bluuebunny/crossref_metadata_2025_split huggingface dataset:
Glycosidation of chlorophenols by Lemna minor
Authors: Day James A. , Saunders F. Michael 
Published: March 2005

Abstract
Metabolic fate of xenobiotics in plant tissues has an important role in the ultimate fate of these compounds in natural and engineered systems. Chlorophenols are an important class of xenobiotics used in a variety of biocides and have been shown to be resistant to microbial degradation. Three chlorophenyl glycosides were extracted from tissues of Lemna minor exposed to 2,4-dichlorophenol (DCP). The products were identified as 2,4-dichlorophenyl-β-D-glucopyranoside (DCPG), 2,4-dichlorophenyl-β-D-(6-O-malonyl)-glucopyranoside (DCPMG) and 2,4-dichlorophenyl-β-D-glucopyranosyl-(6→1)-β-D-apiofuranoside (DCPAG). Identification was based on reverse phase retention (C18), electrospray mass spectra collected in negative and positive mode (ESI-NEG and ESI-POS, respectively), and nuclear magnetic resonance (NMR) spectra comparisons to reference materials synthesized in the laboratory. Liquid chromatography-mass spectrometry (LC-MS) analysis of plants exposed to 2,4,5-trichlorophenol (TCP) formed analogous compounds: 2,4,5-trichlorophenyl-β-D-glucopyranoside (TCPG), 2,4,5-trichlorophenyl-β-D-(6-O-malonyl)-glucopyranoside (TCPMG) and 2,4,5-trichlorophenyl-β-D-glucopyranosyl-(6→1)-β-D-apiofuranoside (TCPAG). Enzyme catalyzed hydrolysis with β-glucosidase was ineffective in releasing the β-glucosides with chemical modifications at C6. Presence of these glucoconjugates confirmed that L. minor was capable of xenobiotic uptake and transformation. Identification of these products suggested that chlorophenols were incorporated into vacuoles and cell walls of L. minor.
Use of vegetative furrows to mitigate copper loads and soil loss in runoff from polyethylene (plastic) mulch vegetable production systems
Authors: Rice Pamela J. , Harman-Fetcho Jennifer A. , Teasdale John R. , Sadeghi Ali M. , McConnell Laura L. , Coffman C. Benjamin , Herbert Rachel R. , Heighton Lynne P. , Hapeman Cathleen J. 
Published: March 2005

Abstract
The transport of runoff with high copper concentrations and sediment loads into adjacent surface waters can have adverse effects on nontarget organisms as a result of increased turbidity and degraded water quality. Runoff from vegetable production utilizing polyethylene mulch can contain up to 35% of applied copper, a widely used fungicide/bactericide that has adverse effects on aquatic organisms. Copper is primarily transported in runoff with suspended particulates; therefore, implementation of management practices that minimize soil erosion will reduce copper loads. Replacing bare-soil furrows with furrows planted in rye (Secale cereale) significantly improved the sustainability of vegetable production with polyethylene mulch and reduced the potential environmental impact of this management practice. Vegetative furrows decreased runoff volume by &gt;40% and soil erosion by &gt;80%. Copper loads with runoff were reduced by 72% in 2001, primarily as a result of reduced soil erosion since more than 88% of the total copper loads were transported in runoff with suspended soil particulates. Tomato yields in both years were similar between the polyethylene mulch plots containing either bare-soil or vegetative furrows. Replacing bare-soil furrows with vegetative furrows greatly reduces the effects of sediments and agrochemicals on sensitive ecosystems while maintaining crop yields.
Phase distribution of synthetic pyrethroids in runoff and stream water
Authors: Liu Weiping , Gan Jay J. , Lee Sangjin , Kabashima John N. 
Published: March 2005

Abstract
Synthetic pyrethroids (SPs) are a group of hydrophobic compounds with significant aquatic toxicity. Their strong affinity to suspended solids and humic materials suggests that SPs in natural surface water are distributed in solid-adsorbed, dissolved organic matter (DOM)-adsorbed, and freely dissolved phases. The freely dissolved phase is of particular importance because of its mobility and bioavailability. In the present study, we used solid-phase microextraction to detect the freely dissolved phase, and we evaluated the phase distribution of bifenthrin and permethrin in stream and runoff waters. In stream water, most SPs were associated with the suspended solids and, to a lesser extent, with DOM. The freely dissolved phase contributed only 0.4% to 1.0%. In runoff effluents, the freely dissolved concentration was 10% to 27% of the overall concentration. The predominant partitioning into the adsorbed phases implies that the toxicity of SPs in surface water is reduced because of decreased bioavailability. This also suggests that monitoring protocols that do not selectively define the freely dissolved phase can lead to significant overestimation of toxicity or water-quality impacts by SPs.
Anaerobic transformation of compounds of technical toxaphene. 2. Fate of compounds lacking geminal chlorine atoms
Authors: Ruppe Steffen , Neumann Anke , Braekevelt Eric , Tomy Gregg T. , Stern Gary A. , Maruya Keith A. , Vetter Walter 
Published: March 2005

Abstract
The major toxaphene metabolites in sediment and soils (2-exo,3-endo,6-exo,8,9,10-hexachlorobornane [B6-923] and2-endo,3-exo,5-endo,6-exo,8,9,10-heptachlorobornane [B7-1001]) were incubated with the isolated gram-negative bacterium Dehalospirillum multivorans. Within 14 d, biotransformation of B7-1001 was nearly quantitative, resulting in two penta- and six hex-achlorobornanes, as well as one unsaturated hexachloro compound of technical toxaphene. The major transformation product (˜50% of all metabolites) was identified as 2-exo,3-endo,5-exo,8,9,10-hexachlorobornane (B6-903). Abiotic dehydrochlorination of B7-1001 with methanolic KOH resulted in the formation and subsequent identification of the lone unsaturated compound as 2,5-endo,6-exo,8,9,10-hexachloroborn-2-ene. Thus, dehydrochlorination was found to be a minor process of the anaerobic transformation of toxaphene. Biotransformation of 70% of amended B6-923 within 14 d demonstrated that reductive dechlorination was not exclusively associated with geminal Cl atoms, as previously suggested. Three pentachlorobornanes were identified as transformation products, one of which was identical with a transformation product of B7-1001. This commonality unequivocally proves this metabolite to be 2-exo,3-endo,8,9,10-pentachlorobornane. Fifteen previously unknown metabolites of B6-923, B7-1001, and other toxaphene compounds identified in this study were detected in sediment from Lake Ontario (Canada), underscoring the importance of microbial toxaphene transformation in natural, aquatic environments.
Toxicokinetics of sediment-associated polybrominated diphenylethers (flame retardants) in benthic invertebrates (Lumbriculus variegatus, oligochaeta)
Authors: Leppänen Matti T. , Kukkonen Jussi V. K. 
Published: March 2005

Abstract
Polybrominated diphenylethers (PBDEs) are ubiquitous environmental contaminants showing rapid temporal increase in some sample types. The compounds are known to biomagnify in aquatic food webs and are assumed to archive into sediments and soils. Currently, no direct evidence indicates whether sediment-associated PBDEs are available for biota. The aim of the present study was to explore the uptake and elimination of two common congeners (47 and 99) in sediment-inhabiting invertebrates to shed light on possible bioavailability of sediment-associated PBDEs. Two clean lake sediments were spiked with environmentally relevant concentrations of 14C-labeled tetra- and pentabromo diphenylether, and oligochaetes (Lumbriculus variegatus) were exposed for three or four weeks to allow kinetic accumulation calculations. Subsequent depuration tests were performed after three weeks of exposure to obtain depuration rates. Both congeners were clearly bioavailable, and only slight differences in steady-state tissue concentrations were found between the four sediment-ingesting oligochaete treatments (biota sediment accumulation factors [BSAFs], 3.0–3.7). The tetrabromo diphenylether-exposed oligochaetes that did not ingest sediment had clearly lower influx rates (0.1 vs 1–3 nmol h-1) than sediment-ingesting worms. Also, the estimated BSAF (1.8) was statistically different from that of the sediment-ingesting oligochaetes. These findings support the significance of feeding behavior in bioaccumulation of very hydrophobic organic contaminants. Depuration of both congeners was biphasic, indicating two kinetically different compartments in L. variegatus. Compartment A made up 73 to 92% of total radioactivity in tissues and had relatively fast depuration rates (half-lives, 10.5–47.5 h); the smaller compartment B had very slow depuration rates. No significant biotransformation of PBDEs was evident. The present study clearly demonstrates that the sediment-associated PBDEs, like other hydrophobic organic contaminants of environmental concern, are not totally sequestered from sediment-inhabiting oligochaetes and are subject to trophic transfer.
Mercury concentrations in fish from forest harvesting and fire-impacted Canadian Boreal lakes compared using stable isotopes of nitrogen
Authors: Garcia Edenise , Carignan Richard 
Published: March 2005

Abstract
otal mercury (Hg)concentration was determined in several piscivorous and nonpiscivorous species of fish from 38 drainage lakes with clear-cut, burnt, or undisturbed catchments located in the Canadian Boreal Shield. Mercury concentrations increased with increasing fish trophic position as estimated using stable isotopes of nitrogen (N; r2 = 0.52, 0.49, and 0.30 for cut, reference, and burnt lakes, respectively; p &lt; 0.01). Mercury biomagnification per %‰ δ15N varied from 22 to 29% in the three groups of lakes. Mercury availability to organisms at the base of the food chain in lakes with cut catchments was higher than that in reference lakes. In cut lakes, Hg concentrations in fish were significantly related to ratio of the clear-cut area to lake area (or lake volume; r = +0.82 and +0.74, respectively, p &lt; 0.01). Both impact ratios were, in turn, significantly correlated with dissolved organic carbon. These findings suggest that differential loading of organic matter–bound Hg to lakes can affect Hg cycling. In addition, Hg concentrations exceeded the advisory limit for human consumption (0.5 μg/g wet wt) from the World Health Organization in all top predatory species (northern pike, walleye, and burbot) found in cut and in two partially burnt lakes. Thus, high Hg concentrations in fish from forest-harvested and partially burnt lakes may reflect increased exposure to Hg relative to that in lakes not having these watershed disturbances.
Comparison of different microbial bioassays to assess metal-contaminated soils
Authors: Tandy Susan , Barbosa Vera , Tye Andy , Preston Sara , Paton Graeme , Zhang Hao , McGrath Steve 
Published: March 2005

Abstract
These experiments compared the sensitivity of four different types of bioassay over time after five metals were added to a wide range of soils at the maximum concentrations in the European Union Sewage Sludge Directive. Three were chronic assays (most probable number of Rhizobium leguminosarum, soil microbial C and Biolog substrate utilization). The fourth bioassay, an acute biosensor, employed a lux-marked luminescent bacterium (Escherichia coli) in the soil pore water. Five metals were added to 23 different soils as a mixture at Zn = 300, Cd = 3, Pb = 300, Cu = 135, and Ni = 75 mg/kg as nitrate salts and compared with unamended controls. Zinc and Cu were the metals most likely to be toxic at the concentrations used here. In the case of Rhizobium, the number of cells in soil was not affected after 11d; however, by 818 d the numbers had decreased by four orders of magnitude with increasing concentrations of Zn and Cu in soil solution. Microbial biomass also was not affected after 11d, but significantly decreased with increased Zn (p &lt; 0.001) and Cu (p &lt; 0.01) in soil solution after 818 d. Toxicity to the soil microbial biomass increased with time, whereas the toxicity to the biosensor remained the same. Biolog substrate utilization profiles were not responsive to the concentrations used here.
Field exposure of frog embryos and tadpoles along a pollution gradient in the Fox River and Green Bay ecosystem in Wisconsin, USA
Authors: Karasov William H. , Jung Robin E. , Vanden Langenberg Susan , Bergeson Tara L. E. 
Published: March 2005

Abstract
We raised embryos and tadpoles of green frogs (Rana clamitans melanota) and leopard frogs (R. pipiens) in situ along a contamination gradient in the Fox River/Green Bay ecosystem (WI, USA). Differences in exposure were reflected by significant positive regressions between concentrations in sediment and in frogs of polychlorinated biphenyl (PCB) congeners and some heavy metals (Cd, Cr, and Pb), which could have predictive value for estimating exposure of amphibians to contaminants in this ecosystem and, perhaps, in others. On average, non-ortho-substituted coplanar PCBs made up a very small percentage (average, 0.2%) of the PCB congeners in all samples analyzed, with larger fractions accounted for by mono- and di-ortho congeners (average, 19%) and routine congeners (average, 81%). Hatchability of frog embryo batches and anuran species richness at the sites were negatively correlated with level of contamination, but tadpole growth and survival were not. Sediment and tissue levels of PCBs and metals generally were correlated with each other, confounding the association of effects on frogs with any particular contaminant. It is also plausible that high levels of un-ionized ammonia (NH3) reduced hatching success of green frog, but not leopard frog, embryos in the field enclosures. Other environmental factors that were present but unmeasured in the field, such as ultraviolet-B radiation as well as water flow and level fluctuations, might have caused differences in hatching success at the field sites.
Effects of perchlorate exposure on resting metabolism, peak metabolism, and thyroid function in the prairie vole (Microtus ochrogaster)
Authors: Isanhart John P. , McNabb F. M. Anne , Smith Philip N. 
Published: March 2005

Abstract
Perchlorate, the oxidizer component in most solid rocket propellant formulations, is known to inhibit the uptake of iodide into the thyroid gland, thereby reducing production of the thyroid hormones, triiodothyronine and thyroxine (T4). Thyroid hormones regulate metabolism in endothermic organisms and are responsible for maintenance of homeothermic body temperatures. Little is known about the effects of perchlorate on metabolic capacity. The objectives of the present study were to determine if subchronic (51 d; 0, 1, and 10 mg/kg/d) and chronic (180 d; 0.75 mg/kg/d) perchlorate exposure in adult male prairie voles (Microtus ochrogaster) would alter resting metabolic rates as a result of decreased circulating thyroid hormone concentrations and to determine if perchlorate exposure disrupts thermogenesis in mammals exposed to cold stress. Voles exposed to perchlorate for 51 or 180 d experienced no significant alterations in resting metabolic rates at any point during the exposure period. Additionally, the treatment had no effect on peak metabolic rates or plasma thyroid hormone concentrations. However, thyroid gland T4 concentrations were significantly lower in perchlorate-exposed voles than in controls, indicating that thyroid gland T4 content may be a more sensitive endpoint than other thyroid variables for assessing perchlorate exposure. Overall, the present study did not provide evidence for energetic alterations associated with perchlorate exposure at concentrations that are higher than those typically found in groundwater or surface water in the environment.
Web search strategies and human individual differences: A combined analysis
Authors: Ford Nigel , Miller David , Moss Nicola 
Published: March 2005

AbstractThis is the second of two articles published in this issue of JASIST sreporting the results of a study investigating relationships between Web search strategies and a range of human individual differences. In this article we provide a combined analysis of the factor analyses previously presented separately in relation to each of three groups of human individual difference (study approaches, cognitive and demographic features, and perceptions of and approaches to Internet‐based information seeking). It also introduces two series of regression analyses conducted on data spanning all three individual difference groups. The results are discussed in terms of the extent to which they satisfy the original aim of this exploratory research, namely to identify any relationships between search strategy and individual difference variables for which there is a prima facie case for more focused systematic study. It is argued that a number of such relationships do exist. The results of the project are summarized and suggestions are made for further research.
SP100B is a repressor of gene expression
Authors: Wilcox Kent W. , Sheriff Scott , Isaac Anne , Taylor Jerry L. 
Published: March 2005

AbstractMammalian cell nuclei exhibit discrete sites where specific proteins characteristically localize. PML nuclear bodies (PML NBs) (nuclear domain 10s (ND10s)) are the primary localization site for the promyelocytic leukemia (PML) protein and the SP100 autoantigen. The observations that some PML and SP100 isoforms can function as transcriptional regulators, that both the size and number of PML bodies increase in response to interferon treatment, and that many mammalian viruses encode proteins that mediate disruption of PML bodies suggest that these sites suppress viral infection, perhaps by repressing viral gene expression. We hypothesized that a component of PML NBs functions as a repressor of gene expression. To test this hypothesis, we characterized the effect of PML or SP100 isoforms on expression of transfected reporter genes. PML‐I, PML‐VI, and SP100A did not repress reporter gene expression. In contrast, SP100B repressed reporter gene expression, especially under conditions in which the reporter gene expression was elevated by a viral transactivator or addition of trichostatin A to the culture medium. The SP100B DNA binding domain was required for repression. SP100B had no detectable effect on the amount, methylation pattern, or topological form of plasmid DNA in the nuclei of transfected cells. The demonstrated repressive activity of SP100B supports the hypothesis that SP100B is a component of an innate immune response that represses expression of ectopic DNA. © 2005 Wiley‐Liss, Inc.
Imprinting centers, chromatin structure, and disease
Authors: Soejima Hidenobu , Wagstaff Joseph 
Published: March 2005

AbstractTwo regions that best exemplify the role of genetic imprinting in human disease are the Prader–Willi syndrome/Angelman syndrome (PWS/AS) region in 15q11‐q13 and the Beckwith–Wiedemann syndrome (BWS) region in 11p15.5. In both regions, cis‐acting sequences known as imprinting centers (ICs) regulate parent‐specific gene expression bidirectionally over long distances. ICs for both regions are subject to parent‐specific epigenetic marking by covalent modification of DNA and histones. In this review, we summarize our current understanding of IC function and IC modification in these two regions. © 2005 Wiley‐Liss, Inc.
Improved artery delineation in dual‐stack coronary magnetic resonance angiography using parallel imaging at 3 T
Authors: Huber Michael E. , Kozerke Sebastian , Boesiger Peter 
Published: March 2005

AbstractPurposeTo improve vessel sharpness and T2 preparation (T2Prep) in dual‐stack three‐dimensional coronary magnetic resonance angiography (MRA) by shortening the time delays between the magnetization preparation pulses and the imaging stacks using sensitivity encoding (SENSE) at 3 T.Materials and MethodsBy combining dual‐stack three‐dimensional coronary MRA with the parallel imaging technique SENSE at 3 T, the acquisition duration of each three‐dimensional imaging stack was shortened by a factor of 2. The proposed technique was implemented and tested in experiments with a moving phantom and in measurements on six healthy volunteers.ResultsThe time delay between the navigator, T2Prep, and second imaging stack was reduced by 37%, relative to conventional dual‐stack angiography without parallel imaging. This enabled the achievement of comparable high‐vessel sharpness values for the left and the right coronary arteries relative to values known from conventional single‐stack three‐dimensional coronary MRA at 3 T.ConclusionParallel imaging allows for improved vessel visualization in dual‐stack coronary MRA, given shorter temporal delays between navigator, T2Prep, and the actual image acquisitions, and thus considerably facilitates simultaneous acquisition of high‐resolution angiograms of the left and right coronary systems. J. Magn. Reson. Imaging 2005;21:443–448. © 2005 Wiley‐Liss, Inc.
Peripheral axon caliber and conduction velocity are decreased after burn injury in mice
Authors: Higashimori Haruki , Whetzel Thomas P. , Mahmood Tamara , Carlsen Richard C. 
Published: March 2005

AbstractPeripheral neuropathies are reported to arise as a result of the systemic inflammatory response produced by a full‐thickness cutaneous burn injury. This study was designed to characterize the magnitude and time course of functional and morphological changes in peripheral axons that arise after a full‐thickness dermal burn injury in an animal model. A 20% body surface area (20% BSA) full‐thickness dermal burn was applied to the back of C57BL6 female mice. Longitudinal H‐ and M‐wave recordings were used to determine the conduction velocities (CV) of large myelinated motor and sensory axons in the tibial nerve of sham control and burn‐injured mice. Motor CVs were significantly reduced from 6 h to 28 days after the burn, and sensory CVs were significantly reduced from 7 to 14 days after the burn. Morphological evaluation also showed that the mean caliber of large axons in tibial nerves and L5 ventral and dorsal roots in burned mice was significantly decreased. The results demonstrate that both functional and morphological deficits may be produced in peripheral nerve axons at sites well removed from a full‐thickness dermal burn injury. The neural deficits may contribute to changes in neuromuscular transmission and the development of limb and respiratory muscle weakness that also accompany burn injury. Muscle Nerve, 2005