bluuebunny/crossref_metadata_2025_split huggingface dataset:
Endocrine-disrupting effects of spironolactone in female western mosquitofish, Gambusia affinis
Authors: Raut Samiksha A , Howell W. Mike , Angus Robert A 
Published: February 2011

Abstract
The discovery of pharmaceuticals in effluent from wastewater treatment plants and drug manufacturing facilities and in receiving waters has raised environmental concern. Because these compounds are ending up in the environment, it is important to investigate the effects of these compounds on wildlife as well as humans. The present study used a fish model to investigate the endocrine-disrupting effects of spironolactone (SPL), an aldosterone antagonist used as a diuretic, but which also exhibits antiandrogenic effects in humans. A dose–response study measured the effects of SPL on anal fin ray elongation, an androgen-dependent secondary sex trait, and expression of the vitellogenin gene, an estrogen-dependent trait, in female western mosquitofish, Gambusia affinis. Fish were exposed to SPL in the water for 35 d at four nominal concentrations: 10, 100, 250, and 500 nM (4.2, 41.7, 104.1, and 208.3 µg/L, respectively) via the static renewal method. Masculinization of females, as evidenced by development of an elongated and modified anal fin, was observed in the fish exposed to the three highest concentrations. Anal fin elongation was observed in the group exposed to the lowest SPL concentration, but without the development of a tip apparatus. These results confirm the results of a preliminary study that, in contrast to antiandrogenic effects seen in humans, SPL has androgenic and/or antiestrogenic activity in a fish. Environ. Toxicol. Chem. 2011; 30:1376–1382. © 2011 SETAC
EROD activity in peripheral blood lymphocytes and 1-hydroxypyrene in urine and milk as biomarkers of PAH exposure in dairy ruminants
Authors: Guiavarc'h Yann P , Chahin Abir , Dziurla Marie-Antoinette , Yen Frances T , Jondreville Catherine , Rychen Guido 
Published: February 2011

Abstract
Presently, few biomarker-based approaches are available for the evaluation of environmental exposure to persistent organic pollutants in dairy ruminants. In this study, goats (Capra hircus) were orally administered a mixture of pyrene, phenanthrene, and benzo[a]pyrene daily over a 40-d period (1 or 50 mg/d). Milk and urine 1-hydroxypyrene levels, ethoxyresorufin-O-deethylase (EROD) activity in peripheral blood lymphocytes (PBL) as well as urinary levels of 2- and 3-hydroxyphenanthrene were determined at 10-d intervals. 1-Hydroxypyrene excretion in milk and urine significantly increased and then achieved a plateau at 10 d. Transfer rates of 1-hydroxypyrene were calculated to be approximately 0.5 and 25% in milk and urine, respectively. Concentrations in milk and urine were proportional to the ingested doses. These results demonstrate that 1-hydroxypyrene in milk or urine may be used as a biomarker for evaluating the exposure of dairy ruminants to polycyclic aromatic hydrocarbons (PAHs) over an extended exposure period. Constitutive EROD activity in lymphocytes was 0.5 ± 0.3 pmol resorufin/min/mg protein, and was significantly induced over the entire exposure time, before stabilizing after 40 d at 6.30 ± 1.3 and 18.89 ± 1.12 pmol resorufin/min/mg protein for 1 mg/d and 50 mg/d doses, respectively. Induction kinetics were calculated using a logistic-like model and approximate dose–response curves were designed. We therefore propose EROD activity in PBL as a relevant, convenient, and noninvasive biomarker of subchronic exposure of dairy ruminants to CYP450 inducing PAH. Environ. Toxicol. Chem. 2011; 30:1346–1353. © 2011 SETAC
Occurrence and source apportionment of sulfonamides and their metabolites in Liaodong Bay and the adjacent Liao River basin, North China
Authors: Jia Ai , Hu Jianying , Wu Xiaoqin , Peng Hui , Wu Shimin , Dong Zhaomin 
Published: February 2011

Abstract
The presence of antibiotics in the environment is of great concern because of their potential for resistance selection among pathogens. In the present study we investigated the occurrence of 19 sulfonamides, five N-acetylated sulfonamide metabolites, and trimethoprim in the Liao River basin and adjacent Liaodong Bay, China, as well as 10 human/agricultural source samples. Within the 35 river samples, 12 sulfonamides, four acetylated sulfonamides, and trimethoprim were detected, with the dominant being sulfamethoxazole (66.6 ng/L), N-acetylsulfamethoxazole (63.1 ng/L), trimethoprim (29.0 ng/L), sulfadiazine (14.0 ng/L), and sulfamonomethoxine (8.4 ng/L); within the 36 marine samples, 10 chemicals were detected, with the main contributions from sulfamethoxazole (25.2 ng/L) and N-acetylsulfamethoxazole (28.6 ng/L). Sulfamethoxazole (25.9%), N-acetylsulfamethoxazole (46.6%), trimethoprim (22.9%), and sulfapyridine (1.4%) were the main chemicals from human sources, while sulfamonomethoxine, sulfamethazine, sulfaquinoxaline, sulfaguanidine, sulfadiazine, sulfanilamide, and sulfamethoxypyridazine were dominant in the animal husbandry sources, specifically, swine and poultry farms, and sulfamethoxazole (91%) was dominant in the mariculture source. A principal component analysis with multiple linear regression was performed to evaluate the source apportionment of total sulfonamides in Liaodong Bay. It was found that animal husbandry contributed 15.2% of total sulfonamides, while human sources contributed 28.5%, and combined human and mariculture sources contributed 56.3%. In addition, the mariculture contribution was 24.1% of total sulfonamides into the sea based on mass flux estimation. The present study is the first report that the environmental levels of sulfonamide metabolites were comparable to the corresponding parents; therefore, we should pay attention to their environmental occurrence. Source apportionment showed human discharge (60.7%) significantly contributed to these antibiotics in Liaodong Bay, which provides important information for environmental management. Environ. Toxicol. Chem. 2011; 30:1252–1260. © 2011 SETAC
Effects of time-variable exposure regimes of the insecticide chlorpyrifos on freshwater invertebrate communities in microcosms
Authors: Zafar Mazhar Iqbal , Van Wijngaarden Rene P.A , Roessink Ivo , Van den Brink Paul J 
Published: February 2011

Abstract
The present study compared the effects of different time-variable exposure regimes having the same time-weighted average (TWA) concentration of the organophosphate insecticide chlorpyrifos on freshwater invertebrate communities to enable extrapolation of effects across exposure regimes. The experiment was performed in outdoor microcosms by introducing three different regimes: a single application of 0.9 µg active ingredients (a.i.)/L; three applications of 0.3 µg a.i./L, with a time interval of 7 d; and continuous exposure to 0.1 µg a.i./L for 21 d. Measurements showed that the TWA21d concentration in the continuous-exposure treatment (0.098 µg/L) was slightly lower than in the three-application (0.116 µg/L) and single-application (0.126 µg/L) treatments. The application of chlorpyrifos resulted in decreased abundances in the arthropod community, with the largest adverse effects reported for the mayfly Cloeon dipterum and cladocerans Daphnia gr. longispina and Alona sp., while smaller effects were observed for other insects, copepods, and amphipods. At the population level, however, the mayfly C. dipterum only responded to the single-application treatment, which could be explained by the toxicokinetics of chlorpyrifos in this species. At the end of the experimental period the invertebrate community showed approximately the same effect magnitude for all treatment regimes. These results suggest that for this combination of concentrations and duration of the TWA, the TWA concentration is more important for most species than the peak concentration for the assessment of long-term risks of chlorpyrifos. Environ. Toxicol. Chem. 2011; 30:1383–1394. © 2011 SETAC
Comparison of polymeric samplers for accurately assessing PCBs in pore waters
Authors: Gschwend Philip M , MacFarlane John K , Reible Danny D , Lu X , Hawthorne Steven B , Nakles David V , Thompson Timothy 
Published: February 2011

Abstract
Assessing the hazard posed by sediments contaminated with hydrophobic organic compounds is difficult, because measuring the freely dissolved porewater concentrations of such low-solubility chemicals can be challenging, and estimating their sediment–water partition coefficients remains quite uncertain. We suggest that more accurate site assessments can be achieved by employing sampling devices in which polymers, with known polymer–water partition coefficients, are used to absorb the contaminants from the sediment. To demonstrate the current accuracy and limitations of this approach, we compared use of three polymers, polydimethylsiloxane, polyoxymethylene, and polyethylene, exposed to a single sediment in two modes, one in which they were exhaustively mixed (tumbled) with the sediment and the other in which they were simply inserted into a static bed (passive). Comparing porewater concentrations of specific polychlorinated biphenyl (PCB) congeners with results obtained using air bridges, we found the results for tumbled polymers agreed within 20%, and the passive sampling agreed within a factor of 2. In contrast, porewater estimates based on sediment concentrations normalized to fOCKOC, the weight fraction of organic carbon times the organic–carbon normalized partition coefficient, averaged a factor of 7 too high. We also found good correlations of each polymer's uptake of the PCBs with bioaccumulation by the polychaete, Neanthes arenaceodentata. Future improvements of the passive sampling mode will require devices that equilibrate faster and/or have some means such as performance reference compounds to estimate mass transfer limitations for individual deployments. Environ. Toxicol. Chem. 2011; 30:1288–1296. © 2011 SETAC
Effects on tree swallows exposed to dioxin-like compounds associated with the Tittabawassee River and floodplain near Midland, Michigan, USA
Authors: Fredricks Timothy B , Zwiernik Matthew J , Seston Rita M , Coefield Sarah J , Tazelaar Dustin L , Roark Shaun A , Kay Denise P , Newsted John L , Giesy John P 
Published: February 2011

Abstract
Concentrations of dioxin-like compounds, primarily polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzo-p-dioxins (PCDDs), in soils and sediments downstream of Midland, Michigan (USA) were greater than upstream sites and prompted a site-specific hazard assessment of tree swallows breeding in the associated floodplains. Potential for adverse population-level effects from site-specific contaminant exposures were evaluated at study areas (SAs) along the Tittabawassee and Saginaw rivers downstream of Midland. The site-specific multiple lines of evidence approach to hazard assessment included endpoints for dietary- and tissue-based exposures, and population productivity measurements for tree swallows ([TS]; Tachycineta bicolor) measured during the 2005, 2006, and 2007 breeding seasons. Exposure to dioxin-like compounds in TS eggs were some of the greatest recorded and were similar among all upstream and downstream study sites. Conversely, concentrations in nestlings from SAs were significantly greater compared to reference areas (RAs). The pattern of relative concentrations of PCDD/DFs in eggs and nestlings at RAs was dominated by dioxin congeners, whereas at SAs it was dominated by furan congeners. No statistically significant differences were noted in exposure to PCDD/DFs or in population-level responses when compared among locations, and total clutch failures were rare. Hatching success and fledging success were weakly negatively correlated with concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQs) in individual eggs and nestlings, respectively. On-site concentrations of TEQs in floodplain soils were some of the greatest ever reported in the environment, and several lines of evidence indicate potential population-level effects on TS overall reproductive productivity. Environ. Toxicol. Chem. 2011; 30:1354–1365. © 2011 SETAC
A short life-cycle test with the epibenthic copepod Nitocra spinipes for sediment toxicity assessment
Authors: Perez-Landa Victor , Simpson Stuart L 
Published: February 2011

Abstract
A new short life-cycle test methodology is presented to evaluate sublethal effects of contaminated sediments to the harpacticoid copepod species Nitocra spinipes. The method combines a 4-d survival-gravidity test with a 7-d development test. For water-only Cu exposures, the sensitivity of the development test endpoints were compared with tests using nonexposed gravid females to initiate the 7-d development test phase, and also with a multiple generation test comprising three successive phases: 9-d development; 21-d survival-gravidity; second-generation 9-d development. The results indicated that the development endpoints were the most sensitive, with median effective concentration (EC50) values of 95 µg Cu/L for nauplii/gravid female and 101 µg Cu/L copepodites/gravid female endpoints, followed by the gravidity (144 µg Cu/L) and survival (347 µg Cu/L). The sensitivity of the short life-cycle test endpoints was similar to the multiple-generation test endpoints, and the shorter test had less variability in controls. The multiple-generation test showed a large amount of stimulation of reproduction and development at Cu concentrations of 50 to 100 µg/L. The suitability of the short life-cycle test for assessing sediment toxicity was demonstrated using Cu-spiked and naturally contaminated whole sediments. Although the small nauplii were more difficult to isolate from sediments, the small amounts of sediments used for the tests and the large effects of the contaminated sediments on nauplii and copepodite numbers resulted in significant differences to controls. For sediment exposures, the sensitivity of the endpoints was in the order development &gt; gravidity &gt; survival. The short life-cycle test was demonstrated to detect, within 11 d of exposure, similar levels of effects on reproduction and development to those detected using a 39-d multiple-generation exposure. Environ. Toxicol. Chem. 2011; 30:1430–1439. © 2011 SETAC
Forecasting Stock Market Volatility in Central and Eastern European Countries
Authors: Harrison Barry , Moore Winston 
Published: February 2011

ABSTRACTIn recent years, considerable attention has focused on modelling and forecasting stock market volatility. Stock market volatility matters because stock markets are an integral part of the financial architecture in market economies and play a key role in channelling funds from savers to investors. The focus of this paper is on forecasting stock market volatility in Central and East European (CEE) countries. The obvious question to pose, therefore, is how volatility can be forecast and whether one technique consistently outperforms other techniques. Over the years a variety of techniques have been developed, ranging from the relatively simple to the more complex conditional heteroscedastic models of the GARCH family. In this paper we test the predictive power of 12 models to forecast volatility in the CEE countries. Our results confirm that models which allow for asymmetric volatility consistently outperform all other models considered. Copyright © 2011 John Wiley & Sons, Ltd.
Influence of Pressurisation on SOFC Performance and Durability: A Theoretical Study
Authors: Henke M. , Kallo J. , Friedrich K. A. , Bessler W. G. 
Published: February 2011

AbstractHybrid power plants consisting of a solid oxide fuel cell (SOFC) and a gas turbine show high electrical efficiencies, however require pressurisation of the SOFC to several bar. This paper presents a theoretical investigation of the pressure influence on SOFC performance and durability. A two‐dimensional elementary kinetic model is used to predict the performance of a single cell in the pressure range of 1–20 bar. The influence of pressure on thermodynamics, reaction kinetics, porous electrode diffusion, channel transport and efficiency is assessed. It was found that polarisation resistance decreases with increasing pressure due to increased diffusion through porous electrodes and a higher electrode surface coverage with reactant species. Furthermore, open‐circuit voltage increases slightly with pressure. As a consequence, power density and efficiency increase upon pressurisation with the strongest increase at low pressures between 1 and 5 bar. The influence of pressure on two typical degradation mechanisms, nickel oxidation and carbon deposition, is assessed using thermodynamic simulations. Pressurisation facilitates nickel oxidation whereas its effect on carbon deposition strongly depends on temperature.
Preparation of BaZr0.1Ce0.7Y0.2O3–δ Based Solid Oxide Fuel Cells with Anode Functional Layers by Tape Casting
Authors: Nien S. H. , Hsu C. S. , Chang C. L. , Hwang B. H. 
Published: February 2011

AbstractSolid oxide fuel cells (SOFCs) based on the proton conducting BaZr0.1Ce0.7Y0.2O3–δ (BZCY) electrolyte were prepared and tested in 500–700 °C using humidified H2 as fuel (100 cm3 min–1 with 3% H2O) and dry O2 (50 cm3 min–1) as oxidant. Thin NiO‐BZCY anode functional layers (AFL) with 0, 5, 10 and 15 wt.% carbon pore former were inserted between the NiO‐BZCY anode and BZCY electrolyte to enhance the cell performance. The anode/AFL/BZCY half cells were prepared by tape casting and co‐sintering (1,300 °C/8 h), while the Sm0.5Sr0.5CoO3–δ (SSC) cathodes were prepared by thermal spray deposition. Well adhered planar SOFCs were obtained and the test results indicated that the SOFC with an AFL containing 10 wt.% pore former content showed the best performance: area specific resistance as low as 0.39 Ω cm2 and peak power density as high as 0.863 W cm–2 were obtained at 700 °C. High open circuit voltages ranging from 1.00 to 1.12 V in 700–500 °C also indicated negligible leakage of fuel gas through the electrolyte.
Physiologic and anatomic characterization of the brain surface glia barrier of Drosophila
Authors: Desalvo Michael K. , Mayer Nasima , Mayer Fahima , Bainton Roland J. 
Published: February 2011

AbstractCentral nervous system (CNS) physiology requires special chemical, metabolic, and cellular privileges for normal function, and blood–brain barrier (BBB) structures are the anatomic and physiologic constructs that arbitrate communication between the brain and body. In the vertebrate BBB, two primary cell types create CNS exclusion biology, a polarized vascular endothelium (VE), and a tightly associated single layer of astrocytic glia (AG). Examples of direct action by the BBB in CNS disease are constantly expanding, including key pathophysiologic roles in multiple sclerosis, stroke, and cancer. In addition, its role as a pharmacologic treatment obstacle to the brain is long standing; thus, molecular model systems that can parse BBB functions and understand the complex integration of sophisticated cellular anatomy and highly polarized chemical protection physiology are desperately needed. Compound barrier structures that use two primary cell types (i.e., functional bicellularity) are common to other humoral/CNS barrier structures. For example, invertebrates use two cell layers of glia, perineurial and subperineurial, to control chemical access to the brain, and analogous glial layers, fenestrated and pseudocartridge, to maintain the blood–eye barrier. In this article, we summarize our current understanding of brain‐barrier glial anatomy in Drosophila, demonstrate the power of live imaging as a screening methodology for identifying physiologic characteristics of BBB glia, and compare the physiologies of Drosophila barrier layers to the VE/AG interface of vertebrates. We conclude that many unique BBB physiologies are conserved across phyla and suggest new methods for modeling CNS physiology and disease. © 2011 Wiley‐Liss, Inc.
Comparative study on the response of rat primary astrocytes and microglia to methylmercury toxicity
Authors: Ni Mingwei , Li Xin , Yin Zhaobao , Sidoryk‐Węgrzynowicz Marta , Jiang Haiyan , Farina Marcelo , Rocha Joao B. T. , Syversen Tore , Aschner Michael 
Published: February 2011

AbstractAs the two major glial cell types in the brain, astrocytes and microglia play pivotal but different roles in maintaining optimal brain function. Although both cell types have been implicated as major targets of methylmercury (MeHg), their sensitivities and adaptive responses to this metal can vary given their distinctive properties and physiological functions. This study was carried out to compare the responses of astrocytes and microglia following MeHg treatment, specifically addressing the effects of MeHg on cell viability, reactive oxygen species (ROS) generation and glutathione (GSH) levels, as well as mercury (Hg) uptake and the expression of NF‐E2‐related factor 2 (Nrf2). Results showed that microglia are more sensitive to MeHg than astrocytes, a finding that is consistent with their higher Hg uptake and lower basal GSH levels. Microglia also demonstrated higher ROS generation compared with astrocytes. Nrf2 and its downstream genes were upregulated in both cell types, but with different kinetics (much faster in microglia). In summary, microglia and astrocytes each exhibit a distinct sensitivity to MeHg, resulting in their differential temporal adaptive responses. These unique sensitivities appear to be dependent on the cellular thiol status of the particular cell type. © 2011 Wiley‐Liss, Inc
Age and anxiety and depressive symptoms: the effect on domains of quality of life
Authors: Brown Patrick J. , Roose Steven P. 
Published: February 2011

AbstractObjectivesThe present study investigated whether anxiety and depressive symptomatology moderates the relationship between age and quality of life.MethodsThe study was a community‐based survey using mailed questionnaires conducted within the Department of Psychology at Washington University in St. Louis. The community‐based sample consisted of 443 adults ages 30–98 years recruited from university maintained volunteer registries. Quality of life was assessed using the World Health Organization Quality of Life‐BREF assessment; depression was assessed using 15‐item Geriatric Depression Scale and anxiety was assessed using the Social Interaction Anxiety Scale, a measure of social anxiety.ResultsDepression and anxiety were negatively associated with quality of life in the Psychological and Social domains (all p's < 0.001), but age was not (Psychological, p = 0.07; Social, p = 0.98). In addition to depression and anxiety, age was also associated with quality of life in the other two domains, negatively for the Physical domain and positively for the Environmental domain. These main effects were qualified by significant three‐way interactions in both domains.ConclusionsAlthough both anxiety and depression negatively affect Psychological and Social quality of life, age does not. Environmental quality of life increased with age, while Physical quality of life decreased. The deleterious relationship between anxiety and depressive symptomatology and Physical and Environmental quality of life was moderated by age. Older adults with high levels of anxiety and depressive symptoms reported better Environmental and less severe decrements in Physical quality of life compared with middle‐aged adults with similar symptomatology. Copyright © 2011 John Wiley & Sons, Ltd.