bluuebunny/crossref_metadata_2025 huggingface dataset:
Bioaccumulation of metals in plants, arthropods, and mice at a seasonal wetland
Authors: Torres Kevin C , Johnson Michael L
Published: March 2010

Concentrations of arsenic, cadmium, copper, lead, and nickel were measured in soils, house mice (Mus musculus), and the main food items of this omnivorous mouse to examine the occurrence of these metals in selected components of a seasonal wetland. Soil concentrations of copper, lead, and (in some areas) nickel were elevated, but extractable soil concentrations indicated low bioavailability of metals. Levels of most metals in mice and composited arthropods were consistent with reference site concentrations from other studies. However, copper was found to be particularly mobile within the local ecosystem and accumulated in house mouse carcasses and composited arthropods at substantial levels. Metal residues in Scirpus robustus (alkali bulrush) roots exceeded those in seeds, consistent with patterns of bioaccumulation commonly observed in plants. Uptake and bioaccumulation factors for S. robustus seeds and roots, arthropods, and mouse carcasses and livers are reported. Concentrations of lead and nickel in S. robustus roots exhibited significant linear relationships with levels in soils. Copper levels in S. robustus seeds varied significantly with those in house mouse livers, suggesting that trophic transfer of copper from this food source to mice occurred. However, other spatial patterns of bioaccumulation in S. robustus and house mice relative to soil/seed concentrations were absent. Metal levels in house mice bore no relation to body weight or estimated age.
Biodegradation of bisphenol a in aquatic environments: River die-away
Authors: Kleĉka Gary M , Gonsior Stanley J , West Robert J , Goodwin Patrick A , Markham Dan A
Published: March 2010

The biodegradability of bisphenol A (BPA) was assessed in surface waters from seven different rivers across the United States and Europe. Rapid biodegradation of BPA was observed in all rivers following lag phases ranging from 2 to 4 d. Biodegradation half-lives for BPA were typically less than 2 d following the lag phase. Mineralization of BPA was observed in all river waters, with average carbon dioxide yields of approximately 76% of the theoretical maximum (range 59–103%) at the end of the incubation period (≤18 d). Short half-lives (0.5 to 3 d) were noted for BPA biodegradation in river waters regardless of geographic location, sampling site (i.e., upstream vs downstream of wastewater outfalls), sediment addition (≤0.05%), and initial test chemical concentration (50–5,500 μg/L). Subsequent studies conducted at environmentally relevant concentrations (0.05 and 0.5 μg/L) also indicated short half-lives (3–6 d) for BPA and support the extrapolation of the half-lives measured in this study over a wide range of environmental concentrations. The fact that BPA was degraded rapidly in surface waters taken from diverse locations in the United States and Europe as well as in studies recently conducted in Japan suggests that BPA degrading microorganisms are widely distributed in nature. These observations provide clear evidence that BPA is not persistent in the aquatic environment.
Accumulation of DDT and mercury in prothonotary warblers (Protonotaria citrea) foraging in a heterogeneously contaminated environment
Authors: Reynolds Kevin D , Rainwater Thomas R , Scollon Edward J , Sathe Smita S , Adair Blakely M , Dixon Kenneth R , Cobb George P , McMurry Scott T
Published: March 2010

Foraging areas of adult prothonotary warblers (Protonotaria citrea) were determined using standard radiotelemetry techniques to determine if soil concentrations of p,p′dichlorodiphenyltrichloroethane (p,p′DDT) and mercury in foraging areas could be used to predict contaminant levels in diets and tissues of nestling warblers. Adult warblers were fitted with transmitters and monitored for approximately 2 d while foraging and feeding 6- to 8-d-old nestlings. Foraging ecology data were integrated with contaminant levels of soil, diets, and tissues into a comprehensive analysis of geographic variation in contaminant exposure and uptake using linear regression. Concentrations of 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE) and mercury in nestling tissues varied considerably across the study site. Mean concentration of DDE was greater in eggs than all other tissues, with individual samples ranging from 0.24 to 8.12 μg/kg. In general, concentrations of DDT in soil were effective in describing the variation of contaminants in adipose samples. Concentrations of mercury in soils accounted for 78% of the variation in kidney samples. This was the best relationship of any of the paired variables. All other relationships showed relatively poor predictive ability.
Preferential biomagnification of aryl hydrocarbon hydroxylase- inducing polychlorinated biphenyl congeners in the Lake Michigan, USA, lower food web
Authors: Trowbridge Annette G. , Swackhamer Deborah L.
Published: March 2010

Preferential biomagnification of 14 dioxin-like polychlorinated biphenyls (PCBs) was determined in lower-trophic-level organisms of the Lake Michigan, USA, food web. Bioaccumulation of these coplanar, aryl hydrocarbon hydroxylase (AHH)- inducing PCB congeners and total PCBs in phytoplankton, zooplankton, Mysis relicta, and Diporeia sp. were studied for two locations in Lake Michigan over time. The results indicate that both total PCB and AHH-inducing PCBs biomagnify with increasing food web trophic level, with biomagnification of the AHH-inducing PCBs occurring to a greater degree. The biomagnification factors (BMFs) of the AHH-inducing PCBs suggest that they are highly conserved relative to other PCB congeners. The concentrations expressed as dioxin toxic equivalencies (TEQ concentrations) indicate that the biomagnification of AHH PCBs causes greater concentrations, and thus greater toxicity risk, with increasing trophic level.
Reduction in the estrogenic activity of a treated sewage effluent discharge to an english river as a result of a decrease in the concentration of industrially derived surfactants
Authors: Sheahan David A. , Brighty Geoff C. , Daniel Mic , Jobling Susan , Harries Jule E. , Hurst Mark R. , Kennedy Joe , Kirby Sonia J. , Morris Steven , Routledge Edwin J. , Sumpter John P. , Waldock Michael J.
Published: March 2010

As a result of the introduction of tighter discharge limits and effluent treatment processes at source, the concentration of alkylphenol ethoxylates and nonylphenol present in the final effluent discharge from a sewage treatment works that treats trade effluent from the textiles industry was reduced. The estrogenic effects of the final effluent discharge to the Aire River were compared over a four-year period during which various treatment measures were introduced. Male rainbow trout exposed to the effluent on four occasions in consecutive years (1994–1997) showed a reduction in the level of induced vitellogenesis between 1994 and 1997. A marked decrease in gonadosomatic index (GSI) and increase in heptaosomatic index (HSI) was measured in fish exposed to the effluent in 1994. In successive years, these differences diminished, and in the case of the GSI no measurable difference was observed between fish exposed to the final effluent or those in the control group in 1997. However, an increase in HSI was still measurable in 1997 in fish exposed to the final effluent and at sites farther downstream. The reduction in the effects of the effluent paralleled the reduction in the concentration of nonylphenol as well as its mono- and diethoxylates, which have been demonstrated to produce estrogenic effects in trout exposed to these compounds in the laboratory. This study demonstrates that the setting of more restricted discharge limits for known estrogenic chemicals of industrial origin can lead to significant reductions in the estrogenic activity of the watercourses into which the effluents are discharged.
Effects of larval exposure to triphenyltin on the survival, growth, and behavior of larval and juvenileAmbystoma barbourisalamanders
Authors: Rehage Jennifer Schöpf , Lynn Scott G. , Hammond John I. , Palmer Brent D. , Sih Andrew
Published: March 2010

We exposed 10 sibships of the streamside salamander, Ambystoma barbouri, to two concentrations of triphenyltin (TPT) (1 and 5 μg/L) and an acetone carrier control for the entirety of the larval period. We measured effects on larval feeding rates, escape behavior, growth rates, and survival to, days to, and size at metamorphosis. Postmetamorphosis, we monitored feeding rates, growth rates, and survival of juvenile A. barbouri in order to investigate carryover effects. The 5-μg/L TPT concentration resulted in 93% mortality of the larvae. Exposure to 1 μg/L TPT had no mortality effect and no effect on the escape behavior of larvae. However, larvae exposed to this TPT concentration had significantly lower feeding rates and growth rates and therefore metamorphosed later than the controls but at the same mass. We detected a direct effect of TPT on growth rates beyond the effect through depressed feeding rates. We also found significant evidence for variation among sibships in their sensitivity to TPT toxicity. Once exposure was terminated at metamorphosis, we observed no residual effects of TPT on juveniles. Survival, feeding, and growth rates of juveniles exposed to TPT as larvae were not significantly different from those exposed only to the acetone carrier.
Comparison of deterministic and probabilistic calculation of ecological soil screening levels
Authors: Regan Helen M. , Sample Brad E. , Ferson Scott
Published: March 2010

The U.S. Environmental Protection Agency (U.S. EPA) is sponsoring development of ecological soil screening levels (Eco-SSLs) for terrestrial wildlife. These are intended to be used to identify chemicals of potential ecological concern at Superfund sites. Ecological soil screening levels represent concentrations of contaminants in soils that are believed to be protective of ecological receptors. An exposure model, based on soil- and food-ingestion rates and the relationship between the concentrations of contaminants in soil and food, has been developed for estimation of wildlife Eco-SSLs. It is important to understand how conservative and protective these values are, how parameterization of the model influences the resulting Eco-SSL, and how the treatment of uncertainty impacts results. The Eco-SSLs were calculated for meadow voles (Microtus pennsylvanicus) and northern short-tailed shrews (Blarina brevicauda) for lead and DDT using deterministic and probabilistic methods. Conclusions obtained include that use of central-tendency point estimates may result in hazard quotients much larger than one; that a Monte Carlo approach also leads to hazard quotients that can be substantially larger than one; that, if no hazard quotients larger than one are allowed, any probabilistic approach is identical to a worst-case approach; and that an improvement in the quality and amount of data is necessary to increase confidence that Eco-SSLs are protective at their intended levels of conservatism.
Low metal bioavailability in a contaminated urban site
Authors: Ge Ying , Murray Patricia , Sauvé Sébastien , Hendershot William
Published: March 2010

Bioavailability of Cd, Cu, Ni, Pb, and Zn in a metal-enriched railway yard in Montréal, Québec, Canada was assessed using metal speciation, plant uptake, and microbial assays. Metal speciation of extracted soil solutions was estimated using the Windmere Humic Aqueous Model. In soil solutions, free Cd, Ni, and Zn ions represented as much as 80%, 72%, and 62%, respectively, of the total dissolved metals. Copper and Pb were strongly bound by dissolved organic matter, and metal—fulvic acid complexes represented as much as 99% of the total dissolved metals. Three field-collected plant species (dandelion, bladder campion, and chicory) varied in their tendency to accumulate metals in either their leaves or roots. Chicory grown in the greenhouse had significantly higher metal bioconcentration factors than wild chicory. Although the site studied is considered to be contaminated, no metal pool, such as free ions or dissolved or total soil metals, consistently predicted metal uptake by potted chicory. Regression analysis revealed that soil total metal concentrations could adequately predict tissue accumulations of Cd, Ni, Pb, and Zn in bladder campion but only Cd and Zn in dandelion. Data from microbial assays also showed that the soil respiration was not affected by the metal contamination, but that nitrification was inhibited for the most contaminated soils. These results indicate that the metal bioavailability in the railway yard is low, but they also suggest that nitrogen cycling may be affected.
Simultaneous measurement of uptake and elimination of cadmium by caddisfly (Trichoptera: Hydropsychidae) larvae using stable isotope tracers
Authors: Evans R. Douglas , Balch Gordon C. , Evans Hayla E. , Welbourn Pamela M.
Published: March 2010

The use of stable isotopes coupled with inductively coupled plasma—mass spectrometry provides a unique opportunity to investigate pathways of metals in aquatic invertebrates. In this study, the simultaneous uptake and elimination of cadmium (Cd) in stream-dwelling caddisfly (Trichoptera: Hydropsychidae) larvae was measured in laboratory experiments with stable isotopes of Cd. In one experiment, animals were exposed to low levels (0.5 μg/L) of 114Cd in filtered river water and uptake was measured for 9 d, followed by 9 d during which the larvae were exposed to either 114Cd, 113Cd, or filtered river water. In a second experiment, the initial exposure concentration of 114Cd varied from 0.1 to 1.6 μg/L for 5 d, followed by 5 d during which the larvae were exposed to the same respective levels of 113Cd. The purpose of the two experiments was to test whether or not elimination of 114Cd from Hydropsyche larvae was the same in the presence or absence of Cd in the water and also whether or not elimination rates were dependent on exposure concentration. The results indicated that elimination of Cd by Hydropsyche larvae (elimination rate constant ∼ 0.21–0.24/d) in the presence of Cd in the water was the same as the depuration when no metal was present. Furthermore, the elimination rate was independent of exposure concentrations, ranging between 0.1 and 1.6 μg/L. Thus, the stable isotope tracer technique enabled the simultaneous measurement of uptake and elimination of Cd in hydropsychid larvae and may have the potential to facilitate the labeling of various compartments (e.g., water, sediment, and food) in the aquatic environment.
Acute toxicity of triorganotin compounds: Different specific effects on the energy metabolism and role of pH
Authors: Hunziker René W. , Escher Beate I. , Schwarzenbach René P.
Published: March 2010

Triorganotin compounds exhibit several modes of toxic action on the energy metabolism in energy-transducing membranes. The inhibition of the adenosine triphosphate (ATP) synthase and the hydroxide/chloride-antiport have been extensively investigated, but debate still exists on whether further mechanisms are relevant. In this work, two possible further effects have been investigated: inhibition of the bc1 complex and the hydroxide uniport, and in addition, the overall inhibition of the ATP synthesis was investigated in chromatophores of the photosynthetic purple bacterium Rhodobacter sphaeroides at pH = 7.5 and pH = 6.1. Experimental conditions were chosen in order to exclude the hydroxide/anion antiport as a possible effect. Inhibition of the cytochromes bc1 complex was detected, but at such high concentrations that it is not relevant for acute toxicity. Tributyltin was found to induce a decrease of the membrane potential, which can be attributed to a hydroxide uniport, whereas for triphenyltin no such activity was observed. For both compounds, inhibition of the ATP synthesis was higher at pH = 6.1 than at pH = 7.5. Also the hydroxide uniport activity of tributyltin was higher at lower pH. The contribution of the hydroxide uniport of tributyltin to the overall inhibition of the ATP synthesis cannot be quantified; however, hydroxide uniport occurred in the same concentration range as inhibition of the ATP synthesis. For triphenyltin, inhibition of the ATP synthesis can be attributed to the inhibition of the ATP synthase. It was concluded that chromatophores of R. sphaeroides are a useful system to discriminate various effects of toxicants on the energy metabolism of a cell.
Polychlorinated biphenyl source attribution in Green Bay, Wisconsin, USA, using multivariate similarity among congener profiles in sediment samples
Authors: Cacela Dave , Beltman Douglas J. , Lipton Joshua
Published: March 2010

Polychlorinated biphenyl (PCB) congener concentrations measured in 1,189 sediment samples from Green Bay (MI/WI, USA), Lake Michigan (MI/WI, USA), and the Fox River (WI, USA) were analyzed statistically to evaluate whether PCB congener profiles in outer Green Bay are more similar to those observed in inner Green Bay or Lake Michigan. Similarities among PCB profiles were assessed with complementary multivariate analysis techniques: Principal component analysis (PCA), cluster analysis, and classification trees. The PCA indicated that profiles in outer Green Bay are distinct from those of inner Green Bay or Lake Michigan but are more similar to those of inner Green Bay. The outer bay profiles are dissimilar to profiles that would result from a simple process of mixing contaminated sediments from the inner bay with Lake Michigan sediments and, therefore, support the conclusion that contaminants in outer Green Bay come from discharges of the Fox River. Several classification trees based on small sets of congener proportions defined simple rules that consistently distinguished the regional profiles. Application of these rules to classify the outer bay samples suggests that the profiles of less than 7% of outer bay samples are similar to Lake Michigan profiles. These results are interpreted with respect to physical transport and chemical weathering processes that may account for the observed differences.
Inherent and growth stage-related differences in growth and lipid and sterol composition of algal species sensitive and tolerant to sterol-inhibiting fungicides
Authors: Tuckey Donna M. , Orcutt David. M. , Hipkins P. L Loyd
Published: March 2010

Fourteen algal species representing five algal classes were evaluated as to the effects of four sterol-inhibiting fungicides (SIFs) on growth. Sensitivity to SIFs was related to species, chemical, and concentration. Species of Chlorella sensitive and tolerant to SIFs were further compared relative to inherent and growth stage-related differences in lipid, free sterol (FS), and steryl ester (SE) composition. Inherent and growth stage-related qualitative and quantitative differences in FS and SE composition were apparent between the two species examined. The qualitative FS and SE composition was particularly different. The importance of lipids, FS, and SE in membrane structure and control of membrane function is well established. Species differences and environmentally (growth stage, light, temperature, and nutrition) induced changes in lipid composition may be part of the basis for sensitive and tolerant responses to SIFs and xenobiotics in general. The ability of lipophilic xenobiotics to partition into membranes most likely depends on the qualitative and quantitative composition of membrane components, at any given time, and seems to be highly dynamic. Although the biochemical mechanism of action of SIFs is well established, the ability for passive bioaccumulation of such compounds in algae may be equally as important.
Response of macroinvertebrates to copper and zinc in a stream mesocosm
Authors: Hickey Christopher W , Golding Lisa A.
Published: March 2010

Metal pollution of streams and rivers is recognized as one of the major concerns for management of freshwaters. Macroinvertebrate communities were established within 12 artificial streams and exposed to three replicated concentrations of a metals mixture (copper and zinc) for 34 d. The cumulative criterion units (CCU = σ[metals]/hardness-adjusted U.S. Environmental Protection Agency [U.S. EPA] 1996 chronic criterion value) of total metals in the low, medium, and high treatments were 2.4, 5.9, and 18 CCUs. Zinc comprised approximately 75% of the CCUs in each of the treatments. Effects on taxa richness and the number of taxa in the orders Ephemeroptera, Plecoptera, and Trichoptera (EPT) were moderate at the high exposure concentration (−23% and −26% respectively, p < 0.05). All of the five major mayfly species showed near extinction, whereas four of the seven caddisflies showed stimulation (up to +121%) and three were reduced (up to −76%). Redundancy analysis for this metal gradient indicated that 94% of the variance in community structure was explained by three quantitative variables: total mayfly abundance, a mollusk (Potamopyrgus antipodarum) abundance, and the number of EPT individuals, indicating that multiple indices do provide improved predictors of metal stress. Most species showed a threshold response relationship, whereas some community indicators showed apparent hormetic responses (e.g., number of mayfly taxa, total taxa, and number of EPT taxa). Model concentration-response relationships with generalized linear models were used to provide threshold of 20% effective concentration values for species and community metrics. Threshold effect values ranged upwards of 1.4 CCUs, indicating that U.S.EPA chronic criteria would be protective of species and community responses.
Ten-week exposure to treated sewage discharge has relatively minor, variable effects on reproductive behavior and sperm production in goldfish
Authors: Schoenfuss Heiko L. , Levitt James T. , Van Der Kraak Glen , Sorensen Peter W.
Published: March 2010

It is well established that effluent from many sewage treatment plants (STPs) possesses estrogenic properties; however, the biological significance of this estrogenicity to fish reproductive behavior and sperm production is unknown. This study tested the hypothesis that 10-week exposure to a STP effluent with well-established estrogenic properties compromises the reproductive vigor of mature goldfish by decreasing the intensity of their reproductive drive and sperm production. Male goldfish were exposed for 10 weeks to one of four treatments: well water, a solvent control, 50 ng/L estradiol (E2), or undiluted effluent from a major metropolitan STP. Two trials were conducted, one in the winter and one in the summer when the effluent was chlorinated. Exposure to effluent in both the summer and winter trials induced small, but nonsignificant, decreases in the frequency of male spawning behaviors but had no effect on sperm production. Exposure to E2 caused a clear reduction in spawning behavior in one trial while causing reduced sperm production in both trials. We conclude that the effect of effluent exposure from this STP on adult fish is likely to be relatively minor and that the effluent's estrogenic properties may vary over the course of the year.
Atrazine and metribuzin sorption in soils of the argentinean humid pampas
Authors: Daniel Peter E. , Bedmar Francisco , Costa José L. , Aparicio Virginia C.
Published: March 2010

Laboratory studies were conducted to determine the influence of surface and subsurface properties of three representative soils of the humid pampas of Argentina on atrazine and metribuzin sorption. Atrazine and metribuzin sorption isotherms were constructed for each soil at four depths. Sorption affinity of herbicides was approximated by the Freundlich constant (Kf), distribution coefficient (Kd), and the normalized Kd based on organic carbon content (Koc). Multiple regression of the sorption constants against selected soil properties indicated that organic carbon content (OC) and silt were related positively and negatively, respectively, to atrazine Kf coefficient (r2 = 0.93), while Kd coefficient of atrazine was related positively to organic carbon content and negatively to both silt and cation exchange capacity (CEC) (r2 = 0.96). For metribuzin, only organic matter content was related positively to Kf coefficient (r2 = 0.51). Lower Kf values for atrazine were obtained for all soils with increasing depth, indicating lesser sorption at greater depths. Metribuzin sorption was quite similar across all depths. Sorption constant Kf of atrazine ranged from 2.06 to 7.82, while metribuzin Kf values ranged from 1.8 to 3.52 and were lower than atrazine for all soils and depths, indicating a greater leaching potential across the soil profile.
Trimethylpentane-containing passive samplers for predicting time-integrated concentrations of pesticides in water: Laboratory and field studies
Authors: Leonard Alex W. , Hyne Ross V. , Pablo Fleur
Published: March 2010

A laboratory continuous-flow system delivering known aqueous concentrations of pesticides to passive samplers was used to examine the kinetics of pesticide uptake and release. The passive samplers were constructed of low-density polyethylene membrane bags containing 2,2,4-trimethylpentane solvent (TRIMPS). Both uptake and release experiments were run in triplicate. Each experiment involved four treatments, including a control and three fivefold dilutions of a pesticide mixture that included the usual range of these pesticides as measured in the riverine environment of cotton-growing regions of Australia. The results indicated that for nonpolar pesticides with a log Kow > 3.5, uptake was linear over the 42-d exposure time and was independent of the treatment concentration. The half-lives for release of these pesticides from the TRIMPS varied from 26 to 130 d in clean water. The relatively polar pesticides with a log Kow < 3.5 had lower uptake rates into the TRIMPS because of their affinity for water. Release of trimethylpentane from the TRIMPS placed in 0.85-mm mesh nylon bags in river water was used as an indicator for chemical diffusion across the aqueous boundary to examine the effect of environmental factors. Most variability in solvent release in the field-deployed TRIMPS across all sites was explained by time of deployment and was not significantly influenced by river flow or water temperature. This suggests that river flow and water temperature may not be important in influencing uptake rates of pesticides into TRIMPS when employed in the field.
Toxicity of 19 adjuvants to juvenile Lepomis macrochirus (bluegill sunfish)
Authors: Haller William T. , Stocker Randall K.
Published: March 2010

Nineteen adjuvants, many used as surfactants for aquatic herbicide applications, were applied in static bioassay to bluegill sunfish (Lepomis macrochirus) for 96 h to determine median lethal concentrations (LC50). Surfactants are added to the tank mix as a percentage (v/v) of the total volume, in contrast to herbicide application rates, which are usually expressed in kilograms per hectare. Two ethoxylated tallow amine products were the most toxic, having LC50 values of 1.6 and 2.9 ppm (all values v/v). Seven alcohol/glycol-based surfactants had 96-h LC50 values of 4.0 to 11.6 ppm (mean = 7.9 ppm). The polysiloxane- or silicone-based surfactants had toxicities of 18.1 to 29.7 ppm (mean = 24.7). Two limonene-based products had LC50 values of 10.2 and 30.2 ppm. A methylated seed oil with emulsifier had a LC50 of 53.1 ppm. Two acid/buffer utility adjuvants had LC50 values of 60.8 and 221 ppm. To compare the relative safety of the tested surfactants, we assumed maximum label rate applications to 1 m deep water with uniform mixing. This comparison of relative safety is based on mortality to 50% of the test organisms and does not imply application rates that would not result in any mortality. The two ethoxylated tallow amines, neither used or recommended for aquatic applications, had a relative safety factor of 12.6 or less. Relative safety factor varied from 6.2 to 20.4 for the seven alcohol/glycol surfactants, 38.4 to 63.2 for silicone-based products, 5.5 to 16.1 for limonene products, 113 for methylated seed oil, and 132.2 to 315.7 for acid/buffer utility adjuvants. When used according to label recommendations under normal use conditions, these adjuvants should not be present in acutely toxic concentrations; however, the most toxic adjuvants in very shallow water (<10 cm) would be toxic to bluegill sunfish that did not move to deeper water to avoid lethal concentrations.
Short-term exposure to 17α-ethynylestradiol decreases the fertility of sexually maturing male rainbow trout (Oncorhynchus mykiss)
Authors: Schultz Irvin R. , Skillman Ann , Nicolas Jean-Marc , Cyr Daniel G. , Nagler James J.
Published: March 2010

The synthetic estrogen 17α-ethynylestradiol (EE2) is a commonly used oral contraceptive that has been increasingly detected in sewage effluents. This study determined whether EE2 exposure adversely affected reproduction in sexually maturing male rainbow trout (Oncorhynchus mykiss). We exposed male trout to graded water concentrations of EE2 (10, 100, and 1,000 ng/L) for 62 d leading up to the time of spawning. Semen and blood plasma samples were removed from each fish. Semen was used to fertilize groups of eggs from one nonexposed female. As a measure of fertility, eggs were incubated for 28 d after fertilization to determine the proportion that attained the eyed stage of embryonic development. Additional endpoints also measured included sperm motility, spermatocrit, gonadosomatic and hepatosomatic indices, testis histology, and circulating plasma levels of the sex steroids 17α, 20β-dihydroxyprogesterone (17,20-DHP) and 11-ketotestosterone (11-KT). Exposure to 1,000 ng/L of EE2 caused complete mortality of the treatment group by day 57. Exposure to lower EE2 water concentrations (10 and 100 ng/L) caused an increase in sperm density, while a significant reduction in testis mass was observed only in the 100-ng/L exposure group. Most significantly, semen harvested from fish exposed to 10 and 100 ng/L EE2 caused an approximately 50% reduction in the number of eggs attaining the eyed stage of embryonic development. Plasma levels of 17,20-DHP in exposed fish were roughly twice the level of the controls, while levels of 11-KT were significantly reduced in fish exposed to 100 ng/L EE2. These results suggest that sexually maturing male rainbow trout are susceptible to detrimental reproductive effects of short-term exposures to environmentally relevant levels of EE2.
Raumordnung, Landes- und Regionalplanung
Authors: Ritter Ernst-Hasso , Scholich Dietmar
Published: March 2010

Questions of comprehensive spatial planning at the various levels at which it is undertaken — in contrast to research questions, which tend largely to be concept-based — show a particularly strong orientation to the players active at the various levels of planning. The fields of action within spatial planning and their spatial impacts quite naturally pervade all fields of research. Consequently, these questions clearly have to be seen as displaying an overarching character. The special quality of this relationship is found in the evaluative reflection of spatial research which is carried out through the action fields of spatial planning practice. This article provides an application-based insight into the activities of the ARL workshop on this field of research and into the research findings which have so far been forthcoming.
Stadtentwicklung in der VR China — geschlossene und offene Phasen der Urbanisierung
Authors: Taubmann Wolfgang
Published: March 2010

The traditional Chinese city was considered by the Chinese Communist Party to be the very embodiment of the feudal system; “consumer cities” were, therefore, to be transformed into “producer cities”. However, at a time when the prime focus was on building up Chinese industry, this slogan was less the aim of a new urbanisation strategy than a matter of the cities being seen as low-cost locations for industrial development. Even though living conditions in the cities were impoverished, urbanisation nonetheless repeatedly unleashed waves of migration from the countryside into the cities. Chinese society was split into a rural population and an urban population. Only with the economic reforms of the late ’70s did these structures slowly begin to dissolve.
Die Ausbildung zum Raumplaner
Authors: Wolf Klaus
Published: March 2010

The course leading to the Diploma in Geography at the University of Frankfurt am Main is predicated upon a spatial evaluation of the relationship linking man with his environment. During the foundation phase of the course students are familiarised with the various methods of analysis and evaluation relevant to the field; during the subsequent main section of the course the focus is to a much greater extent on project work, in which students practise working on authentic situations from the professional fields they are expected to enter. In terms of content, individual courses concentrate on four fields, all of which can be subsumed under the watchword of “sustainable spatial development”: the geography of the natural landscape (landscape balance, exploration and analysis of the subsoil), the geography of the everyday world (the individual and housing, leisure, identity), business and logistics, and structures in the third world.
Regional Governance im „Schatten der Hierarchie”
Authors: Diller Christian
Published: March 2010

Differing from the requirements implied in the term “autonomous regional development”, regional governance is almost always dependent on public support. This raises the question of the appropriate “state-run guidance” for these regional governance structures. The article outlines the particularly efficient governance mode of “network-based co-operative negotiations in the shadow of hierarchy” as well as some typical forms of action and problems of state and regional planning in the support of regional governance. Taking the concepts for cities and their surrounding areas in Schleswig-Holstein as examples, it is shown that the careful construction of a “shadow of hierarchy” is a central precondition for successful regional co-operation. It is exactly the combination of public policy- and development policy aspects that makes this type of regional governance attractive and qualifies state and regional planning as its mentor.
Lebensbedingungen im demographischen Wandel
Authors: Schmitz-Veltin Ansgar
Published: March 2010

For decades the regional development of the Federal Republic of Germany based on the goal of equality of living conditions. Today the adjustment of living conditions in urban and rural areas is mainly fulfilled. Nevertheless, the demographic change, the ageing and shrinking of the population, results in a dismantling of infrastructures in weak populated regions and leads so to a new disadvantage of rural residences. At the example of educational infrastructure and medical care in rural regions the possible consequences of this development are examined.
Utility of narrow band imaging for identification of the orifice of the bile duct during ERCP
Authors: Anjiki Hajime , Kamisawa Terumi , Egawa Naoto
Published: March 2010

Exact identification of the orifice of the bile duct in the major duodenal papilla is required for selective cannulation during endoscopic retrograde cholangiopancreatography (ERCP). However, there are some cases in which the orifice is unclear. The narrow band imaging (NBI) system is an endoscopic imaging technique based on modification of spectral features that enhances visualization of the vascular network. On NBI, bile appears as a bright red fluid, and it is enhanced in the digestive tract. We report two cases in which the NBI was useful for identification of the orifice of the bile duct during ERCP. We recommend the NBI technique before cannulation in cases where the orifice is unclear on the standard image.
Délocaliser L'esprit
Authors: Chauviré Christiane
Published: March 2010

Les sciences cognitives ont redonné de l’actualité au vieux problème des localisations cérébrales, qui a souvent été un motif à plaisanteries. Quant à la question plus philosophique de la localisation de l’esprit, des auteurs comme Peirce, James, Wittgenstein et actuellement Vincent Descombes, ont imaginé délocaliser l’esprit, pour mieux réputer dénuée de sens l’idée même d’un lieu du mental et critiquer le localisationnisme qu’on retrouve chez les cogniticiens aujourd’hui.
George Herbert Mead
Authors: Quéré Louis
Published: March 2010

Pour George Herbert Mead, penser c’est entretenir « une conversation de gestes intériorisée». Cette conception ne paraît pas à première vue d’une originalité absolue. Ce qui la rend vraiment originale est l’approche « sociale-behavioriste » dont elle fait partie, et notamment la double idée que la conversation dont il s’agit est une conversation de gestes ou d’attitudes, et que la pensée ainsi quel ‘intelligence réflexive naissent de l’internalisation d’un processus d’organisation de la conduite étayé sur le mécanisme social de la communication. Encore faut-il saisir en quoi cette conception diffère de celle du fondateur de la psychologie behavioriste, John B. Watson, pour qui penser n’est rien d’autre que se tenir un discours interne
John Dury's Apocalyptic Thought: A Reassessment
Authors: GIBSON KENNETH
Published: March 2010

The Protestant divine John Dury has long been identified as holding millenarian beliefs. However a closer reading of his apocalyptic commentaries and a more clearly defined use of terms reveals that Dury's apocalyptic beliefs are more complex than previously recognised. This article offers a detailed analysis of his preface to the European millenarian tract Clavis apocalyptica to demonstrate that apocalyptic and millenarian belief in the seventeenth century is in need of a careful reassessment.
The Seven Sorrows of the Virgin Mary: Devotional Communication and Politics in the Burgundian-Habsburg Low Countries,c.1490–1520
Authors: SUTCH SUSIE SPEAKMAN , VAN BRUAENE ANNE-LAURE
Published: March 2010

This article discusses the propagation of the devotion of the Seven Sorrows of the Virgin Mary in the Low Countries around 1500. The central argument is that the secular goal of the promoters of the devotion was to create a large spiritual and emotional community in support of the Burgundian-Habsburg dynasty and its ideology of peace and territorial unity. To this end a whole array of old and new media was exploited. The article analyses the dynamics of this devotional communication and gives special attention to the role of miracles, vernacular theatre and the printing press.
Experiments on gravity currents propagating down slopes. Part 2. The evolution of a fixed volume of fluid released from closed locks into a long, open channel
Authors: MAXWORTHY T.
Published: March 2010

A series of experiments have been carried out on gravity currents released from locks of various dimensions into a sloping, open channel. Initially all the driving heads of the gravity currents grew by addition of heavier material from a following down-slope flow and by entrainment of ambient fluid, as in Maxworthy & Nokes (J. Fluid Mech., vol. 584, 2007, pp. 433–453). After propagating a distance of the order of 5–10 lock lengths the inflow into the rear stopped, and the head began to lose buoyancy-containing fluid from its rear by the detachment of large, weakly vortical structures. At the same time it was still entraining fluid over the majority of its surface so that its mean density was reduced. Measurements using a semi-direct method, in which dye concentration was used as a surrogate for density, have shown that the buoyancy in the current head increased during the first phase and decreased during the second. At no stage was the buoyancy constant except, of course, at the location and time at which the buoyancy was maximum with a magnitude significantly smaller than the initial value in the lock. Despite this the constant buoyancy theory of Beghin, Hopfinger & Britter (J. Fluid Mech., vol. 107, 1981, pp. 407–422), in which the head location x varies with time t as t2/3 during the later velocity-decay stage of the evolution, was found to be remarkably robust as a description of the evolution over both the latter part of the increasing-buoyancy stage and all of the decreasing-buoyancy phase. Critically, however, the multiplying coefficient had to be smaller than presented by them in order to track the experimental data with precision. This was due principally to the observation that the buoyancy at the beginning of the decay phase was considerably smaller than the initial buoyancy in the lock.
Flow and instability of thin films on a cylinder and sphere
Authors: TAKAGI DAISUKE , HUPPERT HERBERT E.
Published: March 2010

We investigate the dynamics of thin films driven by gravity on the outer surface of a cylinder and sphere. The surface is rigid, stationary and the axis of the cylinder is horizontal. An instantaneous release of a constant volume of fluid at the top of the cylinder or sphere results initially in a two-dimensional or axisymmetric current respectively. The resultant flow of a thin film of fluid is described using lubrication theory when gravity and viscous forces govern the dynamics. We show that the thickness of the flow remains uniform in space and decreases in time liket−1/2near the top of both the cylinder and the sphere. Analytic solutions for the extent of the flow agree well with our experiments until the advancing front splits into a series of rivulets. We discuss scalings of the flow at the onset of the instability as a function of the Bond number, which characterizes the relative importance of gravity and surface tension. The experiments, conducted within an intermediate range of Bond numbers, suggest that the advancing front becomes unstable after it has propagated a critical distance, which depends primarily and monotonically on the volume of fluid and not on the viscosity of fluid. Releasing a sufficiently large volume of fluid ensures that rivulets do not develop on either a cylinder or sphere.
Amplification of enstrophy in the far field of an axisymmetric turbulent jet
Authors: BUXTON O. R. H. , GANAPATHISUBRAMANI B.
Published: March 2010

The amplification of enstrophy is explored using cinematographic stereoscopic particle image velocimetry data. The enstrophy production rate is investigated by observation of the statistical tendency of the vorticity vector (ω) to align with the eigenvectors of the rate of strain tensor (ei). Previous studies have shown thatωpreferentially aligns with the intermediate strain-rate eigenvector (e2) and is arbitrarily aligned with the extensive strain-rate eigenvector (e1). This study shows, however, that the nature of enstrophy amplification, whether it is positive (enstrophy production) or negative (enstrophy destruction), is dictated by the alignment betweenωande1. Parallel alignment leads to enstrophy production (ωiSijωj>0), whereas perpendicular alignment leads to enstrophy destruction (ωiSijωj<0). In this way, the arbitrary alignment betweenωande1is the summation of the effects of enstrophy producing and enstrophy destroying regions. The structure of enstrophy production is also examined with regards to the intermediate strain-rate eigenvalue,s2. Enstrophy producing regions are found to be topologically ‘sheet-forming’, due to an extensive (positive) value ofs2in these regions, whereas enstrophy destroying regions are found to be ‘spotty’. Strong enstrophy producing regions are observed to occur in areas of strong local swirling as well as in highly dissipative regions. Instantaneous visualizations, produced from the volume of data created by Taylor's hypothesis, reveal that these ‘sheet-like’ strong enstrophy producing regions encompass the high enstrophy, strongly swirling ‘worms’. These ‘worms’ induce high local strain fields leading to the formation of dissipation ‘sheets’, thereby revealing enstrophy production to be a complex interaction between rotation and strain – the skew-symmetric and symmetric components of the velocity gradient tensor, respectively.
Modulation of isotropic turbulence by particles of Taylor length-scale size
Authors: LUCCI FRANCESCO , FERRANTE ANTONINO , ELGHOBASHI SAID
Published: March 2010

This study investigates the two-way coupling effects of finite-size solid spherical particles on decaying isotropic turbulence using direct numerical simulation with an immersed boundary method. We fully resolve all the relevant scales of turbulence around freely moving particles of the Taylor length-scale size, 1.2≤d/λ≤2.6. The particle diameter and Stokes number in terms of Kolmogorov length- and time scales are 16≤d/η≤35 and 38≤τp/τk≤178, respectively, at the time the particles are released in the flow. The particles mass fraction range is 0.026≤φm≤1.0, corresponding to a volume fraction of 0.01≤φv≤0.1 and density ratio of 2.56≤ρp/ρf≤10. The maximum number of dispersed particles is 6400 for φv=0.1. The typical particle Reynolds number is of O(10). The effects of the particles on the temporal development of turbulence kinetic energy E(t), its dissipation rate (t), its two-way coupling rate of change Ψp(t) and frequency spectra E(ω) are discussed.

In contrast to particles with d < η, the effect of the particles in this study, with d > η, is that E(t) is always smaller than that of the single-phase flow. In addition, Ψp(t) is always positive for particles with d > η, whereas it can be positive or negative for particles with d < η.
Direct numerical simulation of separated flow in a three-dimensional diffuser
Authors: OHLSSON JOHAN , SCHLATTER PHILIPP , FISCHER PAUL F. , HENNINGSON DAN S.
Published: March 2010

A direct numerical simulation (DNS) of turbulent flow in a three-dimensional diffuser at Re = 10000 (based on bulk velocity and inflow-duct height) was performed with a massively parallel high-order spectral element method running on up to 32768 processors. Accurate inflow condition is ensured through unsteady trip forcing and a long development section. Mean flow results are in good agreement with experimental data by Cherry et al. (Intl J. Heat Fluid Flow, vol. 29, 2008, pp. 803–811), in particular the separated region starting from one corner and gradually spreading to the top expanding diffuser wall. It is found that the corner vortices induced by the secondary flow in the duct persist into the diffuser, where they give rise to a dominant low-speed streak, due to a similar mechanism as the ‘lift-up effect’ in transitional shear flows, thus governing the separation behaviour. Well-resolved simulations of complex turbulent flows are thus possible even at realistic Reynolds numbers, providing accurate and detailed information about the flow physics. The available Reynolds stress budgets provide valuable references for future development of turbulence models.
Preface
Authors: McFadden Geoffrey , Steen Paul , Worster Grae
Published: March 2010

This volume is dedicated to Professor Stephen H. Davis on the occasion of his seventieth birthday. Steve, as he is known to his many friends and colleagues, has served the fluid mechanics community for a good part of those seventy years. He has been distinguished by election to the National Academy of Engineering and the National Academy of Sciences of the USA. A variety of professional societies have honoured Steve, including the American Physical Society, with the Fluid Dynamics Prize in 1994, and the Society of Engineering Sciences, with the G. I. Taylor Medal in 2001. Among a number of named lectureships, he was selected as the G. K. Batchelor Lecturer in 2003 at the University of Cambridge; this is an honour that befits the third scholar to enjoy a dedicated volume of Journal of Fluid Mechanics (JFM), following those dedicated to George Batchelor himself in 1990 (volume 212) and to Philip Saffman in 2000 (volume 409). Steve's editorial services have benefitted the Annual Review of Fluid Mechanics, the Proceedings of the Royal Society of London, SIAM Monographs on Mathematical Modeling and Computation, and the Cambridge University Press Monographs in Mechanics. However, the community to benefit most from Steve's editorial leadership has surely been the authors and readers of JFM. Steve served as an assistant editor and then associate editor for twenty years, from 1969 to 1989, and then returned as editor of the Journal in 2000.