bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polycyclic aromatic hydrocarbon levels in mussels from prince william sound, ALASKA, USA, document the return to baseline conditions
Authors: Boehm Paul D , Page David S , Brown John S , Neff Jerry M , Burns William A 
Published: November 2004

Abstract
Bioavailable hydrocarbons in the Exxon Valdez oil spill zone in Prince William Sound (PWS; AK, USA) shorelines were at or near background levels in 2002, as indicated by low concentrations of polycyclic aromatic hydrocarbons (PAHs) in mussels (Mytilus trossulus) collected from sites throughout PWS. Total PAH (TPAH) minus parent naphthalene concentrations in mussels collected in 1998 to 2002 from sites oiled in 1989 were at or near reference-site values. Both oiled and reference sites included locations associated with past human and industrial activity (HA). Inclusion of the unoiled HA sites in the range of reference sites that define prespill conditions is consistent with federal regulations. For the period from 1998 to 2002, the geometric mean of TPAH concentrations for 218 mussel samples collected from 72 sites, including four HA sites that had been heavily oiled in 1989, is 54 ng/g dry weight (range, 2–1,190 ng/g). The maximum mussel TPAH concentrations are equivalent to a weathered-oil exposure dose to intertidal foragers that is one to three orders of magnitude less than the doses shown to cause sublethal effects in surrogate species. The geometric mean of TPAH concentrations for mussel samples from 28 locations not oiled in 1989 and unaffected by human use (NHA sites) is 28 ng/g (range, 3–355 ng/g), whereas the geometric mean of TPAH concentrations for mussel samples from 14 locations not oiled in 1989 and affected by human use (HA sites) is 106 ng/g (range, 2–12,056 ng/g). The range of data for the unoiled HA and NHA sites defines the background of bioavailable PAHs to mussels on western PWS shorelines that would have prevailed if the oil spill had not occurred. The low PAH concentrations in mussels from sites known to have subsurface oil residues demonstrates the low bioavailability of these spill remnants and, thus, are a low additional risk to foraging wildlife. The present study shows continuous exposure from four- to six-ring PAHs originating at HA sites in western PWS. At low concentrations, these PAHs are known to cause adverse biological effects. However, in the context of PWS, oiled and HA sites represent a small percentage (∼0.1–0.2%) of the total PWS shoreline.
Accumulation of tributyltin in Hyalella azteca as an indicator of chronic toxicity: Survival, growth, and reproduction
Authors: Bartlett Adrienne J , Borgmann Uwe , Dixon D. George , Batchelor Suzanne P , Maguire R. James 
Published: November 2004

Abstract
The chronic toxicity of tributyltin (TBT) was examined by exposing two successive generations of the freshwater amphipod, Hyalella azteca, to sediments spiked with TBT. Survival was the most sensitive measure of effect, with lethal concentration resulting in 50% mortality (LC50) values on a water and body concentration basis ranging from 76 to 145 ng Sn/L and 2,790 to 4,300 ng Sn/g, respectively. Individual growth of amphipods was not negatively affected by TBT, and although reproduction might be more sensitive than survival, the data were too variable to use on a routine basis. There were no detectable TBT-induced differences in the response between first- and second-generation animals. The relationship between toxicity and bioaccumulation of TBT in H. azteca was determined and can be used as a tool to predict the toxicity of TBT in environmental samples. Body concentrations exceeding 2,000 ng Sn/g in H. azteca exposed to field-collected samples would indicate that chronic toxicity due to TBT is likely occurring in amphipod populations at those sites.
A ranking system for the evaluation of intersex condition in european flounder (Platichthys flesus)
Authors: Bateman Kelly S , Stentiford Grant D , Feist Stephen W 
Published: November 2004

Abstract
Intersex (ovotestis) is the condition whereby an individual possesses oocytes, at varying degrees of severity, within the normal testicular tissue and is regarded as an endpoint of endocrine disruption in male fish. The occurrence of intersex has been linked with exposure to endocrine-disrupting compounds present in the environment, which are thought to mimic the actions of the female sex hormone 17-β-oestradiol. Using stained histological sections of archived cases of intersex from European flounder (Platichthys flesus), this study developed a grading method to assess the extent of the condition. This was termed the ovotestis severity index (OSI). The OSI utilizes the distribution pattern (focal, diffuse, cluster, zonal) and type of oocyte (previtellogenic, cortical alveolar, vitellogenic) to assign a severity rating to each intersex fish. A high OSI refers to fish with testicular material almost completely replaced with mature (vitellogenic) oocytes, and lower scores indicate those fish with small numbers of immature (previtellogenic) oocytes. The development of this index provides pathologists with a robust tool for the grading of the intersex condition in European flounder and potentially in other fish species.
Predicting the toxicity of chromium in sediments
Authors: Berry Walter J , Boothman Warren S , Serbst Jonathan R , Edwards Philip A 
Published: November 2004

Abstract
Chromium exists in sediments in two oxidation states: Cr(III), which is relatively insoluble and nontoxic, and Cr(VI), which is much more soluble and toxic. Chromium(VI) is thermodynamically unstable in anoxic sediments, and acid-volatile sulfide (AVS) is formed only in anoxic sediments; therefore sediments with measurable AVS concentrations should not contain toxic Cr(VI). If this hypothesis holds true, measuring AVS could form the basis for a theoretically based guideline for Cr in sediments. Ten-day water-only and spiked sediment toxicity tests with the amphipod Ampelisca abdita were performed with Cr(VI) and Cr(III), along with sediments collected from a site contaminated with high concentrations of Cr. In sediments where AVS exceeded analytical detection limits, Cr concentrations in interstitial water were very low (&lt;100 μg/L) and no significant toxicity to A. abdita was observed. In sediments in which AVS was not significantly greater than zero, Cr concentrations in interstitial waters increased significantly, with greater than 90% of the Cr present as Cr(VI), and mortality of A. abdita was elevated. These results demonstrate that measurements of AVS and interstitial water chromium can be useful in predicting the absence of acute effects from Cr contamination in sediments.
Enhancement of phenanthrene solubilization and biodegradation by trehalose lipid biosurfactants
Authors: Chang Jae-Soo , Radosevich Mark , Jin Yan , Cha Daniel K 
Published: November 2004

Abstract
Effects of trehalose lipid biosurfactants produced by Rhodococcus erythropolis on the solubilization and biodegradation of phenanthrene (PHE) were investigated. Based on surface tension measurements, the average critical micelle concentration (CMC) of trehalose lipids was determined to be approximately 16 mg total organic carbon (TOC)/L. In solubilization assays, the addition of biosurfactants at 20-fold the CMC increased the apparent solubility of PHE by more than 30-fold. Using a known PHE degrader (isolate P5-2), batch PHE biodegradation experiments were conducted, with and without trehalose lipids, in three systems: Water (devoid of soil solids), soil (Kenansville loamy sand having 0.72% organic matter), and soil-water slurry. Addition of trehalose lipids at 10-fold the CMC enhanced both the rate and the extent of PHE mineralization by isolate P5–2 in the liquid culture. The addition of biosurfactant (32.2 mg TOC/kg soil) to the soil system also increased both the initial rate (by more than twofold) and the extent of PHE mineralization. Biosurfactants increased the rate, but not the extent, of PHE mineralization in the soil-water slurry. The results obtained in the present study indicate that the trehalose lipid biosurfactants produced by R. erythropolis have good solubilization capacity for hydrophobic organic compounds and great potential for applications in bioremediation of sites contamination with polycyclic aromatic hydrocarbons.
Dietary mercury exposure and bioaccumulation in southern leopard frog (Rana sphenocephala) larvae
Authors: Unrine Jason M , Jagoe Charles H 
Published: November 2004

Abstract
Aufwuchs was collected from three reservoirs, a constructed wetland used for groundwater treatment, and mercury (Hg)-enriched mesocosms to examine the relationship between inorganic Hg and methylmercury concentrations in the diet of tadpoles. Four diets were then formulated with Hg-enriched aufwuchs to concentrations that bracketed those of Hg observed in aufwuchs from the field and reported in the literature from sites contaminated by atmospheric deposition. The diets were fed to southern leopard frog tadpoles in the laboratory for the entire larval period (60–254 d). Metamorphs and tadpoles were analyzed for inorganic Hg and methylmercury contents by gas chromatography—cold-vapor atomic fluorescence spectrophotometry. Methylmercury concentration increased with total Hg concentration in aufwuchs, but the proportion of methylmercury to inorganic Hg decreased with increasing total Hg concentration. In the feeding experiment, there was an inverse relationship between Hg exposure concentration and the bioaccumulation factor for each Hg species. We concluded that neither methylmercury nor inorganic Hg in aufwuchs is highly bioavailable to tadpoles and that bioaccumulation is not well explained by a simple partitioning model. This suggests that bioaccumulation factors as currently used are not the best predictors of dietary Hg bioaccumulation.
Identification of estrogenic compounds in wastewater effluent
Authors: Nakada Norihide , Nyunoya Hiroshi , Nakamura Masaru , Hara Akihiko , Iguchi Taisen , Takada Hideshige 
Published: November 2004

Abstract
In order to identify the dominant contributors to estrogenic activity in environmental waters, a comprehensive fractionation method using silica gel column chromatography, combined with recombinant yeast assay for detecting estrogenic activity and with gas chromatography–mass spectrometry for quantifying endocrine disruptors and natural estrogens, was developed. The method was applied to the municipal sewage treatment plant (STP) secondary effluent discharged to the Tamagawa River in Tokyo, Japan, where endocrine disruption was observed in wild carp. The instrumental analysis demonstrated that averaged concentrations of nonylphenol, bisphenol A, estrone (E1), and 17β-estradiol (E2) were 564 ± 127, 27 ± 19, 33 ± 11, and 4.6 ± 3.0 ng/L, respectively. Based on the concentration and relative potency of these compounds, the natural estrogens E1 and E2 represented more than 98% of the total estrogen equivalent concentration (EEQ) in the STP effluent, while the contribution of phenolic compounds to total EEQ was less than 2%. Estrogenic activities associated with the dissolved phase of the effluent samples were detected by a recombinant yeast assay. By using silica gel column chromatography, the dissolved phase was separated into several fractions that were subjected to the bioassay. The polar fractions exhibited estrogenic activity. The greatest estrogenic activity was found in a polar fraction containing E1 and E2 and represented 66 to 88% of the total estrogenic activities estimated from the bioassay data. These results lead to the conclusion that E1 and E2 were the dominant environmental estrogens in the STP effluent, but a significant contribution to estrogenic activities stems from unidentified components in the effluents.
Effect of ethoxylate number and alkyl chain length on the pathway and kinetics of linear alcohol ethoxylate biodegradation in activated sludge
Authors: Itrich Nina R , Federle Thomas W 
Published: November 2004

Abstract
Batch activated-sludge die-away studies were conducted with various pure homologs to determine the effect of ethoxylate number and alkyl chain length on the kinetics of primary and ultimate biodegradation of linear alcohol ethoxylates. The 14C-(ethoxylate) homologs C14E1, C14E3, C14E6, and C14E9 were used to investigate the effect of ethoxylate number, and 14C-(ethoxylate) homologs C12E6, C14E6, and C16E6 were used to examine the effect of chain length. Activated sludge was dosed with a trace concentration (0.2 μM) of each homolog, and the disappearance of parent, formation of metabolites, production of 14CO2, and uptake into solids were monitored with time. Ethoxylate number had little effect on the first-order decay rates for primary biodegradation, which ranged from 61 to 78 h−1. However, alkyl chain length had a larger effect, with the C16 chain-length homolog exhibiting a slower rate of parent decay (18 h−1) compared to its corresponding C12 and C14 homologs (61–69 h−1). Ethoxylate number affected the mechanism of biodegradation, with fission of the central ether bond to yield the corresponding fatty alcohol and (poly)ethylene glycol group increasing in dominance with increasing ethoxylate number. Based upon the measured rates of primary biodegradation, removal of parent during activated-sludge treatment was predicted to range between 99.7 and 99.8% for all homologs except C16E6, which had a predicted removal of 98.9%. Based upon the measured rates of ultimate biodegradation, removal of ethoxylate-containing metabolites was predicted to exceed 83% for all homologs. These predictions corresponded closely with previously published removal measurements in laboratory continuous activated-sludge systems and actual treatment plants.
Viscosity aging of poly(vinyl chloride) plastisol: The effect of the resin type and plasticizer type
Authors: Nakajima N. , Harrell E. R. 
Published: November 2004

AbstractThe viscosity of freshly prepared poly(vinyl chloride) (PVC) plastisol increases with time, and this phenomenon is called viscosity aging. The increase is rapid in the beginning and slows down to a quasistable value, but a very slow increase continues. The phenomenon may be a result of either the deagglomeration of agglomerated particles or the dissolution of low‐molecular‐weight PVC into the plasticizer. In this work, two typical commercial resins were used, one containing friable agglomerates and the other containing nonfriable agglomerates. With the friable‐agglomerate resin, about 40% of the initially present agglomerates deagglomerated, whereas the viscosity increased in a week to twice the initial value. With the nonfriable‐agglomerate resin, very fine and very low molecular weight particles, about 3% of all the particles, dissolved into the plasticizer in 2 days. The effect of the plasticizer type on the viscosity aging through deagglomeration was investigated with four plasticizers and three plasticizer blends. The emulsifiers used for polymerization, and retained through drying, affected the aging in the beginning. On the other hand, the viscosity after 1 week was free from the effect of the emulsifier and was affected only by the plasticizer type. With the exception of two blends, the 1‐week viscosity was quantitatively related to the dielectric constant divided by the molecular weight of the plasticizer. For the plasticizer blends, one of the plasticizers could have a dominant effect on the promotion of deagglomeration. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 448–464, 2005
Immobilization of a High‐Valent Rhenium Complex on an Indium‐Doped Tin‐Oxide Electrode: Enhanced Catalytic Activity of a trans‐Dioxorhenium(V) Complex in Electrochemical Oxidation of Alcohols
Authors: Sugimoto Hideki , Tsukube Hiroshi , Tanaka Koji 
Published: November 2004

AbstractA high‐valent trans‐dioxorhenium(V) complex containing pyridine ligands was successfully immobilized on an ITO (indium‐doped tin‐oxide) electrode. The complex formed a monolayer structure on the electrode surface and promoted electrochemical catalytic oxidation of 1‐phenylethanol to acetophenone in CH2Cl2. Oxidation hardly occurred in CH2Cl2 solution containing the free rhenium(V) complex. Immobilization of other high‐valent metal complexes will present opportunities for design of functional electrodes with high activities. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Spatial and Temporal Variations of Detritus Breakdown Rates in the River Flumendosa Basin (Sardinia, Italy)
Authors: Fonnesu Alessio , Pinna Maurizio , Basset Alberto 
Published: November 2004

AbstractHere we analyse in a 5th order Mediterranean river (River Flumendosa, Sardinia, Italy) spatial and temporal variations of plant detritus processing, a key functional aspect of river ecosystems. Decay rates of dead leaves (Phragmites australis) were studied during the fall‐winter and spring‐summer seasons at 17 sites distributed among 5 stream orders. Litter decay rates varied more, and were higher in spring‐summer than in fall‐winter. On the spatial scale, patterns of decay rate variation among sites and orders did not vary between seasons; seasonal variation was low in reaches with slow rates and high in reaches with fast rates. Data analysis showed a spatial pattern of increasing reed detritus decay rates with increasing stream order. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Intergenerational relationships and partnerships in community programs: Purpose, practice, and directions for research
Authors: Zeldin Shepherd , Larson Reed , Camino Linda , O'Connor Cailin 
Published: November 2004

AbstractThis article serves as an introduction to the special issue and to the emerging topic of intergenerational relationships and partnerships in community programs. Our aim is to offer a frame in which to consider theory and practice on the topic. Toward that end, we focus on the multiple purposes of intergenerational relationships, adult strategies for creating strong relationships, and the organizational supports necessary to support relationships and partnerships. This analysis highlights program examples from the 10 articles included in this volume. We conclude by identifying key issues that researchers may explore to further enhance our understainging of youth–adult relationships and partnerships. © 2005 Wiley Periodicals, Inc. J Comm Psychol 33: 1–10, 2005.
Pitfalls and promising practices of youth–adult partnerships: An evaluator's reflections
Authors: Camino Linda 
Published: November 2004

AbstractYouth–adult partnerships (Y‐APs) are an innovation being used increasingly as a key strategy for promoting youth development, as well as for building strong programs and communities. This article discusses three pitfalls that can undermine their effectiveness: (1) the assumption that youth should do everything of importance; (2) the belief that adults should “get out of the way,” and give up power, and (3) the focus on youth as the marked category. The article also describes three promising practices to overcome pitfalls: (1) integrate reflection into meetings; (2) articulate the logic of programs and Y‐APs; and (3) engage a third party to help explore group assumptions and values. © 2005 Wiley Periodicals, Inc. J Comm Psychol 33: 75–85, 2005.
Shell growth and chamber formation of aquarium‐rearedNautilus pompilius(Mollusca, Cephalopoda) by X‐ray analysis
Authors: Westermann Bettina , Beck‐Schildwächter Ingrid , Beuerlein Knut , Kaleta Erhard F. , Schipp Rudolf 
Published: November 2004

AbstractObservations on the growth rate of aquarium maintainedNautilus pompiliusin different developmental stages, i.e. juveniles (shell length about 8.75 cm), late juveniles (≈10 cm), and early adolescent (≈13.5 cm), indicate that this species is fully grown at an age of 7.3–8 years. The age calculations are based on two different computations: (1) the measurement of the increase of the shell length per day and (2) the formation of new septa in time intervals of 150±5 days, as demonstrated by X‐ray analyses. AfterN. pompiliushatches, its shell grows about 139 mm to reach full growth and approximately 28 septa are formed. With an increase of the shell length of 0.052 mm per day, it takes about 2,673 days (7.3 years) to reach maturity. Provided that the process of chamber formation follows an exponential function, these computations result in ≈2,925 days (8 years) to reach full maturity. Supposing thatN. pompiliusmay live for several years after onset of maturity likeNautilus belauensis, the total life span for this species may exceed 11–12 years.J. Exp. Zool. 301A:930–937, 2004.© 2004 Wiley‐Liss, Inc.
Partial‐volume effect on ischemic tissue‐fate delineation using quantitative perfusion and diffusion imaging on a rat stroke model
Authors: Ren Hongxia , Shen Qiang , Bardutzky Juergen , Fisher Marc , Duong Timothy Q. 
Published: November 2004

AbstractPartial‐volume effects (PVE) in stroke imaging could hinder proper delineation of normal, ischemic, and at‐risk tissues. Cerebral‐blood‐flow (CBF) and apparent diffusion coefficient (ADC) were measured at high and low resolution (HR = 128 × 128, LR = 64 × 64) in focal ischemia in rats during the acute phase. The data were evaluated for PVE on ischemic tissue classification on a pixel‐by‐pixel basis and the misclassified pixels were quantified as ischemia progressed. The main drawbacks of high‐resolution imaging are reduced temporal resolution and/or signal‐to‐noise ratio. The high‐ versus low‐resolution scatterplots and histograms of pixels along the normal–abnormal boundaries in the ADC and CBF maps showed marked ischemia‐related PVE. By comparison with the homologous regions in the contralateral normal hemisphere, the effect of increased noise and intrinsic tissue heterogeneity due to high resolution could be distinguished from ischemia‐related PVE. Degrading the high‐resolution (128 × 128) data to a 64 × 64 or 32 × 32 matrix increased the severity of PVE. Zero‐filling of low‐resolution (64 × 64) data to 128 × 128 also increased PVE. It was concluded that PVE: (1) misclassified substantial pixels along the normal–abnormal boundaries, (2) overestimated abnormal volumes at the expense of mostly “at‐risk” and some “normal” tissues, (3) were more severe at the early time points postischemia, and (4) confounded the interpretation of the operationally defined ischemic penumbra. Magn Reson Med 52:1328–1335, 2004. © 2004 Wiley‐Liss, Inc.
The dominance of Kenyans in distance running
Authors: Pitsiladis Yannis P , Onywera Vincent O , Geogiades Evelina , O'Connell William , Boit Michael K 
Published: November 2004

AbstractKenyan runners, and especially those originating from the Kalenjin tribe, have dominated international middle- and long-distance running for over 40 years, prompting significant interest in the factors contributing to their success. Proposed explanations have included environmental factors, psychological advantage and favourable physiological characteristics, which may be genetically conferred or environmentally determined. Running is inherent within local Kenyan tradition and culture, and the Kenyan way of life, which involves many outdoor activities and pastimes in addition to mostly unfavourable living conditions, is conducive to enhanced distance running performance. Despite economic deprivation, Kenya has produced world and international running champions repeatedly over the past few decades; these champions have become role models for the younger generations, who take up running in the hope of a better future for themselves. Favourable environmental conditions such as altitude, diet and anthropometry, in addition to the motivational and socio-economic factors mentioned above, have all been proposed as possible reasons for the unsurpassed achievements of Kenyan distance runners. However, the fact that the majority of internationally successful runners originate from a small tribe that accounts for approximately 3% of the total Kenyan population also points to a possible genetic component. Whether this is subject to influence from other co-factors, such as altitude or training effects acquired during childhood, remains as yet unresolved.