, with one exception, very hard city of Waterloo tapwater. This exception may indicate a kinetic constraint on the thermodynamic basis of the model.
Acephate affects migratory orientation of the white-throated sparrow (Zonotrichia albicollis)
Authors: Vyas Nimish B. , Hill Elwood F. , Sauer John R. , Kuenzel Wayne J. 
Published: March 2010

Abstract
Migratory white-throated sparrows (Zonotrichia albicollis) were exposed to acephate (acetylphosphoramidothioic acid O, S-dimethyl ester), an organophosphorus pesticide, to determine its effects on migratory orientation and behavior. Birds were also exposed to polarizer sheets to determine the mechanism by which acephate may affect migratory orientation. Adult birds exposed to 256 ppm acephate a.i. were not able to establish a preferred migratory orientation and exhibited random activity. All juvenile treatment groups displayed a seasonally correct southward migratory orientation. We hypothesize that acephate may have produced aberrant migratory behavior by affecting the memory of the migratory route and wintering ground. This experiment reveals that an environmentally relevant concentration of a common organophosphorus pesticide can alter migratory orientation, but its effect is markedly different between adult and juvenile sparrows. Results suggest that the survival of free-flying adult passerine migrants may be compromised following organophosphorus pesticide exposure.
Determination and genotoxicity of high molecular mass polycyclic aromatic hydrocarbons isolated from coal-tar-contaminated sediment
Authors: Marvin Chris H. , Lundrigan John A. , McCarry Brian E. , Bryant Douglas W. 
Published: March 2010

Abstract
A bioassay-directed chemical fractionation methodology was used to identify the principal mutagenic compounds in an organic solvent extract of coal-tar-contaminated sediment from Sydney Harbour, Nova Scotia. Biological assays with Salmonella typhimurium bacteria with the addition of oxidative metabolism indicated that the majority of the mutagenic activity observed in the sediment extract was associated with the higher molecular mass polycyclic aromatic hydrocarbons (PAHs). A normal phase high-performance liquid chromatography (HPLC) technique was developed to separate the PAH-rich solvent extracts into fractions containing isomeric PAHs of a single benzologue class. These fractions were analyzed by probe mass spectrometry and gas chromatography-mass spectrometry (GC-MS), and subjected to biological assays using strain YG1025 with the addition of oxidative metabolism (4% and 10% S9). Fractions containing compounds of molecular weights 252, 276, 278, and 302 amu exhibited mutagenic activities of 930 + 125, 510 + 100, 250 + 40, and 370 + 140 rev/mg sediment, respectively. The molecular weight 252 and 276 amu fractions were further analyzed using reversed-phase HPLC and GC-MS to identify the individual PAHs responsible for the observed biological activity. High molecular mass PAHs including benzo[a]pyrene, benzo[ghi]perylene, indeno[1,2,3-cd]pyrene, and compounds of molecular weight 302 amu were found to be responsible for the majority of the mutagenic activity displayed by this complex environmental mixture.
Response threshold levels of selected organic compounds for rainbow trout (Oncorhynchus Mykiss)
Authors: Kaiser Klaus L.E. , McKinnon Mark B. , Stendahl Douglas H. , Pett Brian W. 
Published: March 2010

Abstract
The responses of 27 organic compounds, mainly chloromethanes, -ethanes, -ethenes, and -phenols, were investigated by exposing rainbow trout fingerlings to low microgram-per-liter concentrations in a darkened flow-through system for up to 1 h. Responses by the fish were followed continuously by observing ventilation rates (frequency and amplitude), swimming patterns, and general activity using the low-voltage electric fields generated by the fishes' activity. The lowest level of response was found for trichloroethylene at 5 μg/L. Dichloromethane, 1,1- and 1,2-dichloroethane, 1,1,1- and 1,1,2-trichloroethane, cis-1,2-dichloroethylene, 1,3-dichloropropene, and allyl acetate were responded to at concentrations of 10 μg/L, carbon tetrachloride at 15 μg/L, and 4-chlorophenol and 2,4-dichlorophenol at levels of 30 μg/L. Unsubstituted phenol was not responded to at levels of up to 50 μg/L.
Influence of developmental stage, salts and food presence on various end points using Caenorhabditis Elegans for aquatic toxicity testing
Authors: Donkin Steven G. , Williams Phillip L. 
Published: March 2010

Abstract
This study used a randomized block design to investigate the importance of several variables in using the free-living soil nematode Caenorhabditis elegans for aquatic toxicity testing. Concentration-response data were obtained on nematodes of various developmental stages exposed to four metals (Cd, Pb, Cu, and Hg) and a water-soluble organic toxicant, sodium pentachlorophenate (PCP), under conditions of varied solvent medium (with or without salts and with or without a bacterial food source). The end points measured were 24- and 96-h mortality LC50 value, as well as development of larval stages to adulthood and evidence of reproduction. The results suggest that nematodes of various ages respond similarly to a given toxicant for all end points measured, although adults cultured from eggs appeared more sensitive than adults cultured from dauer larvae. The most important environmental variable in determining toxicity was the medium in which the tests were conducted. The presence of potassium and sodium salts in the medium significantly (p &lt; 0.05) reduced the toxicity of many test samples. The presence of bacteria had little effect on 24-h tests with salts, but was important in 96-h survival and development. Based on sensitivity and ease of handling, adults cultured from eggs are recommended in both 24-h and 96-h tests.
Inducibility of a molecular bioreporter system by heavy metals
Authors: Klimowski Laura , Rayms-Keller Alfredo , Olson Ken E. , Beaty Barry , Carlson Jon , Yang Ray S. H. , Tessari John 
Published: March 2010

Abstract
We have developed a molecular bioreporter model for detecting an invertebrate response to heavy metals. The bioreporter system, pMt2-luc, utilizes a Drosophila melanogaster metallothionein promoter to regulate luciferase expression in stably transformed mosquito cells. The LucC5 clone, which was isolated from pMt2-luc transformed, hygromycin-resistant C6/36 (Aedes albopictus) cells, demonstrated a 12-fold increase in luciferase-specific activity 48 h after exposure to 13 ppm copper (Cu). In addition to Cu, exposure of LucC5 cells to 19 ppm lead (Pb) or 3 ppm mercury (Hg) for 48 h induced luciferase expression threefold and fourfold, respectively. Exposures of up to 30 ppm arsenic (As), 8 ppm cadmium (Cd), 7 ppm chromium (Cr), or 5 ppm nickle (Ni) had no effect on luciferase induction. LucC5 cells exposed to metal mixtures of 13 ppm Cu and 19 ppm Pb yielded an additive response with a 14-fold increase in luciferase expression. When organic chemicals such as phenol (3 ppm) were mixed with 13 ppm Cu, 19 ppm Pb, or 3 ppm Hg a significant reduction in luciferase activity was noted. Additionally, atomic absorption spectroscopy suggested that two of the metals, Cu and Pb, show marked differences in accumulation within the LucC5 cell line.
Moult frequency of the isopod Porcellio scaber, as a measure of zinc-contaminated food
Authors: Drobne Damjana , Štrus Jasna 
Published: March 2010

Abstract
The effect of zinc-contaminated leaf litter (250–10,000 μ/g dry wt.) diets on molting in Porcellio scaber, a terrestrial isopod was measured under controlled conditions. The duration of the premolt stage, the period between two successive ecdyses and the rate of molting, was followed during the exposure. Increased zinc concentration in the food caused prolongation of the molt cycle and decreased molt frequency. The duration of the premolt stage was not changed. Molt cycle was not affected drastically due to food deprivation. The application of molt cycle response to contaminated food in toxicity tests is discussed.
Interaction of environmental xenobiotics with a multixenobiotic defense mechanism in the bay mussel Mytilus galloprovincialis from the coast of California
Authors: Galgani Francois , Cornwall Roger , Toomey Barbara Holland , Epel David D. 
Published: March 2010

Abstract
A multixenobiotic defense mechanism similar to a P-glycoprotein multidrug transporter was characterized in the gills of the mussel Mytilus galloprovincialis from Monterey, California. Using a fluorescent dye assay, we measured multixenobiotic transport activity in individual gill cells and assessed the effects of inhibitors or competitive substrates on activity. Natural products that inhibit the mammalian transporter also affected dye transport in the mussel gill. Four moderately hydrophobic pesticides (dacthal, chlorbenside, sulfallate, and pentachlorophenol) and four highly hydrophobic xenobiotics (p,p′-DDT, p,p′-DDD, p,p′-DDE, and Aroclor 1254) all inhibited the efflux of dye from the gills, indicating their interaction with a multixenobiotic transport mechanism in this organism. The reactivity with these highly hydrophobic compounds seen in M. galloprovincialis differs from related transporters found in other organisms. A protein in the gill cross-reacts with antibodies directed against the mammalian multidrug transport protein. The level of protein can be assessed easily by dot blot procedures and may facilitate quantitation of protein levels in field situations.
Response of aquatic communities from a vermont stream to environmentally realistic atrazine exposure in laboratory microcosms
Authors: Gruessner Barry , Watzin Mary C. 
Published: March 2010

Abstract
The direct and indirect effects of the herbicide atrazine were assessed at the community level under exposure patterns likely to be experienced by stream organisms in Vermont. Both attached algae and benthic invertebrates were collected from a clean site using artificial substrates and established in recirculating 120–L laboratory microcosms. On day 1 of the 14–d experiment, three of six microcosms were treated with 5 μg/L atrazine. Concentrations were gradually reduced by replacing a portion of the water in the systems over time so that by day 7, atrazine concentrations were only about 1 μg/L. Direct effects of atrazine on algal biomass were assessed by measuring chlorophyll a concentrations in samples of attached algae. No differences in chlorophyll a were found between treatment and control microcosms. Potential indirect effects of reduced algal food availability on benthic invertebrate communities were assessed by comparing assemblages in treatment and control microcosms using both a functional (feeding) group classification and taxonomic composition. There were no significant differences in the functional or taxonomic composition of the benthic invertebrate communities; however, a greater number of insects emerged from the treatment microcosms early in the experiment compared to controls, suggesting some response to atrazine. Further community-level testing is needed to more clearly determine if atrazine is affecting stream organisms.
Effects of rodeo® and garlon® 3A on nontarget wetland species in central Washington
Authors: Gardner Susan C. , Grue Christian E. 
Published: March 2010

Abstract
Purple loosestrife (Lythrum salicaria) is an invasive wetland perennial that became established in northeastern North America in the early 1800s. Despite its designation as a noxious weed, its distribution has continued to expand. Treatment with herbicides is the most widely used means of controlling purple loosestrife. This study examined the nontarget effects of two herbicides, Rodeo® and Garlon® 3A, currently used or being considered for use in controlling purple loosestrife in Washington State, respectively. Growth and/or survival of duckweed, Daphnia, and rainbow trout were monitored for at least 24 h following an application of each herbicide. Free-living water column and benthic invertebrates were monitored 24 h and 7 d post-spray using activity traps and sediment cores. Neither chemical was associated with significant decreases in survival or growth of the bioassay organisms, with the exception that growth of duckweed was reduced 48 h after exposure to Rodeo. Nor were significant decreases in the abundance of free-living aquatic invertebrates detected following the herbicide applications. Results suggest that neither herbicide, at the application rates used, poses a hazard to aquatic invertebrates in wetlands in central Washington. However, Rodeo, because it is a broad-spectrum herbicide, may pose a greater hazard to nontarget aquatic vegetation.
Comparison of the response of bacterial luminescence and mitochondrial respiration to the effluent of an oil refinery
Authors: Riisberg Marianne , Bratlie Ellen , Stenersen Jørgen 
Published: March 2010

Abstract
The effects of oil refinery effluents on rat mitochondrial respiration and on the luminescence of the bacterium Photo-bacterium phosphoreum were compared. Mitochondria from male Wistar rat livers were exposed to different concentrations of refinery effluents in a semiclosed 3–ml reaction vessel. Respiration was measured polarographically with an oxygen electrode. Effects on P. phosphoreum were measured by the standard test developed by Microbics. The mitochondrial method showed EC50s in the range from 1 to 7.5%, while Microtox gave EC50 in the range from 30 to 42%. The higher sensitivity of mitochondria may be exploited in the development of a sensitive biosensor for toxicity of oil refinery effluents.
Reproductive success, developmental anomalies, and environmental contaminants in double-crested cormorants (Phalacrocorax auritus)
Authors: Larson Jill M. , Karasov William H. , Sileo Louis , Stromborg Kenneth L. , Hanbidge Barbara A. , Giesy John P. , Jones Paul D. , Tillitt Donald E. , Verbrugge David A. 
Published: March 2010

Abstract
To test an association between environmental contaminants and the prevalence of congenital anomalies in colonial waterbirds, we collected representative eggs for chemical analysis from double-crested cormorant nests at colonies in Lake Michigan, Wisconsin, USA, and Lake Winnipegosis, Manitoba, Canada, and periodically revisited the nests to determine the hatching success, survivorship of hatchlings, and number of deformed hatchlings in the remainder of each clutch. Total concentrations of polychlorinated biphenyls (PCBs) in eggs were determined by capillary gas chromatography. The combined activity of planar chlorinated hydrocarbons (PCHs) in the eggs was measured in an in vitro bioassay based on the induction of ethoxyresorufin-O -deethylase (EROD) activity in rat hepatoma cells. The combined EROD induction activity was expressed as 2,3,7,8–tetrachlorodibenzo-p -dioxin equivalents (TCDD-EQ). Total concentrations of PCBs and TCDD-EQ were seven to eight times greater in eggs from Lake Michigan (7.8 μg/g and 138 pg/g, respectively) than in those from Lake Winnipegosis (1.0 μg/g and 19 pg/g, respectively). The proportion of eggs hatching at the Lake Michigan colony (59%) was less (p &lt; 0.05) than at Lake Winnipegosis (70%), and the prevalence of hatchlings with deformed bills was greater (p &lt; 0.001) at Lake Michigan (0.79 vs. 0.06%). However, within the Lake Michigan colony, concentrations of PCBs and TCDD-EQ were not correlated with either hatching success or the occurrence of deformities in nestlings.