bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metal-supplemented diets alter carbohydrate levels in tissue and hemolymph of gypsy moth larvae (Lymantria Dispar, lymantriidae, lepidoptera)
Authors: Ortel Johanna 
Published: March 2010

Abstract
Larvae of Lymantria dispar were exposed to two concentrations each of Cd, Pb, Cu, and Zn from hatching to day 3 of the fourth instar. The metals were applied via artificial diet (wheat germ diet); two control groups were reared on either an uncontaminated artificial diet (C) or on a natural diet (oak leaves, EF). High-pressure liquid chromatography (HPLC) was employed to analyze the hemolymph carbohydrates, whereas body glycogen and glucose were determined enzymatically. The results were analyzed with respect to diet-specific differences (oak leaves versus wheat germ diet) and metal exposure compared with the uncontaminated artificial diet. Hemolymph trehalose levels were higher in oak leaf-reared individuals than in those fed on the wheat germ diet (p &lt; 0.01), whereas the opposite applied to the body glycogen and free glucose levels (p &lt; 0.01). The average trehalose value of the control (C) (4.3 mg/ml) was reduced by metal contamination, dependent on both the metal itself and the concentration (Cd, Cu, Zn; 1.4–3.3 mg/ml). Sorbitol was not detected in the hemolymph of EF specimens, whereas it occurred in all artificial diet-fed groups. Metal- and dose-dependent differences in the hemolymph sorbitol levels were observed in the treatment groups, but not in the controls. Glycogen content increased in the low concentration of Cd, Pb, and Cu, whereas a decrease was observed for the low Cd and both Zn concentrations. Tissue free glucose was enhanced only in three of the metal groups. Generally, fresh and dry weights of larvae were reduced in all groups except the high Cu-contaminated one. The results may indicate that mass outbreaks of an important forest pest insect like L. dispar may be facilitated in metal-contaminated areas because parasitization success of antagonistic species may decline due to deterioration of nourishment within the metal-stressed host.
Uptake and depuration of polycyclic aromatic hydrocarbons from sediment by the zebrafish (Brachydanio Rerio)
Authors: Djomo J. E. , Garrigues P. , Narbonne J. F. 
Published: March 2010

Abstract
Zebrafish (Brachydanio rerio) were exposed for 30 d to individual 14C-labeled polycyclic aromatic hydrocarbons (PAHs) (anthracene, phenanthrene, pyrene, or benzo[a]pyrene) adsorbed on sediment. The uptake and depuration rate constants were measured. Rate of radioactivity release was measured under both contaminated (experiment 1) and clean (experiment 2) conditions. The results confirm that uptake and depuration rate constants were strongly related to physicochemical properties. However, the uptake from the water compartment was rapidly decreased in our microcosm system (–83% for anthracene and phenanthrene, –71% for pyrene, and –59% for benzo[a]pyrene within the first 2 d). For depuration in clean water, the half-lives of radioactivity loss from whole body were 63, 97, 115, and 138 h for anthracene, phenanthrene, pyrene, and benzo[a]pyrene, respectively, and were positively correlated with log Kow. In experiment 1 after 10 d, the remaining PAH concentrations were only about 16% of the maximum concentrations measured at time 24 h for anthracene, 12% for phenanthrene, 30% for pyrene, and 46% for benzo[a]pyrene. Kow appears to be a determining factor for partitioning constants for sorption to sediment, uptake, and release in aquatic organisms.
Life-stage-specific toxicity of sediment-associated chlorpyrifos to a marine, infaunal copepod
Authors: Green Andrew S. , Chandler Thomas G. , Piegorsch Walter W. 
Published: March 2010

Abstract
The life-stage-specific acute toxicity of sediment-associated chlorpyrifos to the marine, infaunal copepod, Amphiascus tenuiremis, was assessed. Chlorpyrifos is a common-use, high Kow, organophosphate pesticide. Duplicate 96-h tests were conducted with each major life stage of the copepod (adult, copepodite, and nauplius) exposed to sediments spiked with chlorpyrifos. Calculated median lethal concentrations (LC50s) were 66, 74, and 40 μg chlorpyrifos per kilogram sediment for the adult, copepodite, and nauplius stages, respectively. Analysis of covariance and logistical regression analysis on the mortality data revealed significant (α = 0.05) sensitivity differences for the life stages. The nauplius stage was significantly more sensitive than either the adult or copepodite stages. However, the copepodite stage showed no significant sensitivity difference versus the adult stage. The lowest-observed-effect concentrations (LOECs) also showed these relationships, with the naupliar LOEC being almost three times lower than that of either the adult or copepodite stages. A predicted sediment quality criterion (SQC) based on the equilibrium partitioning theory (EqPT) for chlorpyrifos was calculated to be 38 μg chlorpyrifos per kilogram sediment. This calculated criterion, supposedly protective of most sediment-dwelling invertebrates, was only 2 μg/kg lower than the LC50 for the nauplius life stage and far above the LOEC. An EqPT-derived SQC for chlorpyrifos clearly would not be protective of this meiobenthic copepod.
Potential impact of low levels of chlorsulfuron and other herbicides on growth and yield of nontarget plants
Authors: Fletcher John S. , Pfleeger Thomas G. , Ratsch Hilman C. , Hayes Robert 
Published: March 2010

Abstract
The influence of low application rates of chlorsulfuron on the growth and reproduction of four taxonomically diverse plant species (canola, smartweed, soybean, and sunflower) were examined. Exposures examined ranged from 1 × 10−3 to 8 × 10−3 of the recommended field rates for cereal crops and were approximately 1,000 times less than the highest exposure recommended by the U.S. Environmental Protection Agency. Each species received a single application at one of three different stages of reproductive development. Effects were determined by measuring the height and yield of mature plants. The comparative effects of four different herbicides (atrazine, chlorsulfuron, glyphosate, and 2,4-D) were determined in the same manner by exposing each test species to a single low dose at one of three critical stages of reproductive development.
Chlorsulfuron reduced the yield of all plants tested, with the amount of reduction depending on the time and rate of application. Most noteworthy was its influence on canola and soybean, in which at critical stages in development, applications of 9.2 × 10−5 and 1.8 × 10−4 kg/ha, respectively, reduced seed yields (dry wt) to 8 and 1% of those of controls without causing a significant change in vegetative growth. These low application rates are within the range of reported herbicide drift levels and suggest that chlorsulfuron may cause severe reduction in the yields of some nontarget crops if they are subjected to exposure at critical stages of development. Application of other herbicides at comparable rates and stages of plant development had no influence on either canola or soybean.
Long-term toxicity of five polycyclic aromatic hydrocarbons for the terrestrial isopods Oniscus Asellus and Porcellio Scaber
Authors: Van Brummelen Timco C. , Van Gestel Cornelis A. M. , Verweij Rudo A. 
Published: March 2010

Abstract
Polycyclic aromatic hydrocarbons (PAH) are a common component of soil pollution, yet little is known of the ecotoxicological risks these compounds may pose to life in soil. This article reports the ecotoxicity of five PAHs for two terrestrial isopod species. Isopods were exposed to food contaminated with four different concentrations of either fluorene, phenanthrene, fluoranthene (up to 4 μmol/g), benz[a]anthracene, or benzo[a]pyrene (up to 1.25 μmol/g). Exposure of Porcellio scaber lasted 16 weeks, and no adverse effects on survival, growth, or total protein (only females tested) were observed in any of the treatments. A small but significant reduction in growth of Oniscus asellus was observed at 47 weeks of exposure to 0.125 μmol benz[a]anthraceneṁg−1 dry weight and 1.25 μmol fluoreneṁg−1 dry weight and higher concentrations. A significant stimulation of the reproduction of O. asellus was observed in some of the phenanthrene, fluoranthene, benz[a]anthracene, and benzo[a]pyrene treatments; a larger proportion of the females were gravid, which resulted in a higher number of juveniles per female. Exposure did not significantly affect brood size, weight of the mother after release of the juveniles, or the survival of the juveniles upon starvation. Total protein content of females was significantly reduced at 0.4 μmol fluorene g−1 dry weight and higher concentrations. Growth and protein content of isopods is likely to be affected by PAH exposure only at highly contaminated sites. The ecological consequences of stimulated reproduction and possible DNA damage are poorly understood and require further attention because soil invertebrates may be exposed to PAHs over many generations.
Comparison of acute toxicity of process chemicals used in the oil refinery industry, tested with the diatom Chaetoceros Gracilis, the flagellate Isochrysis Galbana, and the zebra fish, Brachydanio Rerio
Authors: Roseth Svein , Edvardsson Trym , Botten Merete Tone , Fuglestad Jon , Fonnum Frode , Stenersen Jørgen 
Published: March 2010

Abstract
Chemicals under the trade names Nalco 537-DA, Nalco 625, Nalco 7607, Nalco 5165, Ivamin, and technical monoethanolamine are used extensively in the oil refinery industry. Aquatic toxicity tests were conducted using zebra fish fry (Brachydanio rerio) and the unicellular algae Isochrysis galbana (a flagellate) and Chaetoceros gracilis (a diatom). Inhibition of cell division, chlorophyll content, and 14CO2 uptake in the algae were sensitive end points. The effective concentrations (EC50s) of growth inhibition were 0.1 mg/L (Ivamin; I. galbana), 0.8 mg/L (Nalco 7607; I. galbana), 6 mg/L (Nalco 625; I. galbana), 10 mg/L (Nalco 5165; C. gracilis), and 15 mg/L (Nalco 537-DA; C. gracilis). The lethal concentrations (LC50s) (96 h) toward zebra fish fry was 1 mg/L for Nalco 7607, 6.5 mg/L for Nalco 537-DA, 7.1 mg/L for Nalco 625, and 20 mg/L for Ivamin 803. Monoethanolamine had an LC50 higher than 5,000 mg/L. Nalco 5165 was not tested on fish fry. The heartbeat frequency of fish embryos was reduced by 2.5 mg/L Nalco 537-DA, but this was an insensitive end point for the other chemicals.
Sediment quality assessment studies of Tampa bay, Florida
Authors: Carr Scott R. , Chapman Duane C. , Long Edward R. , Windom Herbert L. , Thursby Glen , Sloane Gail M. , Wolfe Douglas A. 
Published: March 2010

Abstract
A survey of the toxicity of sediments throughout the Tampa Bay estuary was performed as part of the National Oceanic and Atmospheric Administration's National Status and Trends Program. The objectives of the survey were to determine the spatial extent and severity of toxicity and to identify relationships between chemical contamination and toxicity. Three independent toxicity tests were performed: a 10-d amphipod survival test of the whole sediments with Ampelisca abdita, a sea urchin fertilization test of sediment pore water with Arbacia punctulata, and a 5-min Microtox® bioluminescence test with solvent extracts of the sediments. Seventy-three percent of the 165 undiluted sediment pore-water samples were significantly toxic relative to reference samples with the sea urchin fertilization test. In contrast, only 2% of the 165 samples were significantly toxic in the amphipod tests. The causes of toxicity were not determined. However, concentrations of numerous trace metals, pesticides, polychlorinated biphenyl (PCB) congeners, polycyclic aromatic hydrocarbons (PAHs), and ammonia were highly correlated with pore-water toxicity. Concentrations of many substances, especially total dichlorodiphenyltrichloroethanes (DDTs), endrin, total PCBs, certain PAHs, lead, and zinc, occurred at concentrations in the toxic samples that equaled or exceeded concentrations that have been previously associated with sediment toxicity.
Implications of defining test acceptability in terms of control-group survival in two-group survival studies
Authors: Bailer John A. , Oris James T. 
Published: March 2010

Abstract
Tests used to screen for toxic responses often involve the comparison of samples from a putatively contaminated site with a clean reference site. If attention is focused on mortality, then the difference in proportionate mortality/survival in the two groups serves as the basis of statistical inference. As a precursor to conducting such studies, criteria for judging test acceptability, including the minimum level of control survivorship and the number of organisms to be put on test, must be determined. In this article, we review the standard statistical methodology for calculating sample size requirements for two-group comparisons of proportions to highlight the effect of defining test acceptability in terms of survival in the control group. For a fixed level of power, false-positive (type I) error rate, and effect size, we show that lower control-group survival implies the need to place more organisms on test.
Validation of a short-term toxicity test endpoint by comparison with longer-term effects on larval red abalone Haliotis rufescens
Authors: Conroy Patrick T. , Hunt John W. , Anderson Brian S. 
Published: March 2010

Abstract
Experiments were conducted to compare a short-term 48-h aquatic toxicity test endpoint of abnormal larval shell development with other, more clearly adverse effects. In similar experiments conducted with two different toxicants, zinc sulfate and bleached-kraft mill effluent, red abalone (Haliotis rufescens) embryos were simultaneously exposed to identical dilution series and incubated for three different exposure periods: 48 h, 48 h followed by an 8-d recovery period in clean seawater, and 10 d of continuous exposure. Abnormal larval shell development was assessed in the 48-h short-term tests, and inhibition of metamorphosis was assessed in the exposure-recovery and continuous exposure experiments. For the zinc experiments, the median effective concentration (EC50) values for the 48-h exposure, the exposure-recovery experiment, and the continuous exposure experiment were 40, 34, and 32 μg/L zinc, respectively. For the bleached-kraft mill effluent experiments, the EC50 values were 0.98, 0.76, and 0.69% effluent, respectively. Results indicate that toxicant concentrations causing abnormal larval shell development also inhibit metamorphosis and that larvae exposed to toxicant concentrations which inhibit larval shell development do not recover to metamorphose when transferred to clean seawater. None of the successfully metamorphosed postlarvae had deformed larval shells, indicating that shell deformity precludes survival past the planktonic stage. A longer (15-d) experiment allowed measurement of postlarval shell length in exposed postmetamorphic abalone. Insignificant differences in postlarval shell length indicated that the timing of larval metamorphosis was similar regardless of toxicant exposure and that the effects of the toxicant was to inhibit rather than to delay metamorphosis.
Integrating chemical and biological remediation of atrazine and S-triazine-containing pesticide wastes
Authors: Arnold Scott M. , Hickey William J. , Harris Robin F. , Talaat Rasmy E. 
Published: March 2010

Abstract
Fenton's reagent (FR) and the catabolic activity of Rhodococcus corallinus and Pseudomonas sp. strain D were combined to detoxify s-triazines in pure solutions and mixed wastes. In solutions containing only atrazine, complete atrazine decomposition was accomplished with 2.69 mM FR. But FR treatment was not complete in a remediation context because stable, potentially carcinogenic chlorinated products accumulated as end products. Rhodococcus corallinus degraded these products in ≤10 min and produced 47% 14CO2 from [2,4,6-14C]atrazine in 7 d. Combining R. corallinus with Pseudomonas sp. strain D increased 14CO2 production to 73%. When applied to a pesticide rinse water containing atrazine, cyanazine, alachlor, metolachlor, and EPTC, ≥99% of the pesticides were degraded with 12.2 mM FR. Subsequent treatment with R. corallinus and Pseudomonas sp. strain D degraded all chlorinated s-triazine intermediates and released 70% 14CO2 from a [2,4,6-14C]atrazine tracer in 10 d. Use of R. corallinus obviated the need for additional chemical pretreatment, e.g., acidification or base hydrolysis, used in previous studies prior to microbial incubations. Thus, this method has potential as an on-site treatment for pesticide rinse water.
Aqueous solubility of permethylsiloxanes (silicones)
Authors: Varaprath Sudarsanan , Frye Cecil L. , Hamelink Jerry 
Published: March 2010

Abstract
The aqueous solubility of several low mlecular weight linear, cyclic, and branched permethylsiloxanes was determined at room temperature. A method for preparing molecularly dispersed, colloid-free saturated aqueous solutions is described. Solubilities, decreasing with increased molecular weights, ranged downward from one part per million to mere parts per trillion. The cyclic oligomers were slightly more soluble than their linear analogues. While the effect of branching was mixed, polar groups such as phenyl and hydroxyl moities sharply increased aqueous solubility. Semilog plots of the solubility/molecular weight yielded linear regressions, the extrapolation of which indicate the absence of any environmentally relevant water solubility (&lt; 1 ppt) for the conventional higher molecular weight polydimethylsiloxanes of commerce.
Time-dependent isotherm shape of organic compounds in soil organic matter: Implications for sorption mechanism
Authors: Xing Baoshan , Pignatello Joseph J. 
Published: March 2010

Abstract
Batch 1-, 30-, and 180-d sorption isotherms were constructed for 1,3-dichlorobenzene, 2,4-dichlorophenol, and metolachlor (2-chloro-N-[2-ethyl-6-methylphenyl]-N-[2-methoxy-1-methylethyl] acetamide) in aqueous suspension of a fine sandy loam soil (3% organic matter) and a peat soil (93% organic matter) at sorptive concentrations ranging over three to five orders of magnitude. The isotherms were fitted to the Freundlich model, S = KCN, where S and C are the sorbed and solution-phase concentrations and K and N are constants. Both K and N were time-dependent. K increased by as much as 2.7-fold beyond the 1-d period. N was less than unity in all cases and decreased with increasing sorption. Also, the isotherms were operationally separated into a “fast” fraction (amount sorbed after 1 d) and a “slow” fraction (amount sorbed thereafter). Ns was significantly smaller than Nf in all systems tested. The results show that partitioning in soil organic matter (SOM) is appreciably less ideal for the slow fraction. It is concluded that SOM has both partition and adsorption domains analogous to the dual-mode sorption model of glassy polymers. The adsorption component is more prominent for the slow fraction, indicating that the adsorption sites are internal to the SOM matrix and unevenly distributed with respect to access by sorbing molecules. Sorption by these natural materials was compared with sorption by polyvinylchloride, a glassy polymer that exhibits dual-mode sorption. That system gave nonlinear isotherms with an N that was invariant with time, consistent with its nature as a homogeneous polymer having evenly distributed adsorption sites.
Mercury contamination and population-level responses in chironomids: Can allozyme polymorphism indicate exposure?
Authors: Woodward Lee Ann , Mulvey Margaret , Newman Michael C. 
Published: March 2010

Abstract
Allozyme frequencies of Chironomus plumosus were determined along a gradient of sediment mercury concentrations in a contaminated lake. We examined whether allozyme frequencies could be used to distinguish populations along the gradient or between contaminated and reference sites. No significant correlations were found between allozyme frequencies and contamination, but an overall deficit of heterozygotes (in nine of 13 loci examined) was found at all sites sampled. While toxicant stress could be the cause, a more parsimonious explanation would be sampling over a patchy population structure leading to a heterozygote deficiency (i.e., Wahlund effect). Examination of allozyme frequencies along a transect indicated that the observed deficiency of heterozygote genotypes was due to sampling across some fine-scale substructuring of the populations. The findings of these studies lend a note of caution regarding the use of allozymes to infer population effects of contaminants or their potential use as biomarkers. Studies must define population structure, naturally occurring variation within and among populations, and relevant ecological factors in conjunction with the presence of xenobiotics and their concentrations.
Accumulation of hsp70 in juvenile and adult rainbow trout gill exposed to metal-contaminated water and/or diet
Authors: Williams Jeanne H. , Petersen Nancy S. , Young Patricia A. , Stansbury Mark A. , Farag Aida M. , Bergman Harold L. 
Published: March 2010

Abstract
The accumulation of heat shock cognate (hsc)/heat shock protein (hsp) 70 was measured in gill and liver from juvenile and adult rainbow trout (Oncorhynchus mykiss) exposed to waterborne metals and/or fed a metal-contaminated diet. These experiments are part of a larger study in which physiological responses were documented in adult and juvenile rainbow trout after exposure to food-borne and/or waterborne metals for 21 d. Western blot analyses were used to measure the accumulation of hsp70 and hsc70. Hsc/hsp70 levels were significantly increased in gills of juveniles exposed to metals, in both water and food. The importance of metals in the diet as well as the water was confirmed for the juveniles. Significant increases in hsp/hsc70 could not be demonstrated in the adults.
Teratogenic and genotoxic responses of larval Chironomus salinarius group (diptera: Chironomidae) to contaminated sediment
Authors: Hudson Lori A. , Ciborowski Jan J. H. 
Published: March 2010

Abstract
Chironomids are important indicators of the effects of sediment-bound contaminants. However, cause–effect relationships between contaminant exposure and stress-related indicators other than growth and survival have not been demonstrated. In the laboratory, we conducted 10-d exposures of Chironomus salinarius group Kieffer larvae to mixtures of contaminated (Trenton Channel, Detroit River, MI) sediment diluted with uncontaminated, formulated sediment (sand, sculptor's clay, and potting soil) in ratios of 1:0, 1:1, 1:3, 1:7, 1:15, and 0:1. Larvae were inoculated into either recently mixed sediments or those allowed to age for 7 d. Surviving larvae were examined for mouthpart (mentum) deformities. Giant chromosomes of the salivary glands were examined for reduction in relative nucleolus diameter (RND). Proportions of larvae with mentum deformities and of larvae with reduced RND increased linearly with each doubling of concentration of contaminated sediment. Deformities and RND reduction in individual larvae were independent responses. Incidences of deformities at low contamination doses were much greater for recently mixed sediments than for more aged sediments. Sediment age did not affect incidence of reduced RND except in the most contaminated treatment. Mentum deformities and reduced RND are quantifiable sublethal attributes reflecting stress responses to sediment contamination that can complement more traditional measures (survival and growth) in chironomid sediment bioassays.