bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photolysis of aryl ketones with varying vapor pressures on soil
Authors: Kieatiwong Somchai , Miller Glenn C. 
Published: March 2010

Abstract
The photolysis of a series of aryl ketones on air-dried soil surfaces was examined to establish whether vapor transport has an effect on the rate and extent of photolysis. If vapor transport were significant on light-exposed soils, then differences in the observed photolysis rate profiles would be expected, with the compounds having higher vapor pressures exhibiting the greatest photolysis. The aryl ketones, including hexanophenone, octanophenone, dodecanophenone, hexadecanophenone, and octadecanophenone, had nearly identical photolysis rates in solution exposed to sunlamps (Λmax 310 nm). The vapor pressures of these five compounds (25 °C) were estimated by a capillary gas chromatographic method and varied from 8.7 × 10−3 to 8.4 × 10−8 torr. The compounds were irradiated for 15 d on an air-dried sandy loam soil surface. The photolysis rate profiles of the four aryl ketones with vapor pressures from 1.3 × 10−3 torr to 8.4 × 10−8 torr were identical within experimental error, whereas the most volatile congener, hexanophenone, showed approximately 10% greater loss. Volatilization of hexanophenone appears to have caused the compound to move into the light-exposed soil surface to a greater extent than the other compounds. These results suggest that vaporization is not important for loss or transport of the compounds with vapor pressures less than 1.3 × 10−3 torr on air-dried soils within the 15-d irradiation.
Effects of low dissolved oxygen on survival, growth and reproduction of Daphnia, Hyalella and Gammarus
Authors: Nebeker Alan V. , Dominguez Stephen E. , Chapman Gary A. , Onjukka Samuel T. , Stevens Donald G. 
Published: March 2010

Abstract
Daphnia magna, Daphnia pulex, Hyalella azteca, and Gammarus lacustris were exposed to low dissolved oxygen concentrations in the laboratory. Acute and chronic exposures were conducted to develop data for use in the U.S. Environmental Protection Agency's (EPA's) water quality criteria document for dissolved oxygen. Daphnia magna had two 48-h LC50s (50% mortality) of 0.6 and 0.7 mg/L, a highest-adverse-effect concentration of 0.6, and a lowest-no-adverse-effect concentration of 0.9 mg/L O2 (based on reproduction). Daphnia pulex had a 48-h LC50 of 0.5, two 96-h LC50s of 0.4 and 0.7, a highest-adverse-effect concentration of 1.6, and a lowest-no-adverse-effect concentration of 2.1 mg/L O2 (based on reproduction). Hyalella azteca had 96-h and 30-d LC50s of &lt;0.3 mg/L, a highest-adverse-effect concentration of 1.2, and a lowest-no-adverse-effect concentration of &gt; 1.2 (based on reproduction). Gammarus lacustris had two 7-d LC50s of &lt;0.2 mg/L, a highest-adverse-effect concentration of &lt;0.2, and a lowest-no-adverse-effect concentration of 0.1 mg/L O2 (based on survival). Lack of access to the water surface increased mortality. Nitrogen-stripped and vacuum-degassed test water produced the same mortality. Results of this study indicate that dissolved oxygen concentrations adequate to avoid impairment of fish production, as outlined in the EPA's water quality criteria document, should provide reasonable protection for these four species.
Comparative acute sensitivity of larval topsmelt, Atherinops affinis, and inland silverside, Menidia beryllina, to 11 chemicals
Authors: Hemmer Michael J. , Middaugh Douglas P. , Comparetta Valerie 
Published: March 2010

Abstract
Larval topsmelt (Atherinops affinis) and inland silversides (Menidia beryllina) were exposed in 96-h static acute toxicity tests to 11 chemicals to determine the relative sensitivity of the two atherinid species. High to low LC50 ratios for endosulfan, methoxychlor, carbophenothion, chlorpyrifos, terbufos, fenvalerate, permethrin, 4-nitrophenol, and sodium lauryl sulfate were within a factor of &lt;2 for the two species. Atherinops affinis was more sensitive to both azinphos-methyl and 2,4-dinitrophenol by factors of 6.7 and 4.4, respectively. Comparisons of the relative sensitivity of Atherinops affinis with three freshwater fish species (Lepomis macrochirus, Oncorhynchus mykiss, Pimephales promelas) and one estuarine fish species (Cyprinodon variegatus) are presented. Sensitivities were similar between Atherinops affinis and the two most sensitive freshwater species, Lepomis macrochirus and Oncorhynchus mykiss. Atherinops affinis is easily transported, cultured, and maintained in the laboratory and readily adaptable for use in toxicological studies.
Use of the mayfly Stenonema Modestum (Heptageniidae) in subacute toxicity assessments
Authors: Diamond Jerome M. , Winchester Erik L. , Mackler Donald G. , Gruber David 
Published: March 2010

Abstract
This study presents the results of subacute toxicity testing with the mayfly (Ephemeroptera), species Stenonema modestum (Heptageniidae). This species is ubiquitous to many streams in the eastern United States and Canada and is associated with unpolluted sediments and water. The results show that counts of molts or exuviae over a 7–14-d exposure period can be a sensitive indicator of chronic growth effects. Molt production was a more sensitive indicator of pollutant effects than length of organism or width of head capsule measurements. Tests using coal mine effluents indicated that the 7-d molt production end point was often more sensitive than the 14-d molt or survival end point. This was due to either a short-term stimulatory effect on molting or effluent variability over time. Molt stimulation was not observed in tests using NaCl or silver nitrate. Tests with these compounds and coal mine effluents demonstrated that the methods and end points provide repeatable and relatively sensitive data. Test precision was comparable to U.S. Environmental Protection Agency 7-d short-term chronic tests. Molt production of Stenonema modestum in laboratory tests proved to be a reliable predictor of instream effects due to a metal-finishing effluent. Furthermore, simultaneous tests of sediment elutriates and ambient samples from the stream pinpointed probable mechanisms behind the observed instream impact on Stenonema modestum. This method should be amenable to other mayfly species, making it a potentially useful tool in site-specific water quality and sediment quality studies.
Toxicity of trace element and salinity mixtures to striped bass (Morone saxatilis) and Daphnia magna
Authors: Dwyer F. J. , Burch S. A. , Ingersoll C. G. , Hunn J. B. 
Published: March 2010

Abstract
Acute toxicity tests with reconstituted water were conducted to investigate the relationship between water hardness, salinity, and a mixture of trace elements found in irrigation drain waters entering Stillwater Wildlife Management Area (SWMA), near Fallon, Nevada. The SWMA has been the site of many fish kills in recent years, and previous toxicity studies indicated that one drain water, Pintail Bay, was acutely toxic to organisms acclimated or cultured in fresh water or salt water. This toxicity could reflect both the ionic composition of this saline water and the presence of trace elements. The lowest water salinity tested with Daphnia magna was near the upper salinity tolerance of these organisms; therefore, we were unable to differentiate between the toxic effects of ion composition and those of trace elements. In toxicity tests conducted with striped bass (Morone saxatilis), we found that the extent to which salinity was lethal to striped bass depended on the ion composition of that salinity. Survival of striped bass increased as hardness increased. In addition, a trace element mixture was toxic to striped bass, even though the concentrations of individual elements were below expected acutely lethal concentrations. Although salinity is an important water quality characteristic, the ionic composition of the water must be considered when one assesses the hazard of irrigation drain waters to aquatic organisms.
Uptake and accumulation of selenium by terrestrial plants growing on a coal fly ash landfill. Part I: Corn
Authors: Arthur Mary A. , Rubin Gail , Schneider Robert E. , Weinstein Leonard H. 
Published: March 2010

Abstract
This study was conducted to examine the suitability of growing corn (Zea mays L.) on a closed coal fly ash landfill. Previous work indicated that selenium (Se) was the potentially toxic element most likely to be taken up by plants grown on these landfills. This experiment tested differences in Se concentration in three cultivars of corn — Agway 135 (Agway, Inc., Syracuse, NY), Halsey 2273 (Halsey Farms, Ithaca, NY), and Golden Cross Bantam (Agway, Inc., Syracuse, NY) — and two cultivation techniques — no-till and conventional. Selenium concentrations in corn grown on the landfill were consistently higher than those in corn grown on nonlandfill sites. There were no significant differences among two field corn cultivars and one sweet corn cultivar in Se concentrations in vegetative tissues harvested in August 1989. However, there were significant differences between the two field corn cultivars in the Se concentrations of leaves and kernels harvested in October 1989. Corn grown with no-till agriculture had significantly higher concentrations of Se in leaves and kernels never attained toxic levels, indicating that corn grown on fly ash landfills may be safe for human or livestock consumption. However, large variability among varieties and tissues suggests that the use of fly ash landfills for growing agricultural crops should be undertaken only after extensive field trials.
Interaction of naturally occurring neurotoxins and the pyrethroid insecticide deltamethrin with rainbow trout (Oncorhynchus Mykiss) brain sodium channels
Authors: Rubin Jared G. , Soderlund David M. 
Published: March 2010

Abstract
A radiosodium flux assay was employed to characterize the pharmacological properties of trout brain voltage-sensitive sodium channels and to define the response of those channels to the synthetic pyrethroid insecticide deltamethrin The uptake of 22Na+ into trout brain synaptoneurosomes was measured in the presence of a number of sodium channel-directed ligands The sodium channel activators aconitine, veratridine, and batrachotoxin stimulated 22Na+ uptake into trout brain synaptoneurosomes in a dose-dependent manner Batrachotoxin was the most efficacious and potent activator having a maximal sodium uptake at saturating concentrations (Emax) of 6 2 nmol/mg protein and a concentration producing a half maximal response (K0 5) of 3 5 μM Veratridine and aconitine produced Emax values of 3 3 and 3 8 nmol/mg protein and K0 5 values of 16 2 and 11 9 μM, respectively Scorpion (Leiurus quinquestriatus) venom (10 μg per incubation) lowered the K0 5 of batrachotoxin, aconitine, and veratridine and increased Emax for aconitine and veratridine Concentrations of tetrodotoxin above 1 μM completely inhibited 22Na+ uptake The effects of the pyrethroid insecticide deltamethrin on activator-dependent 22Na+ flux were measured to determine if the hypersensitivity of fish to pyrethroid intoxication was related to intrinsic properties of the piscine sodium channel Deltamethrin (20 μM) enhanced veratridine- but not aconitine-dependent 22Na+ flux Deltamethrin also caused a three-fold shift in the potency of batrachotoxin with no effect on Emax Our results demonstrate the presence of functional sodium channels in trout brain synaptoneurosomes that share many of the pharmacological properties of mammalian voltage-sensitive sodium channels However, the sodium uptake assay employed in this study has limitations for assessing pyrethroid potencies in piscine brain preparations
Performance characteristics of effluent toxicity tests: Variability and its implications for regulatory policy
Authors: Warren-Hicks William , Parkhurst Benjamin R. 
Published: March 2010

Abstract
An essential consideration when imposing a requirement for, or evaluating the results generated by, effluent toxicity tests in the National Pollutant Discharge Elimination System (NPDES) permit program is the amount of uncertainty in the measured test end point Variability in effluent toxicity test results is explored by examining round-robin test data with Daphnia magna, fathead minnows, and Certodaphnia dubia as test organisms Inter and intralaboratory percentages of survival of the test organisms are examined by using plots, descriptive statistics, and logistic regression models The results of the analyses demonstrate that the variation in survival is large (0-100% for some test solutions) In addition, the amount of variability is shown to be a function of the toxicity of the test solution The variability in survival is shown to be larger than the variability associated with the LC50 (a model-based end point) The large variability in effluent toxicity tests can have significant implications for the interpretation of toxicity test results used to measure compliance with effluent toxicity limits
Effects of chlorinated phenols on rat embryonic and hepatic mitochondrial oxidative phosphorylation
Authors: Narasimhan Tumkur R. , Safe Stephen H. , Mayura Kittane , Clement Beverly A. , Phillips Timothy D. 
Published: March 2010

Abstract
Chlorinated phenols (CPs), including pentachlorophenol, selected positional isomers from each major group of CPs, and phenol were previously selected from 38 possible compounds and ranked according to developmental toxicity. The present study was designed to utilize these compounds (and a variety of chemical derivatives) to elucidate the mechanism(s) of developmental toxicity of the chlorinated phenols. Mitochondria were isolated by differential centrifugation from rat embryos (REM) and maternal liver (MLM) on day 15 of gestation. The higher CPs, i.e., pentachlorophenol (C5P), 2,3,4,5-tetrachlorophenol (2,3,4,5-C4P), and 2,3,5-trichlorophenol (2,3,5-C3P) at concentrations &gt; 1.33 μM, inhibited ADP phosphorylation and state 4 respiration in the presence of either glutamate plus malate or α-ketoglutarate or succinate. These compounds also exerted a significant uncoupling activity at a concentration of 1.33 μM, with C5P &gt; 2,3,4,5-C4P &gt; 2,3,5-C3P. The lower CPs, i.e., 3,5-dichlorophenol (3,5-C2P), 4-chlorophenol (4-CP), and phenol, produced comparable mitochondrial effects, but only at a higher concentration (20 μM). Enhanced mitochondrial ATPase activity (with and without Mg2+) was induced by C5P, 2,3,4,5-C4P and 2,3,5-C3P at concentrations that exhibited maximum uncoupling activity. The CPs (except for the derivative C5P-anisole) caused significant mitochondrial swelling. The reversal of oligomycin-inhibited respiration by C5P from REM or MLM was also reproducible in the intact Hydra attenuata. A correlation of 0.9 (p = 0.0151) between CP-induced uncoupling activity and the reciprocal of the minimal affective concentration in the Hydra developmental assay was observed. These findings suggest that CPs may elicit their effects by interacting with target cell mitochondria.
Influence of xanthates on the uptake of 109Cd by eurasian dace (Phoxinus phoxinus) and rainbow trout (oncorhynchus mykiss)
Authors: Block Mats , Glynn Anders Wicklund 
Published: March 2010

Abstract
Xanthates form hydrophobic complexes with heavy metals and may therefore have the potential to facilitate the uptake of metals from water by fish. In this paper results are presented supporting the hypothesis that the increased availability is due to the hydrophobic properties of the complexes.
Copper toxicity to Paratya australiensis. IV. Relationship with ecdysis
Authors: Daly Helen R. , Hart Barry T. , Campbell Ian C. 
Published: March 2010

Abstract
Postmolt individuals of the freshwater prawn Paratya australiensis were more sensitive to copper toxicity than individuals at other stages of the molt cycle. In contrast to other reports, molting frequently was not increased by exposure to sublethal concentrations of copper.
The role of property-reactivity relationships in meeting the EPA's needs for environmental fate constants
Authors: Donaldson William T. 
Published: March 2010

Abstract
During the next 10 years, the Environmental Protection Agency may consider as many as 70,000 chemicals for potential risk to humans and the environment. As many as 14 kinetic and equilibrium constants can be required for predicting the fate and transport of each chemical, and relatively few reliable constants are available in the literature. Laboratory measurement of the needed constants is prohibitively expensive (as much as $7 billion for all constants and chemicals combined) and too slow for rapid response to site-specific evaluations. Development of reliable computational methods holds promise of a 100-to 1000-fold reduction in cost of providing fate constants within a reasonable time frame.
Prediction of octanol/water partition coefficient (KOW) with algorithmically derived variables
Authors: Niemi Gerald J. , Basak Subhash C. , Grunwald Greg , Veith Gilman D. 
Published: March 2010

Abstract
A statistical model was developed with algorithmically derived independent variables based on chemical structure for prediction of octanol/water partition coefficients (Kow) measured for more than 4,000 chemicals. The procedure first classified the chemicals into 14 groups based on the number of hydrogen bonds, and then best-subsets, multiple-regression analysis was used to predict Kow within groups. In addition, a training set/test set approach was used to provide an independent evaluation of the sensitivity of the model to the number of chemicals and variables used within each group. In general, the explained variation (r2) was higher and the standard error of the estimates (see) lower in the training sets as compared with the test set groups, whereas analyses of the combined data sets were generally intermediate. Explained variation among the 14 groups, using the combined data sets, ranged from 63 to 90%, and see ranged from 0.37 to 0.78 in logarithmic units. Plots of the residuals indicated a normal scatter. These results are similar to reported error rates in other models.
Quantitative structure-activity relationships of nonspecific and specific toxicants in several organism species
Authors: Ikemoto Yuji , Motoba Kazuhiko , Suzuki Takashi , Uchida Matazaemon 
Published: March 2010

Abstract
The toxicities to Oryzias latipes, Daphnia pulex, and Chlorella vulgaris of nonspecific toxicants (alkanols, substituted benzenes, and alkyl toluates) were well collineated with the logarithm of the octanol/water partition coefficient, log Kow. However, specific toxicants such as 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), lindane, diflubenzuron, rotenone, buprofezin, dieldrin, 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT), and fenvalerate exhibited excess toxicities dependent on the test organism species. The species-specific excess toxicities were much higher than those expected from log Kow and seemed to appear only when the test organisms possessed the specific sites for the toxicants. However, the toxicities of n-butyl- and n-propyl-p-toluates to Oryzias latipes were slightly lower than those predicted from log Kow. The toxicity alleviation corresponded well to the ester biodegradability measured in the fish toxicity assay system. Thus simple quantitative structure-activity relationships (QSARs), using solely log Kow with an appropriate set of compounds and bioassay systems, are useful not only for predicting the environmental toxicity of nonspecific toxicants and specific toxicants, including their mechanism of action, but also for assessment of their biodegradability.
An equation describing the time course and variability in uptake and toxicity of narcotic chemicals to fish
Authors: MacKay D. , Puig H. , McCarty L. S. 
Published: March 2010

Abstract
An equation is proposed to express the time course of uptake of organic chemicals by fish. The chemicals' octanol/water partition coefficients are used to describe equilibrium partitioning, whereas the clearance rate constant, estimated as a function of water- and organic-phase series resistances to transport, is used to describe the time course of uptake. The probability of the concentration of chemical in the fish causing a defined toxic end point is expressed by using a modified Weibull distribution function that contains an adjustable parameter describing variability in organism response. The effect of metabolism can be included if desired. The combined uptake and probability equations are tested by using mortality data for fathead minnows exposed to 18 narcotic chemicals. A single set of parameters is obtained to fit the entire data set. The equation highlights the importance of considering the kinetics of toxicant accumulation when interpreting toxicity results, especially for hydrophobic chemicals, and reinforces the fact that a common organism residue level (in either molar volume or molarity) is associated with 50% mortality in acute bioassays with narcotic organic chemicals. Assorted features of the equations and their applicability to toxicants with specific modes of action are discussed.
Ecosystem-level changes that may be expected in a changing global climate: A british columbia perspective
Authors: Kimmins James P. , Lavender Denis P. 
Published: March 2010

Abstract
British Columbia is a vast province encompassing a wide latitudinal and elevational range. Four of the five major classes of climate in the world are found in British Columbia, where prevailing westerly winds from the Pacific and a series of north-south mountain ranges have produced widely differing local climates. The predicted global warming may result in the migration of species and communities upslope and toward the north, but the heterogeneous nature of the present landscape suggests that such migration may not be as pronounced as that likely to occur in regions of Canada with less relief. Effects of climatic warming on long-lived temperate zone trees include possible increased frost damage in early spring; reduced seed production; increased insect and disease incidence; increased damage to forests by wildfire; and, in the warmer parts of coastal British Columbia, a winter climate too warm to satisfy the chilling requirements of some perennial plants.
Forest health along a wet sulfate/ph deposition gradient in north-central pennsylvania
Authors: Nash Bruce L. , Davis Donald D. , Skelly John M. 
Published: March 2010

Abstract
A well-defined gradient of wet atmospheric depositions characterized by SO4, NO3, H, and NH4 ions has been described in north-central Pennsylvania. The forests of this region are of the oak/hickory type as they extend across the Allegheny Plateau. Sulfate levels along a 160-km west-east gradient varied from approximately 40 kg/ha to 25 kg/ha in the western and eastern portions, respectively. The objective of this research project was to determine if forest trees along the gradient showed anomalous characteristics that might be related to acidic atmospheric deposition. Trees were relatively healthy across the gradient, as measured by observations of crown transparency, twig dieback, and trunk condition. No general relationship was apparent between overall tree health and deposition patterns. Specific disorders noted at greater frequencies at the high deposition portion of the gradient included the presence of insect borers on white oak trunks and early fall coloration of red maple. Disorders observed at greater frequencies at the low deposition portion of the gradient included twig and branch dieback of red oak, white oak, and red maple; chlorosis of red oak; and thrips injury of red maple. A direct cause-and-effect relationship between the pollution gradient and these disorders has not been established.