bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of incubation temperature and warm-water misting on hatching success in artificially incubated mallard duck eggs
Authors: Stubblefield William A. , Toll Paul A. 
Published: March 2010

Abstract
Artificial incubation of eggs is employed in one-generation avian reproduction studies conducted under laboratory conditions. Maximizing overall hatch success while minimizing variability due to experimental methods can increase statistical power for quantifying effects caused by the test material. This study evaluated the effects of incubation temperature and daily warm-water misting of duck eggs on hatching success in a 2 × 2 matrix. Treatment groups were subjected to incubation temperatures of 37.2 or 37.5°C, with (M) or without (NM) misting. Eggs were collected daily from 15 breeding pairs per treatment group during a 10-week laying period. Within appropriate test groups, eggs were misted daily throughout the 24-d incubation and 4-d hatching period. Hatching success (as a percentage of fertile eggs) was 71, 32, 18, and 10 for the 37.5 M, 37.5 NM, 37.2 M, and 37.2 NM groups, respectively. Egg weight significantly decreased, as a percentage of initial egg weight, in misted eggs; no temperature-related differences in egg weight were observed. Results indicate that an incubation temperature of 37.5°C with daily warm-water misting proved to be the most effective treatment for maximizing overall hatching success.
Rapid toxicity screening tests for aquatic biota 1. Methodology and experiments with Daphnia magna
Authors: Janssen C. R. , Persoone G. 
Published: March 2010

Abstract
A promising new and rapid toxicity screening test was developed, the concept and principles of which are presented. The method consists of visual observation of in vivo inhibition of an enzymatic process, using a fluorescent substrate. Juvenile Daphnia magna was exposed to a toxicant dilution series for 1 h, after which the substrate was added and the enzymatic inhibition (absence of fluorescence) was observed visually, using a long-wave UV light (385 mm). The 1-h EC50 results of 11 pure compounds are presented and compared to the conventional 24- and 48-h Daphnia magna EC50s. All 1-h “fluorescence” EC50s were of the same order of magnitude and correlated very well with the 24- and 48-h EC50s. The sensitivity and reproducibility of this cost-effective screening test were compared to those of the Microtoxr̀ test. The scope for application and the potential of this new rapid toxicity screening test are evaluated.
Bioaccumulation and elimination of chlordane by selected intertidal benthic fauna
Authors: Wilcock Robert J. , Pridmore Rick D. , Thrush Simon F. , Cummings Vonda J. , Hewitt Judi E. , Smith Terrence J. 
Published: March 2010

Abstract
Bioaccumulation and elimination of nine principal components of technical chlordane applied to a previously uncontaminated intertidal sand flat were observed in adults of the bivalve species Chione stutchburyi and Tellina liliana, the gastropod Amphibola crenata, and polychaetes (Glycera americana, Nicon aestuarinensis, and Platynereis australis). The patterns of accumulation differed markedly between species, depending on whether the organisms acquired chlordane predominantly from the sediment phase or from both sediment and water phases. The surface-dwelling (Amphibola crenata) or surface-feeding (Tellina liliana) species attained chlordane levels up to three times that of the suspension feeder, Chione stutchburyi, a short time after application. The lipid-normalized bioconcentration curves for both shellfish species declined to similar steady-state values, which suggested that simple equilibrium partitioning between organism lipid and sediment organic carbon phases regulates long-term bioconcentration. The composition of the adsorbed chlordane, although very similar to that of the technical product applied to the sand flat, also showed some species dependence with a preference for the more chlorinated components of chlordane to accumulate in the sediment-feeding species. No traces of the metabolites oxychlordane and heptachlor epoxide were found in any of the species tested over the 100-d duration of the study.
Modeling reproductive toxicity in Ceriodaphnia tests
Authors: Bailer A. John , Oris James T. 
Published: March 2010

Abstract
A model for Ceriodaphnia dubia reproductive toxicity outcomes is presented. This model assumes that the number of young is a Poisson-distributed random variable and that the mean number of young can be modeled using an exponential term involving a polynomial in the test concentrations. Given these assumptions, a modeling procedure for reproductive outcomes is developed and is used to derive an estimate of potency of the chemical under test. Confidence intervals for this estimate are obtained using a bootstrap resampling procedure.
Fate of linear alkylbenzene sulfonate in the environment
Authors: McAvoy D. C. , Eckhoff W.S. , Rapaport R.A. 
Published: March 2010

Abstract
An extensive monitoring study was conducted to determine the fate of linear alkylbenzene sulfonate (LAS) during wastewater treatment and in the environment. Results showed that LAS was highly removed during activated sludge (99.3 ± 0.6%), lagoon (98.5 ± 1.8%), oxidation ditch (98.0 ± 4.2%), and rotating biological contact (96.2 ± 6.1%) treatment, with poorer removals observed at trickling filter (77.4 ± 15.5%) facilities. Concentrations of LAS in anaerobically digested sludge (10,462 ± 5170 μg/g) were one to two orders of magnitude greater than those observed for aerobically digested sludge (152 ± 119 μg/g), illustrating that LAS is rapidly degraded during aerobic sludge treatment. Receiving water concentrations of LAS in rivers of low effluent dilution were generally &lt; 50 μg/L. Elevated river sediment concentrations of LAS were observed only below the outfall of trickling filter treatment plants (59.7-182.1 μg/g). Alkyl chain lengths of LAS averaged 12.0 carbon units in most environmental compartments, with the exception of sludge solids and river sediments, in which an enrichment of longer chain lengths was observed. Measured concentrations of LAS in river waters under critical low flow conditions were in agreement with PG-GRiDS model predictions [5], thus supporting the validity of the modeling approach.
Reduced chromosomal puffing in Chironomus tentans as a biomarker for potentially genotoxic substances
Authors: Bentivegna C.S. , Cooper K.R. 
Published: March 2010

Abstract
Chromosomal puffing in the salivary glands of larval Chironomus tentans was developed as a biomarker for genotoxic substances. Reduced chromosomal puffing was considered an indication of decreased RNA synthesis. Third- or fourth-instar larvae were exposed to test chemicals in an artificial substrate under static conditions. Chromosomes from glands of individual larvae were stained with methyl green and pyronin Y. The widths of Balbiani rings I and II (large puffs on chromosome IV) were measured. Three carcinogens with different mechanisms of action were tested, benzo[a]pyrene (BaP), actinomycin D (Act D), and dimethylnitrosamine (DMN). Puff size was statistically reduced by all three chemicals with varying potency. Lowest-observable-effect levels (LOEL) were 0.5 nmol BaP, 6.0 nmol Act D, and 243,000 nmol DMN. The degree of response was influenced by exposure time, applied dose, individual sensitivity, and possibly chemical hydrophobicity. Biomarker specificity was determined by testing a weak carcinogen, benzo[e]pyrene (BeP), and an acutely toxic noncarcinogen, naphthalene (NP). The effective dose of BeP (LOEL = 250 nmol) was four orders of magnitude higher than that of BaP. Only lethal doses of NP had statistically significant effects on puff size, LD50 = 25,000 (34,300-15,700) nmol. Approximately 40% of the larvae in our laboratory population appeared tolerant to the effects of BaP. Advantages of this biomarker were its association with a known mechanism of action and measurement of the whole-organism integrated response.
Acid-volatile sulfide (AVS) in a seasonally anoxic mesotrophic lake: Seasonal and spatial changes in sediment AVS
Authors: Howard Dorothy E. , Evans R. Douglas 
Published: March 2010

Abstract
Acid-volatile sulfide (AVS) is an operational definition for the sulfides removed from sediment by cold acid extraction. It has been proposed that this fraction could be used as an indicator of divalent metal toxicity (e.g., Cd, Ni, Hg), as it increases the metal-binding capacity of sediments and hence renders metals unavailable to biota. Before AVS can be used as a predictive tool in freshwater systems, we must develop a better understanding of the impact of seasonal turnover events on its geochemistry. An in-depth study of spatial and temporal variation in AVS concentrations in a seasonally anoxic mesotrophic lake is presented. Comparisons are made to AVS in other lakes, with reference to its utilization as a sediment toxicity parameter. Results indicate that AVS increases during anoxic periods and that lake morphology is important due to sediment focusing. Seasonal variations in AVS concentration were observed that may change the potential toxicity of metals in freshwater sediments.
Degradation of organochlorine pesticides, particularly endosulfan, by Trichoderma harzianum
Authors: Katayama Arata , Matsumura Fumio 
Published: March 2010

Abstract
A fungus, Trichoderma harzianum, was found to degrade DDT, dieldrin, endosulfan, pentachloronitrobenzene, and pentachlorophenol but not hexachlorocyclohexane. The fungus degraded endosulfan under various nutritional conditions throughout its growth stages. Endosulfan sulfate and endosulfan diol were detected as the major fungal metabolites of endosulfan. Piperonyl butoxide, when added to the growth medium, completely inhibited the endosulfan degradation. Di-n-propyl malaoxon also inhibited the overall endosulfan degradation, but under such an inhibitory condition the formation of endosulfan sulfate was still observed. Using a cell-free preparation from Trichoderma harzianum, we could demonstrate that endosulfan metabolism in vitro was stimulated by exogenously added NADPH. Together with the evidence that the initial metabolic product of endosulfan was endosulfan sulfate, we concluded that the major enzyme system responsible in Trichoderma harzianum responsible for degradation of endosulfan is an oxidative system.
Chemical and toxicological testing of composted explosives-contaminated soil
Authors: Griest W.H. , Stewart A.J. , Tyndall R.L. , Caton J.E. , Ho C.-H. , Ironside K.S. , Caldwell W.M. , Tan E. 
Published: March 2010

Abstract
Static-pile and mechanically stirred composts of explosives-contaminated soil at the Umatilla Army Depot Activity (UMDA, Umatilla, OR) in a field composting optimization study were characterized chemically and toxicologically. The concentrations of extractable explosives (e.g., 2,4,6-trinitrotoluene) in the composts and their aqueous leachates, the mutagenicity of organic solvent extracts from the composts, and the toxicity of compost aqueous leachates to Ceriodaphnia dubia all decreased considerably with 20 d of composting. After 44 d (mechanical composters) or 90 d (static piles) of composting, the toxicity, mutagenicity, and concentrations of extractable explosives decreased more than 90% in some cases. The composting efficiency was generally inversely proportional to the percentage (v/v) of contaminated soil. Composting in static piles was efficient up to about 20% (v/v) of contaminated soil; composting in the mechanically stirred composters was efficient up to about 25% soil. Mechanical composting was more efficient than composting in static piles. The main conclusion of this study is that composting can effectively remediate explosives-contaminated soil and sediment. However, low levels of explosives and metabolites, bacterial mutagenicity, and leachable toxicity to Ceriodaphnia may remain after composting. The sources of residual toxicity and mutagenicity and the ultimate fate of the explosives are unknown.
Kinetics, products, mechanisms and QSARs for the hydrolytic transformation of aromatic nitriles in anaerobic sediment slurries
Authors: Peijnenburg Willie J.G.M. , de Beer Karin G.M. , den Hollander Henri A. , Stegeman Miranda H.L. , Verboom Hans 
Published: March 2010

Abstract
The degradation of several substituted benzonitriles was examined in anaerobic sediment-water systems under laboratory conditions. Formation of the corresponding benzoic acids was the main transformation process taking place. The pseudo-first-order rate constants of this process were shown to depend on both the chemical structure of the starting compound and the sediment characteristics. The starting compounds were selected with the aim of obtaining a maximum variation in chemical reactivity and physical properties, and the sediments were selected with the aim of assessing several environmental factors influencing the kinetics of transformation. Quantitative structure-activity relationships were developed for both ortho- and meta/para-substituted nitriles by relating pseudo-first-order disappearance rate constants for reductive hydrolysis of 27 aromatic nitriles in anoxic sediment slurries to some readily available molecular descriptors. The best correlations were obtained with the octanol/water partition coefficient of the nitriles and the summation of the inductive constants of the substituents as parameters. The correlations were strongly enhanced by taking into account the fraction of the compounds sorbed to the solid phase. Also it was found that upon correction for sorption, rate constants for reductive hydrolysis of three substituted benzonitriles obtained in six sediment samples did not differ significantly. Thus the obtained relationships may be used to calculate rates of transformation of given aromatic nitriles in given sediment systems
External validation of a QSAR for the acute toxicity of halogenated aliphatic hydrocarbons
Authors: Eriksson Lennart , Jonsson Jörgen , Berglind Rune 
Published: March 2010

Abstract
The validation of the predictive capability of a quantitative structure-activity relationship (QSAR) is a significant step toward the construction of a reliable model. This point is discussed and illustrated with data for a class of halogenated aliphatic hydrocarbons. For this class of compounds, a QSAR concerning their acute toxicity toward rat was recently published. This QSAR is verified in this study by selecting and testing an external validation set comprising six compounds. The QSAR is also used for predicting the acute toxicity of 38 nontested members of this class.
An alternative avian population estimate for overdispersed populations for use in mark-recapture studies of pesticide effects
Authors: Madrigal J.L. , Carter M.W. , Parrish J.R. , Booth G.M. , Fischer D.L. 
Published: March 2010

Abstract
Statistical models that have been commonly applied to mark-recapture/resighting data, such as the Jolly-Seber estimate, assume that capture and recapture/resighting probabilities are constant for all birds. This assumption is likely false. An alternative approach that is based on the beta-binomial distribution that allows for heterogeneous capture/recapture is presented. Use of the approach is illustrated with data obtained in a field study of NEMACUR® 15G applications. A total of 24,000 simulations indicated that the power of the beta-binomial in detecting a 10% reduction in survival varies from 56.2 to 99% in resighting data and is more than 84% in recapture data. Population estimates were obtained using the maximum likelihood method. Under conditions of heterogeneous probabilities, more precise estimates of population size were produced with this approach than with the Jolly-Seber method.
Comparative diazinon toxicity in guppy and zebra fish: Different role of oxidative metabolism
Authors: Keizer Johannes , D'Agostino Giuseppina , Gramenzi Franco , Vittozzi Luciano , Nagel Roland 
Published: March 2010

Abstract
Guppies pretreated with 1.1 μmol/L diazinon (0.5 times the LC50 with the guppy) for 7 d were less susceptible to the toxicity of the compound. The LC50 in these fish was about five times higher than that in nonpretreated animals. The lethal body burden and the slope of the concentration-response curve of diazinon in pretreated guppies were similar to those in zebra fish. The 7-d pretreatment of zebra fish with 12 μmol/L diazinon (0.5 times the LC50 with the zebra fish) did not affect the susceptibility of this species to diazinon. The pretreatment of guppies resulted in a strong inhibition of the formation of diazoxon and pyrimidinol during incubations of diazinon with the hepatic postmitochondrial supernatant. During exposure of guppies and zebra fish to diazinon, the tissue concentration of the metabolite, pyrimidinol, initially increased and then declined to very low levels. In the guppy, concurrently with the decrease of the metabolite concentration, the parent compound began accumulating again after a temporary steady state. The hypotheses of this paper are that the toxicity of diazinon in the guppy is due to its metabolism to a highly toxic metabolite, likely diazoxon; and in zebra fish or pretreated guppies having low rates of diazinon metabolism toxicity is due to the accumulation of the parent compound.
pH-Dependent toxicity of Cd, Cu, Ni, Pb and Zn toCeriodaphnia dubia, Pimephales promelas, Hyalella aztecaandLumbriculus variegatus
Authors: Schubauer-Berigan Mary K. , Dierkes Joseph R. , Monson Philip D. , Ankley Gerald T. 
Published: March 2010

AbstractThe speciation and bioavailability of metals are known to be affected by pH. Although many studies have focused on effects on metals of pH changes resulting from lake acidification (i.e., pH change 7 to 4), metal toxicity changes at higher pH values (i.e., pH 6-9) are of great interest to those performing effluent and sediment toxicity testing and toxicity identification evaluations (TIEs). In addition, most previous studies have addressed metal toxicity changes with pH to water-column organisms rather than to benthic or epibenthic species. We tested the acute toxicity of five metals (Cd, Cu, Ni, Pb, and Zn) to Ceriodaphnia dubia, Pimephales promelas, Hyalella azteca, and Lumbriculus variegatus at three pH values (6.3,7.3, and 8.3) in very hard reconstituted water (hardness 300-320 mg/L as CaCO3). Toxicity of Cd, Ni, and Zn was greatest at pH 8.3 and least at pH 6.3 to most of these species. Conversely, the toxicity of Cu and Pb was greatest at pH 6.3 and least at pH 8.3 to most of the species. The acute toxicity of most of the metals to Lumbriculus variegatus was very low and occasionally was above the aqueous solubility of the metal salts in the reconstituted water.
The effects of sodium selenite and selenomethionine on murine limb development in culture
Authors: Rousseaux C.G. , Politis M.J. , Keiner J. 
Published: March 2010

Abstract
Excessive selenium in the environment causes perturbed embryonic development in birds; however, excessive selenium in mammals has not been shown to cause similar maldevelopment. The present study was performed to determine whether the lack of selenium-induced limb defects in mammals is due to either differences in pharmacokinetics or tissue sensitivity to the compound, or both. Sodium selenite (SS) and selenomethionine (SM) were added to BGJb medium containing 20% fetal bovine serum, in which limbs from CD-1 mouse embryos taken 12 d following conception were cultured. Concentrations of SS and SM ranged from 2 to 20 times the level of selenium normally present in fetal bovine serum (0.2, 0.6, 1.0, 2.0, or 4.0 μig/ml). Limbs were grown for 72 h, fixed, stained with Alcian blue GX to highlight cartilage anlagen, and analyzed to determine tissue and anlage areas and shape factors. Sodium selenite induced a concentration-response maldevelopment of ulnar, radius, and humerus anlagen and delayed development of phalanges, whereas SM did not. Changes in development became obvious at SS levels four times normal (0.6 μg/ml). The size and length of anlagen also decreased (p &lt; 0.0001). At six times the concentration of SS (1.0 μg/ml), areas occupied by cartilage anlagen were decreased 20-fold, with virtually no chondrogenesis evident in phalanges at higher concentrations. The results of these studies indicate that SS can cause deficits in early mammalian limb development if the element is allowed to reach the developing tissue, whereas the SM does not. We conclude that tissue differences in response and placental transfer may account for the differences seen among species.
Metal concentrations in feathers of birds from Papua New Guinea forests: Evidence of pollution
Authors: Burger Joanna , Laska Mark , Gochfeld Michael 
Published: March 2010

Abstract
We used the feathers of seven species of birds from New Guinea highland forests to examine concentrations of heavy metals and selenium. We tested the null hypotheses that there were no species, food type, or elevation differences in the concentrations of mercury, lead, cadmium, selenium, chromium, and manganese in the feathers of adults. All species had nondetectable levels of mercury (&lt; 10 ppb). There were significant species differences in cadmium, lead, chromium, selenium, and manganese. Common smokey honeyeaters (Melipotes fumigatus, a fruit and flower feeder) had the lowest levels of all metals; blue-grey robin (Peneothello cyanus, mainly insectivorous) had the highest cadmium and manganese; and several species of birds of paradise (mainly frugivorous) had the highest lead levels. Lead levels were relatively high compared to those reported from feathers of other birds, attributable to the use of leaded gasoline.
Chemical transformation of toxic metals by a Pseudomonas strain from a toxic waste site
Authors: Blake Robert C. , Choate Donna M. , Bardhan Smriti , Revis Nathaniel , Barton Larry L. , Zocco Thomas G. 
Published: March 2010

Abstract
Pseudomonas maltophilia strain O-2, isolated from soil at a toxic waste site in Oak Ridge, Tennessee, catalyzed the transformation and precipitation of numerous toxic metal cations and oxyanions. When a viable inoculum (1%) of O-2 was introduced into nutrient broth containing Hg(II), Cr(VI), Se(IV), Pb(II), Au(III), Cd(II), Te(IV), or Ag(I), effective removal of the toxic metal was complete within 1, 1, 2, 2, 2, 4, 5, and 7 d, respectively. The NADPH-dependent reduction of Hg(II) to Hg0 was catalyzed by an inducible mercuric reductase. The reduction of selenite and tellurite to their insoluble elemental forms appeared to be mediated by an intracellular glutathione reductase that utilized the spontaneously formed bis(glutathio)Se(II) or bis(glutathio)Te(II), respectively, as pseudosubstrates. The three-electron reduction of hexavalent chromium was catalyzed by a membrane-bound chromate reductase. The enzymatic basis for the remaining metal transformations was not immediately apparent. It is anticipated that Pseudomonas maltophilia and related organisms could eventually be exploited for the removal of toxic metal wastes from selected, heavily polluted sites.