bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

AbstractTriorganotin 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

Abstract
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

Abstract
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

Abstract
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 &lt; 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

Abstract
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

Abstract
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

Abstract
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 &gt; 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 &lt; 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

Abstract
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 (&lt;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

Abstract
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.
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

AbstractExact 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.
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.
Superior sagittal sinus thrombosis complicating neck dissection
Authors: Howe D J , Henderson M J , Ahmad I 
Published: March 2010

AbstractObjective:To report a superior sagittal sinus thrombosis occurring as a rare complication of neck dissection, and to present a review of published literature.Case report:A 42-year-old man underwent an elective neck dissection for a tumour stage 2, node stage 2b, tonsillar squamous cell carcinoma, prior to chemoradiotherapy. During surgery, the right internal jugular vein was sacrificed as part of the resection, as tumour was adherent to it. Two weeks after surgery, the patient was readmitted with seizures. Subsequent computed tomography and magnetic resonance venography confirmed a superior sagittal sinus thrombosis. The patient was subsequently anticoagulated and underwent radiotherapy without further complication. A review of pre-operative imaging indicated a dominant internal jugular vein, ligation of which may have been a factor in the subsequent sagittal sinus thrombosis.Conclusion:Superior sagittal sinus thrombosis following neck dissection is a rare occurrence, with little reported in the literature. Dominant internal jugular vein anatomy may be evident on pre-operative imaging. An awareness of this complication may be helpful to surgeons contemplating sacrifice of the internal jugular vein.
Facial emotion recognition in schizotypy: The role of accuracy and social cognitive bias
Authors: BROWN LAURA A. , COHEN ALEX S. 
Published: March 2010

AbstractFacial emotion recognition deficits have been widely investigated in individuals with schizophrenia; however, it remains unclear whether these deficits reflect a trait-like vulnerability to schizophrenia pathology present in individuals at risk for the disorder. Although some studies have investigated emotion recognition in this population, findings have been mixed. The current study uses a well-validated emotion recognition task, a relatively large sample, and examines the relationship between emotion recognition, symptoms, and overall life quality. Eighty-nine individuals with psychometrically defined schizotypy and 27 controls completed the Schizotypal Personality Questionnaire, Penn Emotion Recognition Test, and a brief version of Lehman’s Quality of Life Interview. In addition to labeling facial emotions, participants rated the valence of faces using a Likert rating scale. Individuals with schizotypy were significantly less accurate than controls when labeling emotional faces, particularly neutral faces. Within the schizotypy sample, both disorganization symptoms and lower quality of life were associated with a bias toward perceiving facial expressions as more negative. Our results support previous research suggesting that poor emotion recognition is associated with vulnerability to psychosis. Although emotion recognition appears unrelated to symptoms, it probably operates by means of different processes in those with particular types of symptoms. (JINS, 2010, 16, 474–483.)
Breakfast trends in children and adolescents: frequency and quality
Authors: Alexy Ute , Wicher Meike , Kersting Mathilde 
Published: March 2010

AbstractObjectiveAlthough breakfast is important for obesity prevention and dietary quality, breakfast skipping is a common behaviour. Knowledge of changes in breakfast habits may provide potential behaviour targets for intervention programmes. The present study describes the actual data on trends in breakfast habits and composition.DesignA total of 7800 3 d dietary records of 1081 participants aged 2–18 years collected between 1986 and 2007 in the DONALD (Dortmund Nutritional and Anthropometric Longitudinally Designed) Study were analysed using mixed linear models.ResultsBreakfast was eaten at 78 % of all record days; regular breakfast (breakfast was eaten on all three recorded weekdays) was eaten in 75 % of records. During the study period, the number of records with regular breakfast decreased significantly in 6–12- and 13–18-year-olds (P= 0·0084 and 0·0350, respectively). Of all breakfast meals, 62 % were bread meals and 21 % were ready-to-eat cereal (RTEC) meals. RTEC meals nearly doubled from the youngest to the oldest age group (P< 0·0001). During the study period, the percentage of bread meals decreased, whereas the percentage of RTEC meals increased (P< 0·0001). A higher percentage of RTEC meals than the bread meals was in accordance with the food-based guidelines (36 %v. 20 %,P< 0·0001), i.e. a breakfast including grain, dairy and fruit/vegetables.ConclusionsIn the DONALD Study sample, a negative age and time trend in breakfast consumption was verified. Interventions regarding breakfast habits should be aimed at adolescents and should focus on fruit/vegetables.