bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modulation of mixed-function oxidase activity in black-headed gulls living in anthropic environments: Biochemical acclimatization or adaptation?
Authors: Fossi M. Cristina , Leonzio Claudio , Focardi Silvano , Lari Lorena , Renzoni Aristeo 
Published: March 2010

Abstract
This study was conducted to explore the role of the mixed-function oxidase (MFO) detoxication system in the “biochemical acclimatization” or adaptation of gulls to anthropic environments. In three different populations of black-headed gull (Larus ridibundus) feeding in a lagoon, in municipal and industrial landfills, MFO microsomal hepatic activities (aldrin epoxidase, 7-ethoxyresorufin-O-deethylase, NADPH-cytochrome c reductase, NADH-cytochrome c reductase, and NADH-ferricyanide reductase), microsomal α-naphthylacetate esterase activity, cytochrome P-450 forms, and chlorinated hydrocarbon residues were determined. Induction tests and in vitro comparative kinetics studies were completed between the different populations of gulls. The detoxicant activities of the MFO system were much higher in the landfill gulls, especially those of the industrial landfill, than in lagoon gulls. Lineweaver-Burk plots for aldrin epoxidase show an apparent Km four to five times lower in the gulls of the industrial landfill than in the other two populations. The origin of the potentiated detoxication activities in landfill gulls is investigated and the hypotheses of biochemical acclimatization and genetic adaptation are discussed.
Dietary uptake and biomagnification of four chlorinated hydrocarbons by guppies
Authors: Clark Kathryn E. , Mackay Donald 
Published: March 2010

Abstract
Laboratory experiments are described in which guppies (Poecilia reticulata) were fed food containing hexachlorobenzene, mirex, 2,2′,3,3′,4,4′,5,6′-octachlorobiphenyl, and octachlorodibenzofuran. The chemical concentrations in the food and the feeding rate were varied to determine the effect of these variables on the assimilation efficiency. Increasing the dietary intake by increasing the concentration (or fugacity) of a chemical in the food causes a proportional increase in the steady-state concentration or fugacity of the chemical in the fish; i.e., the assimilation efficiency is constant. Increasing the dietary intake by increasing the feeding rate produces a less than proportional increase in the steady-state concentration or fugacity of the chemical in the fish. This apparent drop in assimilation efficiency is the result of an increased rate of loss by egestion. Mirex and octachlorobiphenyl were observed to biomagnify; i.e., the steady-state fugacities achieved in the fish exceeded the fugacities in the food. These findings are in accord with the assertions of a fugacity model of bioaccumulation.
Acute toxicities of permethrin, fenitrothion, carbaryl and carbofuran to mosquito larvae during single- or multiple-pulse exposures
Authors: Parsons J. T. , Surgeoner G. A. 
Published: March 2010

Abstract
The acute toxicity to third-instar Aedes aegypti (L.) of two 1-h exposures to each of five insecticides (technical permethrin, microencapsulated permethrin, fenitrothion, carbaryl, and carbofuran) was determined with static toxicity tests. The toxicity of two 1-h exposures to these test compounds, separated by a 6-h insecticide-free period, was compared to that of continuous 2-h exposures. Acute toxicity was expressed as LC50 values based on survival to the adult stage. The LC50 for two 1-h exposures to microencapsulated permethrin (180 μg/L) was significantly lower than that for a continuous 2-h exposure (250 μg/L). There was no significant difference between LC50 values for two 1-h and continuous 2-h exposures for each of technical permethrin (2.03–2.32 μg/L), fenitrothion (49.4–48.8 μg/L), carbaryl (3,040–3,470 μg/L, and carbofuran (1,590–2,130 μg/L).
Increasing time between two 1-h exposures to carbaryl from 6 to 24 h did not significantly affect acute toxicity (LC50 values were 3.0 mg/L and 3.8 mg/L, respectively). The LC50 for four 1-h exposures to carbaryl each separated by a 12-h period in clean water (LC50 = 1.7 mg/L) was not significantly different from that of a continuous 4-h exposure (LC50 = 1.4 mg/L). These results suggest that there was no recovery from the effect of insecticide poisoning during the insecticide-free period between exposures.
Degradation of toluene and p-xylene in anaerobic microcosms: Evidence for sulfate as a terminal electron acceptor
Authors: Haag Franziska , Reinhard Martin , Mccarty Perry L. 
Published: March 2010

Abstract
The degradation of aromatic hydrocarbons (benzene, toluene, ethylbenzene, p-xylene, o-xylene, 1,3,5-trimethylbenzene, and naphthalene) under anaerobic conditions was studied in column microcosms developed with aquifer material from the vicinity of a gasoline spill at Seal Beach, California. In one column, which did not receive any electron acceptors other than those naturally present (sulfate and carbon dioxide), more than 60% of the toluene was oxidized to CO2. The other six added substrates were not degraded when the toluene supply was constant. In another column, the addition of toluene was discontinued after 126 d, which coincided with the onset of p-xylene degradation. Addition of sulfate, the only electron acceptor that was detected, stimulated the transformation of toluene in batch experiments.
Evaluation of gas chromatography with electrolytic conductivity detection and electron capture detection and use of negative chemical ionization GC-MS for the analysis of PCBs in effluents
Authors: Greaves John , Harvey Ellen , Huggett Robert J. 
Published: March 2010

Abstract
Gas chromatography with electrolytic conductivity detection and electron capture detection in combination with gas chromatography-mass spectrometry, operated in the electron capture negative chemical ionization mode, were evaluated as techniques for the analysis of polychlorinated biphenyls in wastewater from an industrial facility. The specificity of the electrolytic conductivity detector reduced sample turnaround time because extracts could be analyzed without fractionation or cleanup Using a 2 L sample, this methodology had a quantification limit, based on Aroclor 1260, of 0.1 μg/L and a detection limit of approximately 0.03 μg/L The electron capture detector was subject to interferences from nonhalogenated compounds and required additional sample cleanup Electron capture negative chemical ionization gas chromatography-mass spectrometry was highly specific and provided full mass spectra of polychlorinated biphenyl congeners at the same quantification limit. Effluents from the facility had polychlorinated biphenyl concentrations of 0.1 to 1 μg/L.
Desorption of tetrachloroethene and 1,2-dibromo-3-chloropropane from aquifer sediments
Authors: Pignatello Joseph J. 
Published: March 2010

Abstract
Desorption of tetrachloroethene (TeCE) or 1,2-dibromo-3-chloropropane (DBCP) from aquifer sediment (0.19% organic carbon) was monitored following sorption for 6 or 30 d in 100 μM aqueous solutions. The compounds were desorbed by a previously developed purge technique in which a third phase of Tenax GC® polymeric adsorbent beads provided a sink for desorbed chemical, thereby simulating desorption to infinite dilution. Sorbed concentrations in the sediments were quantified by hot acetone extraction of sacrificed replicates. More than 95% of the initial sorbed compound was desorbed within the first 4 d, but a persistent fraction (8–15 μg/kg, 0.4 to 1%) remained associated with the sediments for at least 35 d. The desorption curves were little affected by the prepurge sorption time. The results may rationalize the unexpectedly high sediment-associated concentrations of a similar compound (1,2-dibromoethane) in a long-contaminated aquifer.
Evaluation of selected lipid methods for normalizing pollutant bioaccumulation
Authors: Randall Robert C. , Lee Henry , Ozretich Robert J. , Lake James L. , Pruell Richard J. 
Published: March 2010

AbstractCurrent environmental models use organism lipid concentrations to estimate maximum pollutant bioaccumulation potentials. This collaborative study has shown that significantly different lipid concentrations (3.5X) are found when using common, but different, extraction solvents and methods. Based on these variable lipid values, models that estimate tissue pollutant concentrations normalized to lipid will give significantly different bioaccumulation estimates. To reduce that variability, a standard lipid method needs to be developed or adopted.
An evaluation of a naidid oligochaete as a toxicity test organism
Authors: Smith David P. , Kennedy James H. , Dickson Kenneth L. 
Published: March 2010

AbstractConcern over sediment toxicity has increased the need for toxicity test information with organisms that inhabit sediments. Oligochaetes are exposed to toxicants through feeding and body contact with sediments and interstitial water. Chronic testing with oligochaetes has historically focused on tubificids with test lengths of 1 year or more to encompass several generations. Most naidid oligochaetes have generation times of 3 to 7 d. The cosmopolitan-distributed naidid Pristina leidyi Smith 1896 has potential for sediment toxicity testing. Cultures of Pristina leidyi were maintained in the laboratory for over 2 years. A rabbit chow suspension provided both substrate and food source. A reproducing viable culture with little variation in growth was maintained at 24 ± 4°C and a 16:8-h light:dark photoperiod. Population growth in a characterized reference sediment peaked at 24 d with an increase in variation. It is recommended that test lengths should not exceed 18 d. The 48-h LC50s for cadmium and vanadium using Pristina leidyi were 215 μg/L and 30,830 μg/L, respectively, at a water hardness of 95 mg/L as CaCO3.
The hazard assessment of pulp and paper effluents in the aquatic environment: A review
Authors: Owens James William 
Published: March 2010

Abstract
The hazard assessment of pulp and paper effluents in the aquatic environment is a complex task. Hundreds of individual compounds in pulping effluents and site-specific differences in processes, effluent treatment, and receiving ecosystems hinder hazard assessment. As a result, it is difficult to relate environmental effects with specific contaminants. Conventional parameters such as organic and nutrient loadings, solids deposition, and color complicate efforts to define chemical toxicants by causing environmental impacts at community and population levels. Reproduction is the most sensitive, consistent, and relevant end point tested to date in the laboratory, in mesocosms and experimental streams, and in field situations near some pulping discharges. Despite the application of a wide range of within-organism measurements, only the induction of mixed-function oxidase activities has been associated with exposure to particular effluent compounds in field situations. No complete mechanism of toxic action has been demonstrated that connects contaminant exposure, within-organism responses, whole-organism effects, and effects at the population and the community levels. Hazard assessments of pulping effluents require multidisciplinary efforts that integrate chemical, toxicological, and biological data at several organizational levels. Tiered or stepwise assessments are recommended that first clarify what adverse effects have occurred and then attempt to identify the responsible contaminants.
Effects of esfenvalerate on aquatic organisms in littoral enclosures
Authors: Lozano Stephen J. , O'Halloran Susan L. , Sargent Kenneth W. , Brazner John C. 
Published: March 2010

Abstract
The effects of esfenvalerate [(S)-α-cyano-3-phenoxybenzyl(S)-2-(4-chlorophenyl)-3-methylbutyrate] on plant and animal communities were observed in 12 littoral enclosures (5 × 10 m) in a 2-ha pond near Duluth, Minnesota, at six concentrations (0, 0.01, 0.08, 0.2, 1, and 5 μg/L, nominal) for eight weeks. Esfenvalerate exposures of 1 and 5 μg/L resulted in drastic reductions or elimination of most crustaceans, chironomids, juvenile bluegills (Lepomis macrochirus), and larval cyprinids. Abundance of some copepod and insect genera declined at esfenvalerate concentrations of 0.08 to 0.2 μg/L, and these effects were apparent up to 53 d. Some invertebrate communities were able to recover by day 25 in enclosures containing concentrations of ≤0.2 μg/L esfenvalerate.
Use of outdoor artificial streams to determine threshold toxicity concentrations for a petrochemical effluent
Authors: Crossland N.O. , Mitchell G.C. , Dorn P.B. 
Published: March 2010

Abstract
A system of six partly flow-through, partly recirculating, streams was constructed outdoors from stainless steel and divided into pool and riffle sections to closely simulate a natural stream environment. The organic fraction extracted from the effluent of a petrochemical manufacturing plant was identified as a mixture of chlorinated ethers. The effluent extract was applied to three of the streams to maintain nominal concentrations of chlorinated ethers of 0.5, 1.0, or 2.0 mg/L for a period of 28 d. A fourth stream was treated with 0.25 mg/L for 21 d; this was then increased to 4.0 mg/L for a further 7 d. Two streams were untreated and served as controls. There were no detectable effects of the treatments on macroinvertebrate population densities. There was a marked effect on the drift of macroinvertebrates at a concentration of 2.0 mg/L, but there was no effect at lower concentrations. There was an effect on the feeding rates of Gammarus pulex at concentrations of 1.0, 2.0, and 4.0 mg/L, but there were no effects at concentrations of 0.25 and 0.5 mg/L. The results of this experiment were compared with those obtained in 7-d, single-species toxicity tests. On the basis of the toxicity tests, the no-observed-effect concentration (NOEC) for the most sensitive biological response—growth of Daphnia magna — was 1.0 mg/L. On the basis of the field test, the NOEC for the most sensitive biological response — feeding rate of G. pulex — was 0.5 mg/L.
Rapid establishment of test conditions and trophic-level interactions in 0.04-hectare earthen pond mesocosms
Authors: Howick Gregory L. , Giddings Jeffrey M. , Denoyelles Frank , Ferrington Leonard C. , Kettle W. Dean , Baker Debra 
Published: March 2010

Abstract
A mesocosm study of pesticide effects was conducted between November 1987 and November 1988 using 0 04-ha earthen ponds The bottoms of the ponds were covered with sediments from an old farm pond, filled with aged reservoir water, and stocked with fifty 11- to 17-cm blue-gill sunfish Importing mature communities rapidly produced taxonomically rich ecosystems Coefficients of variance among ponds for taxonomic richness and population densities were modest (typically 10–30%) and usually inversely related to abundance Unchecked bluegill reproduction resulted in expected effects on lower trophic levels Crustacean zooplankton were nearly eliminated, which led to poor growth of the juvenile bluegill Phytoplankton densities appeared to increase as grazing pressure from zooplankton was reduced Insect emergence was not obviously impacted by fish predation Potential indirect effects on fish, such as growth impairment caused by pesticide induced reduction of food supply, could be obscured if zooplankton were nearly eliminated by over-predation This suggests a need to control bluegill reproduction to achieve a more balanced ecosystem
Occurrence and fate of tributyl- and triphenyltin compounds in western mediterranean coastal enclosures
Authors: Tolosa I. , Bayona J. M. , Albaigés J. , Merlini L. , De Bertrand N. 
Published: March 2010

Abstract
Tributyltin (TBT) and its degradation products, mono- (MBT) and dibutyltin (DBT) have been determined in the dissolved and particulate phases of seawater, sediments, and biota collected in some representative open and enclosed coastal areas of the western Mediterranean Sea. The highest levels were found in sediments and seawater of dry docks and marinas, closely related with boating activity and clearly decreasing according to the distance from the point sources. Triphenyl- (TPhT) and diphenyltin (DPhT) were also identified for the first time in seawater and sediments collected in marinas, exhibiting concentrations similar to TBT. Concentration ratios between TBT/DBT and TPhT/DPhT in each environmental compartment as well as the field partition coefficients (Kd, K′d, and Kb) of the different tin species point out the complexity of organotin speciation, because accumulation and degradation processes occur at different rates, depending on the environmental compartment.
Investigations of a neurotoxic oscillatorialean strain (Cyanophyceae) and its toxin. Isolation and characterization of homoanatoxin-a
Authors: Skulberg Olav M. , Skulberg Randi , Carmichael Wayne W. , Andersen Rolf A. , Matsunaga Shigeki , Moore Richard E. 
Published: March 2010

Abstract
A neurotoxic cyanophyte (Oscillatoriales) was characterized biologically and chemically with respect to toxic properties. The organism, identified as Oscillatoria formosa (Phormidium formosum [Bory ex Gom.] comb.n. Anagnostidis et Komárek), was isolated and brought to pure culture. The dried biomass used in these investigations was grown from the strain NIVA-CYA 92 in semicontinuous culture, giving yields of about 400 mg/d dry weight of the organism, and the toxic component was extracted and separated on C18 Bond Elut® cartridges followed by HPLC purification. The purified toxin was used for structure determination by low-resolution MS and nuclear magnetic resonance. The toxin is a secondary amine alkaloid identified as methylene-anatoxin-a and was therefore named homoanatoxin-a. It is a potent neuromuscular blocking agent (LD50 [i.p., mouse] 250 μg/kg). Toxicosis in the lethal dose range leads to severe body paralysis, convulsions, and death by respiratory arrest in 7 to 12 min. Experiments with rat phrenic nerve-hemidiaphragm preparations demonstrated that the physiological effects of homoanatoxin-a are related to those observed for d-tubocurarine.
Copper accumulation on gills of fathead minnows: Influence of water hardness, complexation and pH of the gill micro-environment
Authors: Playle Richard C. , Gensemer Robert W. , Dixon D. George 
Published: March 2010

Abstract
Water pH in the gill micro-environment of adult fathead minnows (Pimephales promelas Rafinesque) was measured by means of opercular catheters and latex masks. Synthetic soft water of pH &lt;5.7 was rendered more basic as it passed over the gills and water of pH &gt;5.7 was made more acidic, so that pH of the gill micro-environment stayed at approximately 5.4 to 5.9 over the inspired pH range 4.8 to 6.3. Copper would therefore be &gt;99% Cu2+ at the gills. To measure Cu accumulation on gills, the target organ for Cu toxicity, adult fathead minnows were exposed for 2 to 3 h to 16 μg/L Cu in synthetic soft water (Ca2+ and Na+ approximately 50 μeq/L) at pH 4.8 and 6.3. Gill Cu concentrations were about 1.7 μg Cu/g wet tissue for the inspired pH 4.8 and 6.3 exposures. Added Ca2+ of 2,100 or 4,000 μeq/L reduced gill Cu accumulation during exposures at pH 4.8 but not at pH 6.3. EDTA eliminated Cu deposition at both pH 4.8 and pH 6.3 when equimolar with Cu, but reduced Cu deposition (by 50%) when half equimolar only in the pH 4.8 exposures. These results can be explained by Ca2+ and H+ competition with Cu for gill binding sites and by complexation of Cu by EDTA. Added CaCO3 did not reduce gill Cu, although both competition by Ca2+ and complexation by CO2−3 were expected. Water chemistry calculations suggested that because little CO2−3 is available at pH &lt; 7, CO2−3 from CaCO3 is less likely to affect Cu deposition on fish gills than is Ca2+ from CaCO3.
Comparison of Przm and Gleams computer model predictions with field data for alachlor, metribuzin and norflurazon leaching
Authors: Mueller Thomas C. , Bush Parshall B. , Banks Philip A. , Jones Ronald E. 
Published: March 2010

Abstract
The ability of the pesticide root zone model (PRZM) and groundwater loading effects of agricultural management systems (GLEAMS) model to simulate movement of three herbicides was evaluated with site-specific soil, environmental, and pesticide data. Field studies examined norflurazon movement in a Dothan loamy sand in which cotton (Gossypium hirsutum L.) was grown, and alachlor and metribuzin movement in an Appling sandy loam. Actual herbicide concentrations were always greatest near the soil surface. The PRZM and GLEAMS computer simulation models accurately predicted the total herbicide present in each profile less than 20 d after application. The models overestimated herbicide movement into the soil profile in later simulations. The model predictions generally agreed with the relative location of alachlor and metribuzin in simulations less than 7 d after herbicide applications, but simulations beyond 7 d after herbicide application deviated from actual concentrations. PRZM accurately predicted that most of the applied norflurazon would remain close to the soil surface 84 d after herbicide application, whereas GLEAMS inaccurately predicted that norflurazon would be located throughout the soil profile, although the predicted depth to the limit of detection by both models was accurate.
Partial rapid metabolism of 1,2-dichloroethane by Methylosinus trichosporium OB-3b
Authors: Riebeth D. M. , Belser N. O. , Castro C. E. 
Published: March 2010

Abstract
Resting cell suspensions of the soil methylotroph Methylosinus trichosporium OB-3b rapidly dehalogenate ethylene dichloride, but the process stops after one halogen is removed. Work with 14C- and 13C-labeled 1,2-dichloroethane shows that the biodehalogenation entails a direct hydrox-ylation of one of the CCl bonds to produce chloroethanol. The latter is rapidly oxidized to chloroacetic acid. The organism does not metabolize this acid on the time scale of these experiments.
Comparison of growth and mortality in juvenile sand dollars (Dendraster excentricus) as indicators of contaminated marine sediments
Authors: Casillas Ed , Weber Doug , Haley Craig , Sol Sean 
Published: March 2010

Abstract
A bioassay system involving exposure of juvenile sand dollars (Dendraster excentricus) to contaminated sediments from Puget Sound, Washington, was evaluated. In these bioassays, juvenile sand dollars were exposed to serially diluted sediments from three urban areas with different types and levels of contamination. Physical and biochemical measures of growth (i.e., length or diameter, DNA content, and protein content) were then evaluated for sensitivity and concentration responsiveness to a chemical gradient and compared with mortality as biological indicators of toxicant effects in sediments. Growth measurements appeared to be more sensitive indicators of contaminant exposure than mortality. Sediment mixtures with the highest proportions of contaminants were generally lethal to these organisms, but at lower sediment concentrations, where significant mortality did not occur, significant reductions in growth were observed. The results suggest that measurement of growth, either morphometrically or biochemically, in conjunction with mortality can provide better discrimination for assessing toxicity in sediment bioassay systems. Also, because impaired growth is a sublethal effect of contaminant exposure, it may be a useful indicator for assessing the long-term (chronic) effects of exposure to contaminants on marine organisms.