bluuebunny/crossref_metadata_2025_split huggingface dataset:
Compartmentalization of permethrin on cotton leaves in the field during a spray application season
Authors: Southwick Lloyd M. , Smith Sammie , Willis Guye H. 
Published: March 2010

Abstract
The insecticide permethrin was applied (10 applications in 6 weeks) to cotton in field plots separated for morning and afternoon applications in early (August to September) and late (September to October) season spray programs. The compartmentalization of permethrin on the leaves was determined throughout the application programs. In each of the four studies, initial surface permethrin residues were 80–90% of the total leaf load. At the end of each study, surface residues had doubled and total leaf content had quadrupled; the surface residues then were 40–45% of the total load. Thus, throughout each phase of the study, a major portion of the leaf permethrin content was at or near the surface where weathering processes occur. The surface residues from the late-season afternoon applications were generally higher than the residues from the early-season afternoon applications. This difference was in line with differences in rainfall, temperature and evaporation rates, which favored higher leaf surface residues in the late season. This residue trend did not appear in the morning samples from the two seasons. The cis:trans isomer ratios of the permethrin residues from the late-season study showed consistently significant decreases, which may have been due in large part to cis-to-trans isomerization.
Effects of aluminum on respiratory responses and spontaneous activity of rainbow trout, Salmo Gairdneri
Authors: Ogilvie D.M. , Stechey D.M. 
Published: March 2010

Abstract
Respiratory responses of juvenile rainbow trout, Salmo gairdneri Richardson, were determined after approximately 26 h of exposure to dechlorinated tap water (at pH 6.0) containing 50, 100, 200 or 500 μg/L of added aluminum. Aluminum exposure produced significant increases in both opercular rate and cough frequency. Changes in the cough rates were proportional to the aluminum level, and the threshold concentration was approximately 100 μg/L. In addition, spontaneous locomotor activity was reduced by aluminum exposure.
Effect of Hexagenia on Daphnia response in sediment toxicity tests
Authors: Malueg K. W. , Schuytema G. S. , Gakstatter J. H. , Krawczyk D. F. 
Published: March 2010

Abstract
The toxicity of 12 freshwater sediments to the water flea, Daphnia magna Straus, and the mayfly nymph, Hexagenia, were tested in recycling laboratory microcosms. The organisms were tested both together and singly. Significant differences in Daphnia mortality between test and control sediments occurred in only two cases in which Daphnia was tested alone, and in five cases in which it was tested with Hexagenia. Significant Hexagenia mortality occurred in only two cases. The results imply that (a) Hexagenia is a less sensitive indicator of freshwater sediment toxicity than is Daphnia and (b) the presence of Hexagenia usually intensifies the Daphnia response. Tests that combine these two organisms are recommended, since Daphnia, although an open-water species, responds not only to dissolved materials in the water but also to particulates released from the sediments by the physical activity of Hexagenia. These types of tests could be used, on a standardized, routine basis, as indicators of potential problems.
Predator—prey (Vole—Cricket) interactions: The effects of wood preservatives
Authors: Gillett James W. , Gile Jay D. , Russell Loren K. 
Published: March 2010

Abstract
The rate of loss of crickets (Acheta domestica L.), with and without the presence of an adventitious predator, the gray-tailed vole (Microtus canicaudus), has been studied in Terrestrial Microcosm Chambers (TMC-II) treated with pine stakes impregnated with creosote, bis(tri-n-butyltin)oxide (TBTO), dieldrin (HEOD), pentachlorophenol (PCP) or a toluene solvent control. The first-order rate of cricket loss (-k) increased only for HEOD, to a maximum at 33 d post-treatment, with oscillations of about a 16-d period. This result infers a “cricket-available” compartment of HEOD and/or metabolites with concentrations that must be greater than those measured in air, soil, water or plants and other biota. When a gravid vole was subsequently added to each TMC, the predation index (Δkv) increased for control and PCP, but declined markedly for creosote and HEOD, and to a lesser extent for TBTO.
Aquatic safety assessment for cationic surfactants
Authors: Lewis Michael A. , Wee Victorio T. 
Published: March 2010

Abstract
The first comprehensive evaluation of the environmental safety of three similar cationic surfactants to aquatic life is reported. Toxicity tests were conducted that exposed freshwater and marine species, representing three trophic levels, to the dialkyl dimethyl ammonium compounds. The studies were conducted in a high-quality laboratory water and in river waters that were used to model realistic receiving streams. Most current laboratory test methods for the assessment of chemical effects on aquatic life do not consider the physical and chemical properties of the test material in surface waters. This safety assessment shows that these considerations are important in developing realistic conclusions about the ecological safety of cationic surfactants. In tests using river water, acute and chronic toxicities and bioconcentration were considerably less than those in corresponding tests conducted in filtered laboratory waters. This reduction in toxicity and/or uptake was attributable to the aqueous insolubility of the surfactants, strong adsorption to natural solids and tendency to form chemical complexes with anionic substances. The mean ratio of the concentration of anionic to cationic surfactants in municipal sewage treatment plant effluent is 4:1. Safety margins were calculated for daphnids and fathead minnows using the ratio of the no observed effect concentration, determined from chronic toxicity tests, to mean measured surface water concentrations. Safety margins for fish and daphnids were 7 and 11, respectively, for a river having a low wastewater effluent dilution factor of 10. For a river with a higher dilution factor of 150, the values were 115 (fish) and 190 (daphnids). Projected safety margins for marine invertebrates and fish were several orders of magnitude greater than those for freshwater species. Based on available information and expected usage levels, the projected environmental impact of these surfactants on aquatic life is minimal.
Hydrolysis studies of aldicarb, Aldicarb sulfoxide and aldicarb sulfone
Authors: Hansen James L. , Spiegel Milton H. 
Published: March 2010

Abstract
Hydrolysis studies were conducted on aldicarb, aldicarb sulfoxide and aldicarb sulfone for 186 to 228 d. These long-term studies show that, for a given temperature, the reaction rate constants for the three compounds are relatively constant below pH 7 and increase rapidly as the pH increases beyond 7. These rate constants generally result in shorter half-lives (under two years in most environments) than previously assumed, and would result in aldicarb residues being less persistent in groundwater than previously expected.
Applicability of microbial toxicity assays to assessment problems
Authors: Gillett James W. , Knittel Martin D. , Jolma Eva , Coulombe Roger 
Published: March 2010

Abstract
Microbial assays of dissolved oxygen (DO) uptake and resazurin reduction (RR) assays were compared with regard to applicability for hazard assessment schemes and determination of bioactive residues in soil and biota. The DO method is simpler and less expensive, but is less sensitive and more variable than the RR method. Both gave highly comparable results with pure or mixed cultures of microbes.
Trace organic contamination of ground water from a rapid infiltration site: A laboratory-Field coordinated study
Authors: Hutchins S. R. , Tomson M. B. , Ward C. H. 
Published: March 2010

Abstract
A previous study at Rice University demonstrated that trace organic compounds in primary and secondary effluents treated in rapid infiltration systems are detected in associated ground water. A direct cause and effect relationship was not established, however, since background data on trace organics in the ground water were not available. Field studies on a rapid infiltration site currently under construction at Fort Polk, Louisiana, have indicated that characteristic trace organics are mostly absent from ground water underlying the site. Therefore, a laboratory study was undertaken to investigate the potential for ground water contamination by trace organics during operation of this system. Four columns were packed with topsoil obtained from one of the basins at the site. Unchlorinated secondary effluent was also obtained from the site and used as feed solution for the columns. Soil columns were operated for a period of 4 months on a 2d flooding/12-d drying cycle to parallel design operation of the rapid infiltration system. Feed solution and column effluents were monitored for 22 trace organics by reverse ion search using capillary gas chromatography/mass spectrometry. Each of nine target trace organics found consistently in the feed solution, with the exception of p-dichlorobenzene, was detected in the column effluents during the first inundation cycle; all target trace organics were detected in the column effluents during subsequent cycles. The concentrations of tetrachloroethylene, p-dichlorobenzene, acetophenone, 2-(methylthio)benzothiazole and bis(2-ethylhexyl)phthalate in the feed solution were generally reduced by passage through the soil column, whereas diethyl phthalate, benzophenone, N-butylbenzenesulfonamide and dibutyl phthalate concentrations were unaffected or enhanced. Addition of mercuric chloride during the seventh and eighth inundation cycles had variable effects for the different compounds. These preliminary results indicate that ground water contamination at the Fort Polk rapid infiltration site can occur once the system begins operation, although concentrations of specific trace organics may be significantly reduced.
Effect of fluctuating lead exposures on lead accumulation by rainbow trout (Salmo gairdneri)
Authors: Hodson Peter V. , Blunt Beverley R. , Borgmann Uwe , Minns Charles K. , McGaw Shelly 
Published: March 2010

Abstract
Contaminant concentrations in aquatic ecosystems vary spatially and temporally, so that surveillance data exhibit a log-normal distribution; i.e., the majority of measurements are low but a few are quite high. These data are best characterized by geometric means. Contaminants that are taken up quickly but excreted slowly should accumlate in fish at concentrations that reflect the highest exposure rather than the geometric mean exposure. To confirm this prediction, blood lead concentrations of rainbow trout were measured after 20-d exposures to concentrations of waterborne lead that fluctuated about a fixed geometric mean. Four levels of exposure variability were used. A lead exposure characterized by wide fluctuations was expected to cause greater lead uptake by trout than the equivalent exposure with less variability. Lead accumulation was best described by the following equation: log10 blood lead concentration (μg/L) = 0.814 + 0.999 log10 waterborne lead (μg/L) + 1.335 × standard deviation of log10 waterborne lead. Increasing lead concentrations and increasing variability of waterborne concentrations increased lead accumulation by trout. These results were accurately predicted by a simple one-compartment model of contaminant kinetics in fish. Applying this model to other contaminants and to hypothetical exposure regimes demonstrated that high depuration rate constants increase the importance of exposures over the previous 24 h. This anaylsis also demonstrated that arithmetic mean exposures were a better way of describing contaminant accumulation by fish than were geometric mean exposures. Therefore, brief (24 h) violations of water quality criteria may cause a greater toxicity to fish than would be expected from simple estimates of the geometric mean concentrations in water. Water quality surveillance programs must be designed to accurately describe both contaminant variance and the arithmetic mean concentration.
Growth optimized algal bioassays for toxicity evaluation
Authors: Klaine S. J. , Ward C. H. 
Published: March 2010

Abstract
Dynamic (flow-through) algal bioassays generally have been found to be more sensitive to toxicants than have static (batch) bioassays, and have led to lower estimates of maximum allowable toxicant concentrations. When growth of Selenastrum capricornutum is optimized, both systems are equally sensitive and quantitatively related to toxicant concentration.
Oxidative degradation of 2,3,7,8-tetrachlorodibenzo-p-dioxin by microorganisms
Authors: Quensen J. F. , Matsumura F. 
Published: March 2010

Abstract
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) was metabolized by pure cultures of Nocardiopsis spp. and Bacillus megaterium. The degree of metabolism was strongly dependent on the solvent used, with ethyl acetate giving the best results. TCDD metabolism by B. megaterium increased when the concentration of soybean extract was reduced from 1.6% to 0.8%. Two TCDD-degrading bacteria were isolated from farm soil that consistently showed a low level of TCDD-degrading activity.
Bioavailability of six organic chemicals to Chironomus Tentans larvae in sediment and water
Authors: Mum D. C. G. , Townsend B. E. , Lockhart W. L. 
Published: March 2010

Abstract
Uptake and elimination of 14C-labeled terbutryn, fluridone, triphenyl phosphate (TPP), trans-permethrin, methoxychlor and 2,4,5,2′,4′,5′-hexachlorobiphenyl (HCBP) by Chironomus tentans larvae were studied in sediment-water systems. Animals were exposed to three different sediments containing 50 to 500 μg/kg (wet weight) of each chemical, or were held in screened containers in water above the treated sediment for 24 or 96-h. Elimination of radioactivity was determined over a 48-h interval. Results were analyzed by use of a one-compartment kinetic model. Larvae exposed in sand or in water above sand had significantly higher concentrations of each chemical than those exposed in or above river (silty) or pond (silty clay) sediments. Uptake of terbutryn and fluridone, two hydrophilic compounds, was similar (24-h exposure) to that of methoxychlor and greater than that for TPP, trans-permethrin or HCBP, due to much greater partitioning of the former compounds into water above each sediment. TPP, trans-permethrin, methoxychlor and HCBP concentrations were significantly higher in larvae from sediment than in animals held in water above sediment. Uptake rate constants from water for each chemical were much greater than those for sediment, but due to the relatively large sediment-to-water ratio (1:5) and the high proportion of chemical in sediment, relative contributions of sediment and water uptake to body burden were similar. Assimilation of each compound by larvae from ingested sediments appeared to be negligible except for TPP and HCBP. Estimates of assimilation of TPP and HCBP in sand-water systems were much greater than those for sediments with higher organic matter content.
Induction of isoflavonoid production in Phaseolus Vulgaris L. leaves by ozone, sulfur dioxide and herbicide stress
Authors: Rubin Baruch , Penner Donald , Saettler A. W. 
Published: March 2010

Abstract
The potential induction of phytoalexin production by stress following exposure to ozone, sulfur dioxide and several herbicides was evaluated in bean (Phaseolus vulgaris L.) cultivars and lines varying in sensitivity to ozone injury. The isoflavonoids, coumestrol and several other coumestans were extracted from leaf tissue after various periods of exposure to ozone, sulfur dioxide or application of various herbicides. Elicitation of isoflavonoid production varied with lines and cultivars, but generally increased with increased plant injury caused by ozone, sulfur dioxide or herbicide.
A method for the qualitative and quantitative characterization of waterborne organosilicon substances
Authors: Mahone L. G. , Garner P. J. , Buch R. R. , Lane T. H. , Tatera J. F. , Smith R. C. , Frye C. L. 
Published: March 2010

Abstract
A novel method has been developed for the qualitative and quantitative characterization of (a) waterborne organosilicon substances, which are present as low-molecular-weight silanols (such as silicone hydrolysis products), and (b) higher-molecular-weight materials (e.g., silicones), which can be caused to undergo hydrolysis to yield such low-molecular-weight silanol-functional materials. This method is capable of good to excellent accuracy and precision in the parts per million range and, with suitable precautions, has the potential for extension to determinations in the low parts per billion range. Although particularly valuable for the analysis of water-soluble species, this method can also be adapted to yield useful information concerning water-insoluble organosilicon materials present in aqueous systems, such as colloidal suspensions, surface films, or sedimentary slurries. Because of its inherent sensitivity and selectivity, this method constitutes a valuable tool for measuring and characterizing the silicone content of industrial and municipal waste waters, surface and ground waters, foods and biological tissues, etc. The determination of water-soluble organosilanol species is accomplished by the acid-catalyzed trimethylsilylation of the silanol functionality with hexamethyldisiloxane (HMDS) followed by gas-liquid chromatographic assay of the resulting HMDS extract. Water-insoluble components are determined by subjecting the sample to acidic predigestion before the addition of the HMDS-derivatizing and extracting reagent. The possibility of dimethyl- or monomethyl-silicon artifacts arising from inadvertent trace cleavage of methyl groups from the HMDS can be determined and/or precluded by the use of hexaethyldisiloxane or perdeutero-HMDS when appropriate.
pH Control of weak electrolyte toxicity to fish
Authors: Hayton William L. , Stehly Guy R. 
Published: March 2010

AbstractA pharmacokinetic model was used to predict the acute toxicity of weak electrolytes to fish as a function of pH. For weak acids, the model predicted that the toxic concentration-pH profile was shifted to the right of the ionized fraction-pH profile. The relative rates of uptake of ionized and nonionized species can be calculated using toxic concentration-pH data.
Response of a salt marsh microbial community to inputs of heavy metals: Aerobic heterotrophic metabolism
Authors: Giblin Anne E. , Piotrowski Michael , Leighty Bruce , Valiela Ivan , Teal John M. 
Published: March 2010

Abstract
The addition of a sterilized, sludge-based fertilizer to experimental salt marsh plots increased both the nitrogen and the heavy metal content of the surface sediment. Aerobic heterotrophic microorganisms collected from these plots differed from microbes collected from control plots in their oxygen uptake rates on a uniform sediment medium both in the presence and absence of metals. When metals were not present, microbes from fertilized plots took up significantly less oxygen that did microbes from control plots. In the presence of metals, oxygen uptake by microbes from both plots was depressed; however, activity of microbes from the fertilized plots was significantly less inhibited than was that of microbes from the control plots, indicating a greater degree of metal tolerance in the former.
To assess the effect of a metal on the microbial community in the absence of nutrient enrichment, chromium solutions were applied to several 1-m2 marsh plots. Microbes from these plots developed a tolerance to both copper and chromium within 1 month. The oxygen uptake on sediment media in the absence of metals did not differ from that demonstrated by nonmetal-tolerant microbes.
Influence of water hardness on fluoride toxicity to rainbow trout
Authors: Pimentel Richard , Bulkley Ross V. 
Published: March 2010

Abstract
Static bioassays were conducted to determine effects of water hardness on toxicity of sodium fluoride to rainbow trout (Salmo gairdneri). Ninety-six hour LC50 values increased from 51 to 193 mg/L [F] as water hardness levels rose from 17 to 385 mg/L CaCO3. Tests of chronic toxicity at different water hardness levels are needed before fluoride standards for aquatic life, such as fish, can be set.
Year and age effects on residues of dieldrin and heptachlor in dead gray bats, franklin county, missouri—1976, 1977, and 1978
Authors: Clark Donald R. , Bunck Christine M. , Cromartie Eugene , Laval Richard K. 
Published: March 2010

Abstract
Dead gray bats (Myotis grisescens) containing lethal concentrations of dieldrin were found beneath a maternity roost in Bat Cave Nos. 2 and 3, Franklin County, Missouri, in 1976, 1977 and 1978. Whereas residues of dieldrin, DDE [1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene] and PCB polychlorinated biphenyls in bats appeared not to change significantly over the 3 years, residues of heptachlor-related chemicals increased in 1977 to potentially dangerous concentrations and remained elevated in 1978. Lethal brain levels of dieldrin in adult bats (geometric mean = 12.1 μg/g), compared with juvenile bats (geometric mean = 6.5 μg/g), indicated that juveniles are nearly twice as sensitive. The estimated population of gray bats (as maximum number of nonflying young) at Bat Cave Nos. 2 and 3 in 1976 and 1978 was 1,800 bats, but in 1979 no bats were present. Dieldrin, perhaps in conjunction with heptachlor, may have caused the decline and disappearance of this colony. However, dieldrin was banned in 1974 and Missouri's authorization to use heptachlor on corn expired in 1981. Furthermore, three organophosphate insecticides (chlorpyrifos, dyfonate and mocap) are to be substituted. We hope that the gray bats remaining in this area of Missouri survive the residues of dieldrin and heptachlor still in their food chains and prove to be unaffected by the new organophosphates.
Altered avoidance behavior of young black ducks fed cadmium
Authors: Heinz Gary H. , Haseltine Susan D. , Sileo Louis 
Published: March 2010

Abstract
Pairs of adult black ducks (Anas rubripes) were fed a diet containing 0, 4 or 40 ppm cadmium as cadmium chloride. One-week-old ducklings that had been fed the same dietary concentrations of cadmium as had their parents were tested for avoidance of a fright stimulus. Ducklings fed 4 ppm cadmium ran significantly farther from the stimulus than did controls or ducklings fed 40 ppm cadmium. Such an alteration in behavior could have harmful effects on wild birds.