bluuebunny/crossref_metadata_2025_split huggingface dataset:
Predicting the occurrence of genetic adaptation to dioxinlike compounds in populations of the estuarine fishFundulus heteroclitus
Authors: Nacci Diane E. , Champlin Denise , Coiro Laura , McKinney Rick , Jayaraman Saro 
Published: March 2010

AbstractA population of the nonmigratory estuarine fish species Fundulus heteroclitus (mummichog) indigenous to a polychlorinated biphenyl (PCB)-contaminated Superfund site (New Bedford Harbor, MA, USA) demonstrated an inherited tolerance to local, dioxinlike contaminants (DLCs). These findings suggest that DLCs have acted as selective agents, allowing the survival of only the most tolerant individuals, forming DLC-adapted populations. We hypothesized that DLC-tolerant mummichog populations would reside where local conditions are toxic to sensitive individuals, and that toxic environmental conditions could be predicted based on responses of sensitive early life stages to laboratory exposures of DLCs. As a measure of DLC tolerance, progeny of field-collected fish were tested in the laboratory with a dioxinlike PCB congener, 3,3′,4,4′,5-pentachlorobiphenyl (PCB 126). Mummichog populations were collected from sites with sediment PCB concentrations predicted to range from nontoxic to toxic. Consistent with predictions, tolerant populations were indigenous to sites with elevated sediment PCB concentrations. Also, as predicted, DLC-tolerant populations were resident to sites far less contaminated than the Superfund site. These results suggest that exposures to persistent, bioaccumulative, and toxic contaminants may produce evolutionary effects on a geographic scale larger than previously envisioned. This study presents an approach and describes a model system that may improve understanding of the scale of occurrence for these potentially irreversible ecological effects.
Comparison of pesticide root zone model 3.12: Runoff predictions with field data
Authors: Singh Piyush , Jones Russell L. 
Published: March 2010

Abstract
As part of a process to improve confidence in the results of regulatory modeling, predictions of pesticide root zone model (PRZM) 3.12 were compared with measured data collected in nine different runoff field studies. This comparison shows that PRZM 3.12 provides a reasonable estimate of chemical runoff at the edge of a field. Simulations based on the best choices for input parameters (no conservatism built into input parameters) are generally within an order of magnitude of measured data, with better agreement observed both for larger events and for cumulative values over the study period. When the model input parameters are calibrated to improve the hydrology, the fit between predicted and observed data improves (results are usually within a factor of three). When conservatism is deliberately introduced into the input pesticide parameters, substantial overprediction of runoff losses occur. Recommendations for future work to improve regulatory models include implementation of more sophisticated evapotranspiration routines, allowing for seasonal variation of various model parameters (such as curve numbers, crop cover, and Manning's surface roughness coefficients), better procedures for estimating site-specific degradation rates in surface and subsoils, and improved sorption routines.
Sensitivity analysis for validating expert opinion as to ideal data set criteria for transport modeling
Authors: Wolt Jeff , Singh Piyush , Cryer Steven , Lin Jim 
Published: March 2010

Abstract
Environmental fate modeling results are often used in risk assessment without adequately considering uncertainty in exposure predictions. Sensitivity analysis is fundamental to model validation and error prediction since sensitive model input parameters account for the largest variance in model prediction. Once identified, sensitive model input parameters can be used to propagate parametric uncertainty in numerical predictions. Output sensitivity to variation in input code sequences was investigated for the pesticide root zone model (PRZM 3) using Plackett-Burman analysis for six runoff and leaching data sets. The analysis utilized an incomplete block factorial design with even parameter weighting and uniform proportional input perturbation. Timing and duration of key period rainfall were assumed a priori to be dominant sensitive inputs. Thus, meteorological data were fixed, allowing identification of additional input components contributing to model sensitivity. Results validated expert modeler assumptions concerning parameters most critical for model validation. For leaching data sets, the application rate, soil bulk density (an indicator of available water-holding capacity), chemical partition coefficient, and pesticide degradation rates were commonly the most sensitive inputs. For runoff data sets, the in-crop runoff curve number was the most significant input governing pesticide loss in runoff and erosion flux. The chemical partition coefficient, soil and foliar decay rates, and soil bulk density were also common sensitive components for runoff predictions. These commonly observed sensitive components for runoff and leaching prediction need to be carefully considered in the design and conduct of relevant field studies, modeling assessment of such studies, and future improvements in algorithms for environmental transport modeling.
Using Monte Carlo techniques to judge model prediction accuracy: Validation of the pesticide root zone model 3.12
Authors: Warren-Hicks William , Carbone John P. , Havens Patrick L. 
Published: March 2010

Abstract
Individuals from the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) Environmental Model Validation Task Force (FEMVTF) Statistics Committee periodically met to discuss the mechanism for conducting an uncertainty analysis of Version 3.12 of the pesticide root zone model (PRZM 3.12) and to identify those model input parameters that most contribute to model prediction error. This activity was part of a larger project evaluating PRZM 3.12. The goal of the uncertainty analysis was to compare site-specific model predictions and field measurements using the variability in each as a basis of comparison. Monte Carlo analysis was used as an integral tool for judging the model's ability to predict accurately. The model was judged on how well it predicts measured values, taking into account the uncertainty in the model predictions. Monte Carlo analysis provides the tool for inferring model prediction uncertainty. We argue that this is a fairer test of the model than a simple one-to-one comparison between predictions and measurements. Because models are known to be imperfect predictors prior to running the model, the inaccuracy in model predictions should be considered when models are judged for their predictive ability. Otherwise, complex models can easily fail a validation test. Few complex models, such as PRZM 3.12, would pass a typical model validation exercise. This paper describes the approaches to the validation of PRZM 3.12 used by the committee and discusses issues in sampling distribution selection and appropriate statistics for interpreting the model validation results.
Distribution of polycyclic aromatic hydrocarbons in soils and terrestrial biota after a spill of crude oil in Trecate, Italy
Authors: Brandt Charles A. , Becker James M. , Porta Augusto 
Published: March 2010

AbstractEcological and human health exposures from soil-based petroleum-derived contaminants commonly are estimated by using soil-to-biota transfer factors that usually are based on octanol-water partitioning. Few studies of biota have been conducted in relation to spills of crude oils in terrestrial environments. After a large blowout of crude oil in northern Italy in 1994, the distribution of polycyclic aromatic hydrocarbons (PAHs) was examined over time and space in soils, uncultivated wild vegetation, insects, mice, and frogs in the area. Within two years of the blowout, PAH concentrations declined to background levels over much of the area where initial concentrations were within an order of magnitude above background, but had not declined to background in areas where starting concentrations exceeded background by two orders of magnitude. Octanol-water partitioning and extent of alkylation explained much of the variance in uptake of PAHs by plants and animals. The PAHs with lower octanol-water partition coefficients (KOWs) and higher-alkylated PAHs had higher biota-soil accumulation factors (BSAFs) than did high-KOW and unalkylated forms. The BSAFs for PAHs with higher KOWs were very low for plants, but much higher for animals, with frogs accumulating more of these compounds than other species.
Soil microbial toxicity of eight polycyclic aromatic compounds: Effects on nitrification, the genetic diversity of bacteria, and the total number of protozoans
Authors: Sverdrup Line Emilie , Ekelund Flemming , Krogh Paul Henning , Nielsen Torben , Johnsen Kaare 
Published: March 2010

Abstract
Eight polycyclic aromatic compounds (PACs) were tested for their toxic effect on the soil nitrification process, bacterial genetic diversity, and the total number of protozoans (naked amoebae and heterotrophic flagellates). After four weeks of exposure in a well-characterized agricultural soil, toxic effects were evaluated by comparison to uncontaminated control soils. All PACs affected the nitrification process, and the calculated no-observed-effect concentrations (NOECs) for nitrification were 79 mg/kg for pyrene, 24 mg/kg for fluoranthene, 26 mg/kg for phenanthrene, 72 mg/kg for fluorene, 23 mg/kg for carbazole, 22 mg/kg for dibenzothiophene, 75 mg/kg for dibenzofuran, and 1,100 mg/kg for acridine. For all substances but acridine, nitrification was the most sensitive of the three toxicity indicators evaluated. No effect of the tested substances on bacterial diversity was found, as measured by denaturant gradient gel electrophoresis. In general, only weak effects at very high concentrations were found for the protozoans. However, for acridine, protozoan numbers were reduced at lower concentrations than those that affected the nitrification process, that is, with a 5% reduction at 380 mg/kg. For effects on nitrification, toxicity (NOEC values) expressed as soil pore-water concentrations (log10(μmol/L)) showed a significant inverse relationship with lipophilicity (log octanol-water partition coefficient) of the substances (r2 = 0.69, p = 0.011, n = 8). This finding could indicate that the toxicity of substances similar to those tested might be predicted by a quantitative structure-activity relationship with lipophilicity as the predictor variable.
Effects of earthworm (Eisenia fetida) and wheat (Triticum aestivum) straw additions on selected properties of petroleum-contaminated soils
Authors: Callaham Mac A. , Stewart Arthur J. , Alarcón Clara , McMillen Sara J. 
Published: March 2010

AbstractCurrent bioremediation techniques for petroleum-contaminated soils are designed to remove contaminants as quickly and efficiently as possible, but not necessarily with postremediation soil biological quality as a primary objective. To test a simple postbioremediation technique, we added earthworms (Eisenia fetida) or wheat (Triticum aestivum) straw to petroleum land-farm soil and measured biological quality of the soil as responses in plant growth, soil respiration, and oil and grease (O&G) and total petroleum hydrocarbon (TPH) concentrations. Results indicated that plant growth was greater in earthworm-treated land-farm soil. Furthermore, addition of wheat straw resulted in greater total respiration in all soils tested (land-farm soil, noncontaminated reference soil, and a 1:1 mixture of land-farm and reference soils). We observed a 30% increase in soil respiration in straw-amended oily soil, whereas respiration increased by 246% in straw-amended reference soil. Much of the difference between oily and reference soils was attributable to higher basal respiration rates of nonamended oily soil compared to nonamended reference soil. Addition of earthworms resulted in greater total respiration of all soil and straw treatments except two (the land-farm and the 1:1 mixture soil treatments without straw). Straw and earthworm treatments did not affect O&G or TPH concentrations. Nevertheless, our findings that earthworm additions improved plant growth and that straw additions enhanced microbial activity in land-farm soil suggest that these treatments may be compatible with plant-based remediation techniques currently under evaluation in field trials, and could reduce the time required to restore soil ecosystem function.
Toxicity of methyl tert-butyl ether to plants (Avena sativa, Zea mays, Triticum aestivum, and Lactuca sativa)
Authors: An Youn-Joo , Kampbell Donald H. , McGill Mary E. 
Published: March 2010

Abstract
Influence of methyl tert-butyl ether (MTBE) on the germination of seeds and growth of seedling plants were studied in laboratory experiments. Test plants were wild oats (Avena sativa), sweet corn (Zea mays), wheat (Triticum aestivum), and lettuce (Lactuca sativa). Seed germination, shoot growth, and root growth of plants exposed to different concentrations of MTBE in a moist soil were examined. Seed germination and seedling growth in MTBE-contaminated soil were markedly reduced in all test plants. The median lethal concentration values for seed germination tests and the median effective concentration values for shoot or root growth were calculated. The values for lettuce, wild oats, wheat, and sweet corn were in the range of 18 to 91, 362 to 459, 432 to 751, and 672 to 964 mg MTBE/kg soil as dry weight, respectively. Lettuce was most sensitive to MTBE, followed (in order of decreasing sensitivity) by wild oats, wheat, and sweet corn. Because MTBE can be readily absorbed by plants due to its high solubility in water, plant growth was a more sensitive endpoint than seed germination. Shoot length was more reduced in MTBE-contaminated soil than was the root length, which indicated that MTBE might be transported within the plant from the roots to the shoots.
The further development of ionoregulatory measures as biomarkers of sensitivity and effect in fish species
Authors: Croke S. J. , McDonald D. G. 
Published: March 2010

Abstract
Extensive season-by-season sampling was used to establish the normal range of whole-body Na+ and Cl− and Na+ uptake in healthy populations of two fish species, rainbow trout, Oncorhynchus mykiss, and fathead minnow, Pimephales promelas, of known differences in sensitivity to ionoregulatory toxicants (low pH, trace metals). These data together with responses of both species to six different ionoregulatory challenge tests of increasing severity (mild handling, exposure to low Ca2+ water, epinephrine injection, net-confinement stress, exposure to copper, and osmotic shock) were evaluated for their potential as biomarkers of sensitivity and of effect of ionoregulatory toxicants. There were no obvious biomarkers of sensitivity in the ion measures themselves, but four of the six challenges (exposure to low Ca2+ water, epinephrine injection, exposure to copper, and osmotic shock) produced a significantly greater effect in the more sensitive of the two species, fathead minnow. Based on the responses of both species, this article makes a number of recommendations for the application of ion measures alone and in combination with challenge tests to the assessment of chronic effects in populations experiencing sublethal ionoregulatory stress.
Effect of ethinylestradiol on the reproduction and induction of vitellogenin and testis-ova in medaka (Oryzias latipes)
Authors: Seki Masanori , Yokota Hirofumi , Matsubara Haruki , Tsuruda Yukinari , Maeda Masanobu , Tadokoro Hiroshi , Kobayashi Kunio 
Published: March 2010

Abstract
Mature medaka (Oryzias latipes) were exposed to ethinylestradiol (EE2) at measured concentrations of 32.6, 63.9, 116, 261, and 488 ng/L for 21 d under flow-through conditions. Effects on reproductive success of the fish as well as on gonadal condition and vitellogenin (VTG) induction were assessed. A significant decrease in fecundity was observed only at the highest EE2 concentration, whereas hepatic VTG concentration in males was increased at concentrations of 63.9 ng/L and greater. In addition, an intersex condition (testis-ova) of the gonad was observed in male medaka exposed to EE2 concentrations of ≥63.9 ng/L. Overall, these results indicate that the lowest-observed-effect concentrations of EE2 based on reproduction versus induction of both VTG and testis-ova in the medaka were 488 and 63.9 ng/L, respectively. Thus, the physiological and histological measurements were approximately eightfold more responsive to the EE2 exposure than were overt reproductive effects. This suggests that the elevated VTG levels and testis-ova may not be definitely responsible for reproductive impairment of the fish.
Sequence analysis of choriogenin H gene of medaka (Oryzias latipes) and mRNA expression
Authors: Lee Chulwoo , Jeon Seong Hwan , Na Jin Gyun , Park Kwangsik 
Published: March 2010

Abstract
Zona radiata proteins of medaka (Oryzias latipes) consist of two major subunit groups, ZI-1,2 and ZI-3. The precursor of ZI-1,2, which is a glycoprotein with a molecular weight of 74,000 to 76,000 Da, is called choriogenin H, and the precursor of ZI-3, with a molecular weight of 49,000 Da, is called choriogenin L. The precursor proteins are synthesized in the liver in response to estrogen in sexually mature female medaka. However, they are also induced in the male medaka when fish are exposed to estrogenic chemicals. Therefore, choriogenin is known as a possible sensitive biomarker for endocrine disruption in fish. In this study, the choriogenin H cDNA sequence was reanalyzed and the genomic DNA sequence was newly analyzed. This was done for the selection of proper reverse transcription-polymerase chain reaction (RT-PCR) primers to measure the choriogenin mRNA induction by estrogenic chemicals. In the results, the full cDNA sequence was found to be 2,109 bp long and the size of the open reading frame (ORF) was found to be a total of 1,998 bp encoding 666 predicted amino acids, which was found to be different from previously reported cDNA sequence of medaka choriogenin. In the choriogenin H cDNA, a repetitive domain and a nonrepetitive domain were shown. Regarding the repetitive domain, seven complete repeats of the 45 bp of 5′-ccc cag tac cca tca aag cct cag ccc cct cag aat cct cag gtc-3′ encoding PQYPSKPQPPQNPQV were found. Medaka choriogenin H gene was found to possess seven exons and six introns, and the total length was 2,643 bp long. The seven repetitive nucleotide residues described above existed in exon 1, which was found to be 1,033 bp long. Based on the full sequence information, proper primers were synthesized for RT-PCR to detect choriogenin H mRNA induction in male and juvenile medaka by 17α-ethinylestradiol, and this type of measurement system was found to be effective as a simple tool for the screening of endocrine-disrupting chemicals.
Polychlorinated biphenyl toxicokinetics and P4501A responses in anadromous Arctic charr during winter emaciation
Authors: Jørgensen Even H. , Foshaug Hanne , Andersson Patrik , Burkow Ivan C , Jobling Malcolm 
Published: March 2010

Abstract
Polychlorinated biphenyl (PCB) toxicokinetics andhepaticP450 (CYP) 1A activities werestudied in wild anadromous Arctic charr (Salvelinus alpinus) during winter emaciation. The fish were captured as they returned from summer feeding in seawater and were held without food over winter. In September the fish were given a single, oral dose of either 0 (control), 0.1, 1, or 50 μg PCB/g fish. During winter a net loss of PCB occurred from the carcass (including gut), whereas net inputs and increases in concentrations of PCB in the liver and brain occurred with increases in brain PCB concentrations being up to 10-fold. Hepatic CYP1A activities were positively correlated with the PCB dose in October. In the fish given 1 mg PCB/kg fish in September, however, a 12-fold increase in CYP1A activity occurred from October to May. This increase in CYP1A activity was observed during a period in which the body burden of PCB decreased by 20%. These results demonstrate that interpretations of the CYP1A biomarker response must be made with caution. Overall, the findings point to potentiated risks of biological effects of PCB during periods of emaciation.
Aerobic biodegradation of aliphatic polyethoxylates: An 1H-nuclear magnetic resonance spectroscopy investigation
Authors: De Lazzari Alessandra , Pojana Giulio , Giacometti Andrea , Lucchini Vittorio , Marcomini Antonio 
Published: March 2010

Abstract
Aerobic biodegradation tests of three blends representative of the most commonly marketed aliphatic alcohol polyethoxylates (AE) and a commercial polyethylene glycols (PEG) mixture were run under standard test conditions (Organization for Economic Cooperation and Development, Paris, France [OECD] 301 E protocol). The test liquors were investigated using a 400-MHz proton-nuclear magnetic resonance (1H-NMR) spectrometer in order to elucidate the biodegradation mechanism. Diagnostic signals for both linear and branched AE homologs were identified by bidimensional homocorrelated spectroscopy (COSY) and by double quantum filter correlated spectroscopy (DQFCOSY). The 1H-NMR allowed individually monitoring the fate of the alkyl and polyethoxyl fragments of the parent compounds and distinguishing between oxidative and nonoxidative polyethoxyl depoly-merization, which could not be performed by other reported techniques such as high-peformance liquid chromatography (HPLC) or mass spectrometry (MS) or FAB spectroscopy. The AE biodegradation time profiles showed that under the test conditions, both alkyl and polyethoxyl chains of the linear and oxo-AE were biodegraded quite readily. The removal of the multibranched AE was slower when compared to that of linear and oxo-AE, while PEG exhibited a time profile characterized by a biodegradation rate significantly slower than that of PEG released by the microbial attack of linear and oxo-AE. In the case of linear AE, the alkyl chain was biodegraded much faster than the polyethoxyl chain, while in the case of oxo- and multibranched AE, both the alkyl and the polyethoxyl chains were biodegraded at similar rates.
Use of anodic stripping voltammetry in predicting toxicity of copper in river water
Authors: Wang Zijian , Huang Shengbiao , Liu Qing 
Published: March 2010

AbstractThe labile concentration and toxicity of Cu as influenced by alkalinity and different concentrations of ethylenediaminetetraacetic acid (EDTA) and naturally derived fulvic acid (FA) were determined by bioassays carried out in the culture media for Daphnia magna (D. magna). The labile concentration of Cu was obtained by differential pulse anodic stripping voltammetry with a double-acidification method (DAM-DPASV). Changes in water alkalinity did not affect the labile concentration of Cu, but increase in alkalinity did reduce the mortality of D. magna. In the presence of EDTA and FA, both labile concentration of Cu and mortality were reduced. By excluding Cu-carbonate complexes from the labile concentration, a bioavailable concentration of Cu ([Cu*]) was obtained and was used to predict the acute toxicity of Cu on D. magna. For natural waters, the labile concentration of Cu was measured by DAM-DPASV, and [Cu*] was calculated using MINTEQ A2 software (developed by the U.S. Environmental Protection Agency) based on the anion composition of waters. This procedure was tested for waters and sediment elutriates sampled from the Le An River (Jiangxi Province, China) that were severely polluted by the discharges from a copper mine. The results showed that [Cu*] was a good indicator for Cu toxicity and could be used under field conditions.