bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of aniline and three derivatives on laboratory microecosystems
Authors: Yount J. David , Shannon Lyle J. 
Published: March 2010

Abstract
Generic mixed-flask microcosms were used to evaluate ecosystem responses to aniline and three closely related compounds—2,6-diisopropylaniline, 4-hexyloxyaniline and 2,3,5,6-tetrachloroaniline. Toxicity was determined on both an acute and chronic basis using changes in ecosystem-level variables (pH and dissolved oxygen levels) as indicators of effect. These calculated toxicity values were then compared with reported toxicity data on bacteria, algae, protozoa and Cladocera to evaluate the relative sensitivity of the method. The relative toxicities of the tested compounds were the same in microcosm tests as in the available single-species tests, but the range between the most and least toxic as determined by the microcosm test was smaller by an order of magnitude. Aniline was the least toxic, followed, in order of increasing toxicity, by 2,6-diisopropylaniline, 4-hexyloxyaniline and 2,3,5,6-tetrachloroaniline. The minimum effect concentrations determined for these compounds were generally lower than reported literature values, suggesting that the method does not sacrifice sensitivity in providing an integrated picture of ecosystem-level effects.
Dynamics of hydrophobic organic chemical bioconcentration in fish
Authors: Gobas Frank A. P. C. , MacKay Donald 
Published: March 2010

Abstract
A model is presented describing the kinetics of uptake and release of nonmetabolizing organic chemicals by fish from water. The model contains three parameters: a bioconcentration factor which is specific to the chemical (and can be characterized by the octanol/water partition coefficient and fish lipid content), a water-phase resistance term and a lipid-phase resistance term which are specific to the fish. These parameters can be estimated from uptake-clearance experiments. Part of the water-phase resistance term can be attributed to gill ventilation rate as estimated from gill uptake efficiencies and part is an “internal” resistance. Procedures are suggested for scaling these parameters to different fish sizes. The dependence of these resistances, and uptake and clearance rate constants, on chemical hydrophobicity is discussed and quantified.
Effects of chemical structure and exposure on the microbial degradation of polycyclic aromatic hydrocarbons in freshwater and estuarine ecosystems
Authors: Heitkamp Michael A. , Cerniglia Carl E. 
Published: March 2010

Abstract
The microbial mineralization of six polycyclic aromatic hydrocarbons (PAHs), containing two to five fused benzene rings, and hexadecane were investigated in sediment: water microcosms which modeled degradation in two freshwater and one estuarine ecosystem. A ranking of the PAHs by order of mineralization rates along with calculated half-lives (range in weeks) are as follows: naphthalene (2.4-4.4) ≥ hexadecane (2.2-4.2) &gt; phenanthrene (4-18) &gt; 2-methylnaphthalene (14-20) &gt; pyrene (34-&gt;90) ≥ 3-methylcholanthrene (87-&gt;200) ≥ benzo[a]pyrene (200-&gt;300). PAH residues persisted from two to over four times longer in a pristine ecosystem than in an ecosystem chronically exposed to low levels of petroleum hydrocarbons. The mineralization of higher-molecular-weight PAHs (&gt; four rings) totaled 0.2 to 6.5% after 8 wk. Relative differences in PAH mineralization among the ecosystems were related to hexadecane mineralization rates, the occurrence and concentration of aromatic hydrocarbon residues in sediments, and elevated populations of hydrocarbon-degrading microorganisms. Total heterotrophic microbial populations were not good indicators of PAH mineralization rates. Chemical analyses of residues in the microcosms detected the presence of extractable polar metabolites in water and sediments which accounted for 0.1 to 6% of the original PAHs.
Effects of experimental manipulation of environmental factors on phenol mineralization in soil
Authors: Thornton-Manning Janice R. , Jones Daniel D. , Federle Thomas W. 
Published: March 2010

Abstract
The effects of temperature and nitrogen, phosphorus, and carbon enrichments on phenol mineralization were determined in the uppermost and deepest horizons of two contrasting soils. Soil samples were amended with trace levels of 14C-phenol and incubated under various experimental conditions. Mineralization was determined by measuring the production of 14CO2 with time. First-order rate constants (k) and extent of mineralization (PO) were estimated from the resulting data using nonlinear regression. Temperature affected mineralization differently as a function of soil type. While not stimulating mineralization in the upper horizons, nitrogen and phosphorus enrichment resulted in faster and more extensive mineralization in the subsurface horizons. Carbon (cellulose) enrichment had little effect in any soil examined. This study demonstrates the importance of temperature and inorganic nutrient availability in controlling the biodegradation of a model pollutant in surface and subsurface soil. It further illustrates the variability that exists between soil types and between different horizons of the same soil type as to factors capable of influencing biodegradation processes.
Effects of hydrogen fluoride on incorporation and transport of photoassimilates in soybean
Authors: Madkour Samia , Weinstein Leonard H. 
Published: March 2010

Abstract
The effect of hydrogen fluoride (HF) on the translocation and partitioning of 14C between transport and nontransport photoassimilates from source leaves to sink regions was studied. Soybean plants (Glycine max (L.) Merr. cv ‘Hodgson 78’) were fumigated continuously with HF at 0, 1, and 5 μF-m−3 for 8 to 10 d at three stages of development (vegetative, flowering and early fruit set, and pod filling). The second fully expanded trifoliolate leaf of experimental plants was exposed to 14CO2.
In plants exposed to HF, there was an increased retention of 14C-labelled assimilates in foliage (source tissue), accompanied by a reduced export of these compounds to other plant parts (path and sink tissues). There was also a greater incorporation of 14C into nontransport ethanolinsoluble assimilates at the expense of the ethanol-soluble transport assimilates in source leaves. When compared with control plants, exposure to HF also increased the proportion of 14C incorporated into sugars in source leaves accompanied by a decrease in 14C-sugars in sink tissues.
Results suggest that the retention of sugars in source leaves and the reduction in allocation to sink tissue may be a result of the inhibition of the process involved in the export of sugars from the leaf (i.e., phloem loading). An inhibition of phloem loading may result in an accumulation of sugars in the mesophyll cells, which may exhibit feedback inhibition on starch degradation and/or stimulation of starch synthesis.
The relationship of life history attributes to toxicant tolerance in fishes
Authors: Neuhold John M. 
Published: March 2010

Abstract
The relationship between tolerance to toxicants and fish species longevity, maximum weight attained, and fecundity is demonstrated. It is concluded that among species longevity and maximum weight attained is negatively related to tolerance to toxicants, while fecundity is positively related to toxicant tolerance. It is also concluded that mode of action of toxicants is related to longevity and fecundity among species.
Comparison of the EC50s of algal toxicity tests calculated by four methods
Authors: Walsh Gerald E. , Deans Christine H. , McLaughlin Leslie L. 
Published: March 2010

Abstract
EC50s (calculated concentrations that would inhibit growth by 50%) of 21 pesticides in unicellular algal toxicity tests were calculated by straight-line graphical interpolation, moving average interpolation, prohibit analysis, and the binomial method. EC50s of 18 tin compounds were calculated by graphical interpolation, moving average, and probit methods. Results from a total of 187 tests were analyzed. The EC50 values were essentially identical when calculated by each method. Although moving average and probit analyses allow calculation of confidence intervals, there is doubt that they can be used with the quantitative data of algal toxicity tests. In the absence of confidence intervals, only the calculated EC50 is used to express relative toxicity, and straight-line graphical interpolation, a simple and rapid method, may be used in lieu of more complex statistical methods.
Degradation of selected halogenated ethanes in anoxic sediment-water systems
Authors: Jafvert Chad T. , Lee Wolfe N. 
Published: March 2010

Abstract
The degradation of selected halogenated ethanes was studied in anoxic sediment-water suspensions at 1 to 20% sediment concentrations. Batch kinetic experiments were used to quantify decay. Eh measurements of all suspensions were below -100 mV (vs SHE), indicating reduced environmental conditions. Hexachloroethane (HCA), 1,1,2,2-tetrachloroethane (TTCA), 1,2-diiodoethane (DIA) and 1,2-dibromoethane (DBA) were degraded within minutes to days, but 1,2-dichloroethane (DCA) remained in the system through 35 d, at which point the study was ended. The major route of transformation of these compounds in this system was vicinal dehalogenation. Rates of disappearance followed pseudo-first-order kinetics at low reactant concentrations and high sediment concentration. The order of reactivity in the same sediment sample followed the sequence, HCA ⋍ DIA &gt; DBA &gt; TTCA &gt; DCA.
Assessment of contamination of fish by water-soluble fractions of petroleum: A role for bile metabolites
Authors: Hellou Jocelyne , Payne Jerry F. 
Published: March 2010

Abstract
Several conjugated metabolites were found to accumulate in the gall bladder bile of trout (Salmo gairdneri) exposed to No. 2 fuel oil, but no free metabolites could be detected. GC-MS analysis of the major resolved components resulted in the identification of at least eight metabolites, present as alcohols. Single-ion monitoring MS indicated the predominance of a fragment at m/e 152, and 1H-NMR spectroscopy provided information on the average structure of the mixture of hydrolyzed metabolites. The study demonstrated that focusing on specific two- and three-ring conjugated metabolites in the gall bladder bile of fish can provide a simple and rapid investigative tool for the monitoring and assessment of petroleum and fuel oil pollution.
Subcellular distribution and binding of cadmium to metallothionein in tissues of rainbow trout after exposure to 109Cd in water
Authors: Olsson Per-Erik , Hogstrand Christer 
Published: March 2010

Abstract
The uptake and distribution of cadmium in rainbow trout (Salmo gairdneri) was studied after 1 week of exposure to 109Cd in water and after a subsequent 14-week period in clean water. The major target organs, that is, gills, kidney, liver and intestine, were analyzed for 109Cd content and the subcellular distribution of cadmium determined. A successive redistribution of cadmium from the gills and intestine to the liver and kidney was observed. Sephadex G-75 chromatography of the organs revealed that most of the cadmium was found in the metallothionein-containing peak and that the amount of cadmium in this peak increased over time after the exposure. Ion-exchange chromatography on fast protein, polypeptide and polynucleotide liquid chromatography of the metallothionein-containing peaks revealed that 109Cd eluted together with copper and polaro-graphic activity. There was no evidence that other low-molecular-weight cadmium-binding proteins were present in the organs. These results indicate that the metallothionein in rainbow trout binds cadmium after the fish are exposed to the metal in water.
Residues of dimethioate and methomyl on tomato and cabbage in relation to their effect on quality-related properties
Authors: Othman Mohamed A. , Antonious G. F. , Khattab Marium M. , Abdel-All A. , Khamis Awatef E. 
Published: March 2010

Abstract
Dimethoate EC 40% and methomyl 90% WSP were applied under field conditions to follow up the decline of their residues on tomato and cabbage plants. The results indicate that the level of dimethoate and methomyl residues were found to be below tolerance level after 7 and 3 d from application, respectively. Dimethoate and methomyl residues also had significant effects on ascorbic acid contents in tomato fruits after 1 and 7 d for dimethoate, while the effect was after 3 and 10 d for methomyl. Dimethoate also showed significant effects on total soluble solids in tomato fruits presented until 14 d after pesticide application. Both dimethoate and methomyl had significant effect on both iron and magnesium content in tomato fruits and leaves and cabbage leaves during the 14 d.
Bioaccumulation of trace organic contaminants from sediment by baltic clams (Macoma balthica) and soft-shell clams (Mya arenaria)
Authors: Foster Gregory D. , Baksi Sandra M. , Means Jay C. 
Published: March 2010

Abstract
Sediment from Chesapeake Bay was fortified with naphthalene-d8, diphenyl-d10 ether, di-n-octyl phthalate-2,3,4,5-d4, p,p-DDT-d8 and chrysene-d12 to measure the bioaccumulation of sediment-sorbed chemicals by baltic clams (Macoma balthica) and soft-shell clams (Mya arenaria). Macoma bioaccumulated the deuterated chemicals from sediment at measurable rates. Uptake transfer coefficients were derived from bioaccumulation, and for Macoma they ranged from 4.95 × 10−2 h−1 for diphenyl-d10 ether to 1.47 × 10−3 h−1 for chrysene-d12. Transfer coefficients for Macoma were inversely related to the water solubilities of the sorbed chemicals. Mya did not show bioaccumulation of the sediment-sorbed chemicals. Bedded sediments contaminated with trace organic chemicals may be a relevant source of exposure to toxicants in estuarine habitats for depositfeeding bivalves.
Evaluation of the developmental toxicity of metal-contaminated sediments using short-term fathead minnow and frog embryo-larval assays
Authors: Stebler Elaine F. , Burks Sterling L. , Bantle John A. , Dawson Douglas A. 
Published: March 2010

Abstract
The effects of metal-contaminated sediment extracts and a reference toxicant (zinc sulfate) were determined by examining the developmental morphology, growth and mortality of exposed fathead minnow (Pimephales promelas) and frog (Xenopus laevis) embryos. Sediments from two contaminated stream sites were extracted with reconstituted culture water at various pH values for 24 h. Developmental toxicity tests were performed using the frog embryo teratogenesis assay-Xenopus (FETAX) protocol. The results suggest that Zn was the major developmental toxicant in the sediment extracts. The measured Zn concentration in the sediment extracts that caused malformation in 50% of the fish embryos (EC50) was 0.5 to 1.4 mg/L (normalized to 100 mg/L hardness). EC50 values for the reference toxicant tests were 0.6 and 0.8 mg/L Zn. The frog embryo EC50 for the extracts ranged from 2.2 to 3.6 mg/L Zn and was 3.6 mg/L Zn in the reference toxicant test. In 67% of the tests, malformation was a more sensitive endpoint than growth inhibition. Mortality was the least sensitive endpoint, that is, the LC50s in the reference toxicant tests were 3.6 mg/L Zn for the fathead minnow and 34.5 mg/L for the frog. The extraction procedure may be useful for determining potential toxicity in the event metals are leached from aquatic sediments by dredging or acidification.
Acute and chronic effects of tributyltin on a chesapeake bay copepod
Authors: Hall Lenwood W. , Bushong Steven J. , Hall W. Scott , Johnson W. Edward 
Published: March 2010

Abstract
One 72-h acute and two 13-d chronic flow-through tributyltin (TBT) toxicity experiments were conducted with the estuarine zooplankter Eurytemora affinis. The 48-h and 72-h LC50s were 2.2 and 0.6 μg/L TBT, respectively, based on measured concentrations. TBT concentrations of 100 ng/L significantly reduced the survival of neonates (young) after 6 d of exposure in the first chronic experiment. Significant adverse effects were not reported at TBT concentrations ranging from 12.5 to 100 ng/L in the second chronic test. However, a significant adverse effect was noted at 200 ng/L in that test. TBT concentrations reported in various marina areas of the northern Chesapeake Bay exceed toxic concentrations found for E. affinis in these laboratory studies.
Toxicity and bioconcentration of 2,3,7,8-tetrachlorodibenzodioxin and 2,3,7,8-tetrachlorodibenzofuran in rainbow trout
Authors: Mehrle Paul M. , Buckler Denny R. , Little Edward E. , Smith Larry M. , Petty Jim D. , Peterman Paul H. , Stalling David L. , De Graeve G. M. , Coyle James J. , Adams William J. 
Published: March 2010

Abstract
Among the most toxic isomers of polychlorinated dibenzodioxins and polychlorinated dibenzofurans, two groups of toxic aromatic compounds, are 2,3,7,8-tetrachlorodibenzodioxin (TCDD) and 2,3,7,8-tetrachlorodibenzofuran (TCDF). We examined the chronic toxicity of these compounds to rainbow trout (Salmo gairdneri). The fish (0.38 ± 0.09 g) were continuously exposed in an intermittent-flow proportional diluter for 28 d to 0, 38, 79, 176, 382, and 789 pg TCDD/L (parts per quadrillion) or to 0, 0.41, 0.90, 1.79, 3.93, and 8.78 ng TCDF/L (parts per trillion); exposures to each chemical were followed by a 28-d depuration phase. TCDD had significant effects on survival, growth, and behavior during the exposure and depuration phases. The no observed effect concentration was lower than the lowest exposure concentration of 38 pg/L. The average measured BCF at 28 days was 26,707. The estimated bioconcentration factor at steady-state equilibrium was 39,000 in the lowest exposure concentration where fish were least affected. TCDF, like TCDD, induced similar effects on survival, growth and behavior. The no observed effect concentration, based on survival, was 1.79 ng/L; that based on growth was 0.41 ng/L. The measured bioconcentration factor was 6,049 in fish exposed to 0.41 ng/L, and 2,455 in fish exposed to 3.93 ng/L for 28 d.
Effects of krenite® brush control agent (fosamine ammonium) on embryonic development in mallards and bobwhite
Authors: Hoffman David J. 
Published: March 2010

Abstract
Fosamine ammonium (Krenite®) is a highly water-soluble carbamoylphosphonate herbicide used to control woody brush. It has been reported to be teratogenic to avian embryos following spray application of the eggs. The embryotoxic and teratogenic potential of Krenite was examined in mallards (Anas platyrhynchos) and bobwhite (Colinus virginianus). At 96 h of development, eggs were briefly immersed in distilled water or in Krenite formulation in distilled water at concentrations of 1.5, 6.5, or 30% fosamine ammonium. At 6.5% active ingredient (a.i.), Krenite reduced hatching success in bobwhite and mallards to 85 and 33% of that in the distilled-water controls. At 30% a.i., Krenite caused 95 to 100% mortality in both species by the time of hatching. Early embryonic growth was impaired by 30% Krenite in both species. There was no evidence of teratogenesis of the axial skeleton, as reported previously in chickens and Japanese quail (Coturnix japonica). Most abnormal embryos had severe edema and some stunting. Mallard hatchlings from the 1.5 and 6.5% Krenite groups weighed significantly less than controls and had lower plasma alanine aminotransferase and aspartate aminotransferase activities, with elevated plasma glucose and cholesterol concentrations. Brain acetylcholinesterase activity was unaffected by Krenite in embryos and hatchlings.
Preparation of aqueous solutions of sparingly soluble organic substances: I. Single component systems
Authors: Billington James W. , Huang Guo-Lan , Szeto Foon , Shiu Wan Ying , Mackay Donald 
Published: March 2010

Abstract
The mass transfer theory underlying the dissolution of sparingly soluble hydrophobic organic chemicals in water is reviewed. It is shown that the preferred method of preparing saturated solutions of such chemicals for physical-chemical or bioassay purposes is by use of the generator column technique, in which water flows through a length of high-surface-area packing coated with the test chemical. The use of shake-flask or batch contacting systems is shown to have inherent disadvantages. A method of calculating the approach to saturation is presented. Solubility data are reported for 13 polycyclic aromatic hydrocarbons, three of which have not been previously reported, and for 10 polychlorinated biphenyl congeners.
Avoidance of brass powder-contaminated soil by the earthworm, lumbricus terrestris
Authors: Wentsel Randall S. , Guelta Mark A. 
Published: March 2010

Abstract
Tests of the avoidance of brass powder (70% Cu, 30% Zn) contaminated soils by the earthworm Lumbricus terrestris at concentrations ranging from 0 to 200 μg/g were conducted. Avoidance was significant (p &lt; 0.001) at brass concentrations as low as 38 μg/g. Avoidance was found to be a more sensitive indicator of the impact of brass powder on the worms than sublethal effects measured by weight loss.
Reactivity of the carbonate radical with aniline derivatives
Authors: Larson Richard A. , Zepp Richard G. 
Published: March 2010

Abstract
Carbonate radicals generated by the photolysis of H2O2 at 313 nm in aqueous sodium bicarbonate (pH 8.3) or carbonate (pH 11.6) solution reacted with substituted aromatic amine derivatives. Particularly fast reactions (second-order rate constants of 5 × 108 to 2 × 109) were observed with anilines bearing electron-donating substituents, either on the ring or at the nitrogen atom. The results suggest that carbonate radicals may play a significant role in the removal of some aromatic amines from the aquatic environment, particularly in carbonate-rich waters.
Effects of acute exposure to acidified water on the behavioral response of fathead minnows, Pimephales promelas, to alarm substance (schreckstoff)
Authors: Smith R. J. F. , Lawrence B. J. 
Published: March 2010

Abstract
Fathead minnows, Pimephales promelas, exposed to acidified water (pH = 5.0) for 72 h continued to respond normally to the alarm substance (Schreckstoff) contained in water extracts of conspecific skin. This result contrasts with an earlier finding that some behavioral responses to chemical feeding stimuli are lost at relatively high pH levels (pH = 6.0). In combination, the two sets of results indicate that different stimulus/response systems have different thresholds for interference by acidification.
Procedure for evaluating the potential ability of birds to avoid chemically contaminated food
Authors: Bennett Richard S. , Schafer Daniel W. 
Published: March 2010

Abstract
A procedure for evaluating the potential ability of birds to avoid chemically contaminated food is described. The discrimination threshold is defined as the dietary concentration above which test animals will decrease the proportion of treated food they consume if untreated alternative foods are available. Two-phase regression analysis is used to calculate the discrimination threshold, 95% confidence interval and the goodness of fit of the model. An index to evaluate the relative potentials for food avoidance behavior between chemicals is described.