bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polymerase chain reaction as a tool for developing stress protein probes
Authors: Cochrane Bruce J. , Mattley Yvette D. , Snell Terry W. 
Published: March 2010

Abstract
Because of the high degree of evolutionary conservation of stress proteins, potential exists for the development of nucleic acid probes from particular species that could be used to monitor stress related changes in mRNA abundance The polymerase chain reaction (PCR) is a powerful tool that can be applied to the generation of these probes, provided that primer sequences can be identified that specifically amplify sequences of interest from a wide variety of organisms We identified such sequences from multiple alignments of published chaperomn and stress-70 sequences, and tested their ability to amplify appro priately sized fragments from genomic DNA from a variety of vertebrates and invertebrates Although no primer pair could be used successfully with all species, we were able to derive specific products from most species by testing different pairs One primer pair for chaperomn proved particularly useful Products were obtained from all tested species, and with a single exception (human), these primers appeared to amplify a single copy sequence We determined the nucleotide sequence of the product obtained from the rotifer Brachionus plicatilis and determined by phylogenetic analysis of the inferred protein product that the product obtained is most likely derived from a rotifer DNA template Finally, we show that this product can be used to detect changes in abundance of homologous mRNA in heat stressed rotifers We suggest that this approach may prove useful not only in the context of development of hybridization probes for stress proteins, but also for designing peptides to be used for generation of specific antibodies, as well as for obtaining probes for other stress regulated genes that are less conserved than the classical stress proteins
Sampling the hudson river estuary for pcbs using multiplate artificial substrate samplers and congener-specific gas chromatography in 1991
Authors: Bush Brian , Wood Lindsay , Madrigal E. Cheryl , Dzurica Susan 
Published: March 2010

Abstract
During the summer of 1991, multiplate artificial substrate samplers were deployed at five locations in the Hudson River from Troy to Poughkeepsie, New York The sedimentary material that collected on these plates was fractionated and analyzed using a congener specific method for PCB content The results were compared intrasite, intersite, and across time We found no difference between the PCB congener distribution patterns in the coarse and fine fractions, as determined by linear regression We also found little evidence of intersite differentiation – we found no discernible difference in PCB congener distribution, but we did find a difference in magnitude The 1991 results were then compared to the results from a previous study conducted from 1977 to 1985 We found that over the studied 120 km stretch of the river there has been a 3 7 ± 1 2% per annum decline in PCB multiplate residue since 1983
Toxicity and irreversible binding of two DDT metabolites —3-methylsulfonyl-DDE and o,p'-DDD-in adrenal interrenal cells in birds
Authors: Jonsson C.-J. , Lund B.O. , Brunstrom B. , Brand I. 
Published: March 2010

AbstractThe toxicity and the metabolism dependent irreversible binding of the lipophilic DDT metabolites 3-methylsulfonyl DDE (MeSO2 DDE) and o,p DDD in the adrenal gland of the chicken were examined As determined by histopathology, vacuolar degeneration and pycnosis of adrenal interrenal cells occurred 4 d after injection of a single dose of either compound (0 25 mmol/kg, 80–100 mg/kg body weight) to 6-d old chicken In addition, o,p DDD, but not MeSO2 DDE, induced fatty degeneration of the liver According to autoradiography, irreversibly bound radioactivity was present in the interrenal cells after injection of the 14C-labeled compounds into the air sacs of eggs Both DDT metabolites were also irreversibly bound to protein after incubation with adrenal 300 g supernatant in vitro, with apparent Km values of 2 0 and 8 3 μM for MeSO2 DDE and o,p DDD, respectively The irreversible binding in vitro was inhibited by metyrapone, SKF 525A, and carbon monoxide, suggest ing a cytochrome P450-dependent metabolic activation to reactive intermediates Addition of glutathione to the incubations reduced the irreversible binding of MeSO2-[14C]DDE significantly, whereas the irreversible binding of o,p [14C]DDD remained un changed The results indicate that MeSO2-DDE and o,p DDD are adrenocorticolytic following an adrenal P450-dependent met abolic activation in the chicken Experiments with embryonated eggs from common eider and domestic duck demonstrated that MeSO2 DDE and o,p DDD are also metabolically activated and irreversibly bound to adrenal tissue in embryos of these species
Chronic toxicity of waterborne thiocyanate to the fathead minnow (pimephales promelas): A partial life-cycle study
Authors: Lanno Roman P. , Dixon D. George 
Published: March 2010

Abstract
Juvenile fathead minnows (Pimephales promelas) were exposed to thiocyanate (SCN−) concentrations of 0, 1.1, 7.3, 16.6, or 32.6 mg/L for 124 d while monitoring growth, physiological, reproductive, and histological parameters. The NOEC for decreased egg production, increased time to first spawn, and development of overt goiter was 1.1 mg/L, whereas the LOEC for these parameters was 7.3 mg/L. Histological changes in thyroidal tissue were the most sensitive parameter observed, with an LOEC of 1.1 mg/L. Fish exposed to 16.6 or 32.6 mg SCN−/L neither completed development of secondary sexual characteristics nor spawned. The LOEC for decreased growth and hematocrit was 32.6 mg/L. SCN− accumulated in the plasma of fish exposed to 16.6 and 32.6 mg/L, with BCFs of 2.7 and 13.8, respectively. Development and mortality of embryos and larvae to 3 d post-hatch were also monitored in eggs spawned by adults exposed to 0 or 1.1 mg SCN−1/L and subsequently incubated and hatched at 0, 1.1, 7.3, 16.6, or 32.6 mg/L. Eggs spawned by adults exposed to 1.1 mg SCN−1/L exhibited increased percentage of eyeup and hatch, while decreasing time to hatch and mortality. There were no effects of SCN− concentration during incubation on egg viability. After the 124-d exposure, adults were transferred to SCN−-free water for 30 d. Insufficient numbers of adults were available from groups exposed to 32.6 mg/L to be included in the recovery study. Eggs were spawned by all groups during the recovery period, regardless of the SCN− preexposure level, although time to first spawn increased with preexposure concentration.
Feeding selectivity and assimilation of PAH and PCB in Diporeia spp.
Authors: Harkey Gail A. , Lydy Michael J. , Kukkonen Jussi , Landrum Peter F. 
Published: March 2010

Abstract
A series of experiments were conducted to estimate assimilation efficiencies of two hydrophobic organic contaminants and the influence of particle sizes on the selective sediment ingester, Diporeia spp. Florissant soil was divided into particle-size fractions consisting of 0 to 63 μm, 0 to 20 μm, and 20 to 63 μm and dosed with radiolabeled 2,2′,4,4′,5,5′-hexachlorobiphenyl (HCBP) and/or benzo[a]pyrene (BaP) to which animals were exposed for individual assays. At the end of timed exposure intervals, individual Diporeia and any fecal pellets they produced were removed from the sediment and analyzed for contaminant content. Assimilation efficiency was estimated via a selectivity index based on organic carbon. Assimilation efficiency of BaP (5.6–32.7%) was comparable to previous studies. However, HCBP did not correlate with organic carbon over a range of particle sizes. Accumulation of both contaminants was greatest when animals were exposed to the 20- to 63-μm size fraction, suggesting that Diporeia selectively fed within this particle-size range. Accumulation of HCBP was consistently greater than BaP in all dual-labeled assays, suggesting a greater bioavailability of the PCB to Diporeia. Sediment analysis indicated that BaP and HCBP were associated with different particle-size fractions possessing different amounts of organic carbon, with BaP having the greater tendency to associate with TOC.
Comparative cytotoxicity of chlorophenols to cultured fish cells
Authors: Saito Hotaka , Shigeoka Tadayoshi 
Published: March 2010

Abstract
In vitro cytotoxicity of chlorophenols to Cyprinus carpio brain (CCB) cells derived from carp and Oryzias latipes fin (OLF 136) cells derived from medaka was examined with the neutral red (3 amino 7 dimethylamino 2-methylphenazine hydrochloride) incorporation assay Results were compared with previous cytotoxicity data of chlorophenols to goldfish (Carassius auratus) scale (GFS) cells derived from the goldfish There were excellent correlations between the 24 h NR50 values of chlorophenols toward the three kinds of cells (r2 &gt; 0 94)
Spatial and temporal variability in metal bioavailability and toxicity of sediment from hamilton harbour, lake ontario
Authors: Krantzberg Gail 
Published: March 2010

Abstract
Trace metals in sediment from nearshore urban and industrialized centres of the Great Lakes are frequently at concentrations well above geological background values Total metal content in sediment, however, is a weak predictor of sediment toxicity This study examined the bioavailability of metals from Hamilton Harbour in Lake Ontario and considered variability in metal forms on a temporal basis Sediment from regions within Hamilton Harbour is highly contaminated with metals, nevertheless, not all metal contaminated sites were toxic to test organisms Most sediment did elicit sublethal and/or lethal responses in bioassay organisms Metal bioavailability, as measured by weak acid extractions, metal bioaccumulation by fathead minnows, and sediment toxicity, was greater in sediment collected in the fall as compared to sediment collected in the spring Results of analyses of tissue residues in test organisms and the reduced toxicity observed in sediment collected from some stations in the spring as compared to the fall implicate trace metals and sediment oxygen demand as contributing to sediment toxicity The suitability for colonization by benthic invertebrates of sediment in some areas of Hamilton Harbour appears to be limited by both contaminants and high sediment oxygen demand Improving the oxygen regime of the harbour should result in improvements in the benthic invertebrate community directly, by providing a suitable oxygen regime for organisms less tolerant of temporal anoxia and indirectly by decreasing metal bioavailability, possibly through the co precipitation of trace metals with iron and manganese hydroxides
Factors affecting chemical and biological reduction of hexavalent chromium in soil
Authors: Losi M.E. , Amrhein C. , Frankenberger W.T. 
Published: March 2010

Abstract
Hexavalent chromium [Cr(VI)] is a common environmental pollutant that is mobile in soils and is a known mutagen The trivalent form [Cr(III)] has no known mutagenic properties and is highly insoluble and immobile above pH 5 5 Reduction to the trivalent state thus represents an effective mechanism for detoxification and immobilization of Cr(VI) in soil/water systems In this study, we conducted experiments to examine various parameters involving aerobic reduction of Cr(VI) in a field soil We found that organic matter content, bioactivity, and oxygen status were important factors Under optimum conditions, the soil reduced 96% of added Cr(VI) under aerobic, field moist conditions The pH of the system was shown to have little effect Both biological and nonbiological processes were influential, and, of 20 chromate resistant bacterial cultures isolated from soils, 9 were found to actively reduce Cr(VI) to Cr(III) in liquid media Our study suggests that organic amended soils can readily reduce Cr(VI) and could promote excellent removal efficiency either as a primary treatment technique, or in conjunction with bioreactor type wastewater treatment systems
Mutagenicity screening of reaction products from the enzyme-catalyzed oxidation of phenolic pollutants
Authors: Massey I. Joanna , Aitken Michael D. , Ball Louise M. , Heck Phillip E. 
Published: March 2010

Abstract
Phenol-oxidizing enzymes such as peroxidases, laccases, and mushroom polyphenol oxidase are capable of catalyzing the oxidation of a wide range of phenolic pollutants. Although the use of these enzymes in waste-treatment applications has been proposed by a number of investigators, little information exists on the toxicological characteristics of the oxidation products. The enzymes chloroperoxidase, horseradish peroxidase, lignin peroxidase, and mushroom polyphenol oxidase were used in this study to catalyze the oxidation of phenol, several mono-substituted phenols, and pentachlorophenol. Seventeen reaction mixtures representing selected combinations of enzyme and parent phenol were subjected to mutagenicity screening using the Ames Salmonella typhimurium plate incorporation assay; five selected mixtures were also incubated with the S9 microsomal preparation to detect the possible presence of promutagens. The majority of reaction mixtures tested were not directly mutagenic, and none of those tested with S9 gave a positive response. Such lack of mutagenicity of enzymatic oxidation products provides encouragement for establishing the feasibility of enzyme-catalyzed oxidation as a waste-treatment process. The only positive responses were obtained with reaction products from the lignin peroxidase–catalyzed oxidation of 2-nitrophenol and 4-nitrophenol. Clear positive responses were observed when strain TA100 was incubated with 2-nitrophenol reaction-product mixtures, and when strain TA98 was incubated with the 4-nitrophenol reaction mixture. Additionally, 2,4-dinitrophenol was identified as a reaction product from 4-nitrophenol, and preliminary evidence indicates that both 2,4- and 2,6-dinitrophenol are produced from the oxidation of 2-nitrophenol. Possible mechanisms by which these nitration reactions occur are discussed.
Toxicological significance of non-, mono- and di-ortho-substituted polychlorinated biphenyls in oysters from galveston and tampa bays
Authors: Sericano Jose L. , Wade Terry L. , Brooks James M. , Safe Stephen H. 
Published: March 2010

Abstract
Concentrations of non ortho (77, 126, and 169), mono-ortho (105 and 118) and di-ortho (128 and 138) substituted PCB congeners were measured in oysters from Galveston and Tampa bays, and reported toxic equivalent factors were used to assess their toxicity Most of the relative toxicity encountered in the oysters analyzed during this study was due to the presence of planar non-ortho-PCBs (53 8–94 3%), particularly congener 126 In contrast, the contribution of di-ortho-substituted PCB congeners to the total relative toxicity of the samples was negligible (&lt;1%) On average, the contribution of each of these non, mono, and di ortho substituted PCB congeners to the total toxicity encountered in oysters from Galveston and Tampa bays were 126 &gt; 118 ≥ 169 ≥ 105 &gt; 77 » 138 &gt; 128 and 126 &gt; 118 &gt; 169 ≥ 77 &gt; 105 » 138 &gt; 128, respectively Based on the reported lower clearance rates of non ortho and mono ortho-substituted PCB congeners compared to other congeners within the same chlorination level, contaminated oysters that are depurated in clean environments will lower their total PCB concentrations, but their original toxicity may not be proportionally reduced
The effect of exposure to 1,2,4,5-tetrachlorobenzene and the relationship between toxicant and oxygen uptake in rainbow trout (Oncorhynchus mykiss) during exercise
Authors: Brauner C.J. , Randall D.J. , Neuman J.F. , Thurston R.V. 
Published: March 2010

Abstract
These studies were designed to investigate the relationship between the initial uptake of a model toxicant, 1,2,4,5-tetrachlorobenzene (TCB), and the rate of oxygen consumption (MO2) in trout during exercise. There was no effect of environmental TCB concentrations ([TCB]) on the MO2 of resting or exercising adult rainbow trout, and body accumulations of the toxicant did not affect the maximal aerobic swimming velocity attained by juvenile rainbow trout. Rainbow trout were exposed to TCB for 1 h while swimming at different velocities and the [TCB] was measured in plasma and 11 other tissues. Tissue TCB concentrations were found to be extremely variable despite similar exposure conditions, likely due to differences in tissue lipid content. No one tissue was representative of body burden, but tissue TCB delivery appears to be directly related to the [TCB] in the plasma because at different swimming velocities the plasma:tissue TCB ratios remained constant despite regional changes in blood flow. After 2 h of TCB exposure, [TCB] in the plasma was equal to whole-body [TCB]; however, this relationship broke down after 6 h. Thus, whole-body TCB concentrations can only be obtained through direct measurement. There was a highly significant relationship (r2 = 0.79) between MO2 and TCB uptake rate during initial toxicant exposure in adult rainbow trout forced to swim over a large proportion of its aerobic potential. Thus, toxicant uptake in fish may be estimated based upon MO2, which can be measured or can be obtained from the literature.
Scaling spatial predictability: An approach to multi-resolution modeling
Authors: Maxwell Thomas , Costanza Robert 
Published: March 2010

Abstract
We have investigated the dependence of spatial predictability, a statistical measure of the reduction in uncertainty about one spatial variable that can be gained by knowledge of another, on the spatial resolution (Rs) of the variables. While increasing resolution provides more descriptive information about the patterns in data, it also increases the difficulty of accurately modeling those patterns. By examining the variation of spatial predictability with Rs in a number of case studies, we have proposed the existence of an “optimal” Rs for specific studies, which balances these two factors. We analyzed land-use data by resampling map data sets at several different spatial resolutions and measuring predictability at each. Spatial auto-predictability (Pa) is the reduction in uncertainty about the state of a cell in a map given knowledge of the state of adjacent cells in that map, and spatial cross-predictability (Pc) is the reduction in uncertainty about the state of a cell in a map given knowledge of the state of corresponding cells in other maps. The Pa is a measure of the internal pattern in the data, whereas Pc is a measure of the ability of some “model” to represent the transition from one map to another. We found a strong linear relationship between the log of Pd and the log of Rs (measured as the number of cells per square kilometer). While Pa generally increases with increasing Rs (because more information is being included), Pc generally falls or remains stable (because it is easier to model aggregate results than fine-grained ones). Thus, one can define an “optimal” Rs a particular modeling problem that balances the benefit in terms of increasing data predictability (measured by Pa) as one increases resolution, with the cost of decreasing facility of modeling the temporal dynamics (measured by Pc).
Chemical characterization of sediments and pore water from the upper Clark Fork river and milltown reservoir, Montana
Authors: Brumbaugb W.G. , Ingersoll C.G. , Kemble N.E. , May T.W. , Zajicek J.L. 
Published: March 2010

AbstractThe upper Clark Fork River basin in western Montana is widely contaminated by metals from past mining, milling, and smelting activities As part of a comprehensive ecological risk assessment for the upper Clark Fork River, we measured physical and chemical characteristics of surficial sediment samples that were collected from depositional zones for subsequent toxicity evaluations Sampling stations included five locations along the upper 200 km of the river, six locations in or near Milltown Reservoir (about 205 km from the river origin), and two tributary reference sites Concentrations of As, Cd, Cu, Mn, Pb, and Zn decreased from the upper stations to the downstream stations in the Clark Fork River but then increased in all Milltown Reservoir stations to levels similar to uppermost river stations Large percentages (50 to 90%) of the total Cd, Cu, Pb, and Zn were extractable by dilute (3 n) HCl for all samples Copper and zinc accounted for greater than 95% of extractable metals on a molar basis Acid-volatile sulfide (AVS) concentrations were typically moderate (0 6 to 23 μmol/g) in grab sediment samples and appeared to regulate dissolved (filterable) concentrations of Cd, Cu, and Zn in sediment pore waters Acid volatile sulfide is important in controlling metal solubility in the depositional areas of the Clark Fork River and should be monitored in any future studies Spatial variability within a sampling station was high for Cu, Zn, and AVS, therefore, the potential for toxicity to sediment dwelling organisms may be highly localized
Modeling toxicity due to intermittent exposure of rainbow trout and common shiners to monochloramine
Authors: Meyer Joseph S. , Gulley David D. , Goodrich Mark S. , Szmania Donald C. , Brooks Arthur S. 
Published: March 2010

Abstract
We evaluated the ability of three mathematical models to predict toxicity to common shiners and rainbow trout during intermittent (pulsed) exposures to monochloramine, based on data from continuous-exposure toxicity tests. If a power term for the exposure-water concentration was included in the models, a concentration × time (Cxt) model and the Mancini uptake-depuration model predicted pulse LC50s to within ±50% of the observed pulse LC50s, for the first four pulses in toxicity tests with 2-h pulse/22-h recovery cycles. Beyond the fourth pulse cycle, though, the pulse LC50s predicted using the Cxt model appeared to diverge considerably from the trend of the experimental pulse LC50s, partly because this model does not predict an incipient lethal level (CILL) for either continuous or intermittent exposures. The Mancini model predicted the CILL moderately well in the common shiner intermittent-exposure test but not in the rainbow trout intermittent-exposure test. The Breck three-dimensional damage-repair model did not predict pulse LC50 or CILL values as well as did the other two models, probably because not enough partial-mortality data were available to parameterize the model adequately. Although the underlying processes appear to be more complex than what these simple models assume, the models may still be adequate for use in regulating a few pulse discharges of monochloramine.
Multivariate QSBR modeling of biodehalogenation half-lives of halogenated aliphatic hydrocarbons
Authors: Eriksson Lennart , Jonsson Jörgen , Tysklind Mats 
Published: March 2010

Abstract
Multivariate quantitative structure-biodegradability relationships (QSBRs) were developed for a series of 20 halogenated aliphatic hydrocarbons investigated for their microbial biodehalogenation (expressed as half-lives). These QSBRs are based on a battery of quantum-chemical descriptors and the use of the multivariate data analytical techniques principal component analysis (PCA) and partial least-squares projections to latent structures (PLS). The developed models are introduced and discussed from a multivariate data analytical perspective, and much emphasis is placed on the elucidation of the predictive significance of the developed relationships. It is shown that multivariate QSBRs can be formulated for three sets of microorganisms and compounds. These QSBRs can be used to predict biodehalogenation properties for yet untested compounds.