bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mixture toxicity from photosystem II inhibitors on microalgal community succession is predictable by concentration addition
Authors: Porsbring Tobias , Backhaus Thomas , Johansson Per , Kuylenstierna Mats , Blanck Hans 
Published: September 2010

AbstractThe typical pollution situation involves chemical mixtures, and assessing the risks of single chemicals one at a time is not sufficient. Concentration addition (CA) has been suggested as a predictive tool in mixture ecotoxicology. The accuracy of CA for mixtures of similarly acting chemicals has been demonstrated under relatively simple biological conditions in single-species tests. To consider the high diversity of interconnected species in ecosystems, one must evaluate CA on a community level of biological organization. We sampled marine periphyton communities from the west coast of Sweden and exposed them to photosystem II (PSII) inhibiting herbicides for 4 d in the SWIFT test, a semistatic, small-scale laboratory test. During this time, the communities went through an ecological succession, influenced by the toxicants in a concentration-dependent manner. Multidimensional scaling was used to assess similarities in the effects of two different sets of PSII inhibitors on pigment profiles, which reflects the taxonomic structure and the physiological status of the microalgal community. One mixture of structurally congeneric phenylureas and one mixture of non-congeneric PSII inhibitors were tested. All PSII inhibitors and their mixtures caused similar changes in the pigment profiles, demonstrating that they not only have a similar biochemical mechanism of action but also are similarly acting on a community level. Concentration addition accurately predicted the effects of both mixtures over the entire effect range. This demonstrates that chemical congenericity is not required for a high predictive power of CA. Instead, in perfect analogy to the situation in single-species tests, a similar mode of action is a sufficient prerequisite for a successful application of CA. Environ. Toxicol. Chem. 2010;29:2806–2813. © 2010 SETAC
Adsorption of tetracycline on single-walled and multi-walled carbon nanotubes as affected by aqueous solution chemistry
Authors: Ji Liangliang , Chen Wei , Bi Jun , Zheng Shourong , Xu Zhaoyi , Zhu Dongqiang , Alvarez Pedro J. 
Published: September 2010

Abstract
Carbon nanotubes have shown great potential as effective adsorbents for hydrophobic organic contaminants in water treatment. The present study investigated the influence of aqueous solution chemistry on the adsorption of tetracycline to carbon nanotubes. Specifically, the effects of ionic strength (NaCl and CaCl2) and presence of Cu2+ ion (7.5 mg/L) or dissolved soil or coal humic acids (50 mg/L) on adsorption of tetracycline to single-walled carbon nanotubes (SWNT), multi-walled carbon nanotubes (MWNT), and nonporous pure graphite as a model of the graphite surface were systematically estimated. The presence of humic acids suppressed tetracycline adsorption on graphite and MWNT prominently, with stronger effects observed on graphite, but only slightly affected tetracycline adsorption on SWNT. The relatively large humic acid components could not readily access the small interstitial spaces of SWNT and thus were less competitive with tetracycline adsorption. The presence of Cu2+ ion increased tetracycline adsorption to both SWNT and MWNT through the mechanism of cation bridging, with much larger effects observed on MWNT. This was probably because when compared with the Cu2+ ions complexed on the surface of SWNT, those on the surface of MWNT having larger mesoporous interstices were more accessible to the relatively bulky tetracycline molecule. Increasing the ionic strength from 10 mM to 100 mM decreased tetracycline adsorption on both SWNT and MWNT, which was attributed to electronic shielding of the negatively charged surface sites. These results show that aqueous solution chemistry is important to tetracycline adsorption on carbon nanotubes. Environ. Toxicol. Chem. 2010;29:2713–2719. © 2010 SETAC
The value of repeating studies and multiple controls: replicated 28-day growth studies of rainbow trout exposed to clofibric acid
Authors: Owen Stewart F. , Huggett Duane B. , Hutchinson Thomas H. , Hetheridge Malcolm J. , McCormack Paul , Kinter Lewis B. , Ericson Jon F. , Constantine Lisa A. , Sumpter John P. 
Published: September 2010

Abstract
Two studies to examine the effect of waterborne clofibric acid (CA) on growth-rate and condition of rainbow trout were conducted using accepted regulatory tests (Organisation for Economic Co-operation and Development [OECD] 215). The first study (in 2005) showed significant reductions after 21 d of exposure (21-d growth lowest-observed-effect concentration [LOEC] = 0.1 µg/L, 21-d condition LOEC = 0.1 µg/L) that continued to 28 d. Growth rate was reduced by approximately 50% (from 5.27 to 2.67% per day), while the condition of the fish reduced in a concentration-dependant manner. Additionally, in a concentration-dependent manner, significant changes in relative liver size were observed, such that increasing concentrations of CA resulted in smaller livers after 28-d exposure. A no-observed-effect concentration (NOEC) was not achieved in the 2005 study. An expanded second study (in 2006) that included a robust bridge to the 2005 study, with four replicate tanks of eight individual fish per concentration, did not repeat the 2005 findings. In the 2006 study, no significant effect on growth rate, condition, or liver biometry was observed after 21 or 28 d (28-d growth NOEC = 10 µg/L, 28-d condition NOEC = 10 µg/L), contrary to the 2005 findings. We do not dismiss either of these findings and suggest both are relevant and stand for comparison. However, the larger 2006 study carries more statistical power and multiple-tank replication, so probably produced the more robust findings. Despite sufficient statistical power in each study, interpretation of these and similar studies should be conducted with caution, because much significance is placed on the role of limited numbers of individual and tank replicates and the influence of control animals. Environ. Toxicol. Chem. 2010;29:2831–2839. © 2010 SETAC
Comparison of field and laboratory exposures ofLumbriculus variegatusto polychlorinated biphenyl-impacted river sediments
Authors: Beckingham Barbara , Ghosh Upal 
Published: September 2010

AbstractA method is described for conducting 14-d in situ sediment bioaccumulation tests with the freshwater oligochaete Lumbriculus variegatus, at the bottom of a slow-flowing river. The in situ test exposure chambers were constructed from cylindrical plastic tubes with flow-through mesh screens and were attached to a wire basket that was weighted to the river bottom at seven sites in the lower Grasse River in New York State, USA. This design was successful in exposing L. variegatus to native sediment and overlying water under field conditions, with adequate organism mass recovery (87 ± 19%). Results compared well with ex situ laboratory bioaccumulation conducted in parallel, expressed in terms of tissue concentration, biota-sediment accumulation factors (BSAFs), and bioaccumulation factors (BAFs). Bioaccumulation of polychlorinated biphenyls (PCBs) in L. variegatus (µg PCB/g wet wt) in laboratory and field tests was found to be within a factor of 2. The small variation between in situ and ex situ may have been caused by differences in water exchange rate under the two exposure scenarios, or other factors affecting organism behavior. Values of BSAF showed a hyperbolic trend with KOW, peaking at BSAF of 7 for congeners with log KOW of 6. Bioaccumulation factors also peaked at a value of 106.5 for congeners with log KOW value of 6 but remained steady around that value for the higher KOW congeners. These observations may reflect under-equilibration or reduced bioavailability of more hydrophobic PCBs in worm tissues or other analytical artifacts. Environ. Toxicol. Chem. 2010;29:2851–2858. © 2010 SETAC
Assessment of the levels of heavy metal pollution in roadside soils of Eskisehir, Turkey
Authors: Malkoc Semra , Yazıcı Berna , Savas Koparal A. 
Published: September 2010

Abstract
A detailed study was conducted to determine the current status of the heavy metals Cd, Cu, Cr, Fe, Hg, Mn, Ni, Pb, and Zn in Eskisehir, Turkey. The 15 different locations (n = 270) studied were specifically selected to identify the effects of soil pollution on the tramway, which has been in service since December 2004 for public transportation in Eskisehir. The samples were taken from three different lines: tramway-only lines, traffic-only lines, and both traffic and tramway lines. The pollution level was estimated based on the geoaccumulation index (Igeo), the enrichment factor (EF), the pollution index, and the integrated pollution index (IPI). The values for the IPI were in the following order: Pb &gt; Zn &gt; Cu &gt; Fe &gt; Mn &gt; Ni &gt; Cr &gt; Cd, but mercury was not detected at any sample point. These indexes for metals in the soils under consideration correlated with either low or median levels of pollution. In addition, descriptive statistics were provided for the heavy metals under consideration, and box-plots were constructed and interpreted for all measured indices. Environ. Toxicol. Chem. 2010;29:2720–2725. © 2010 SETAC
Use of vegetated agricultural drainage ditches to decrease toxicity of irrigation runoff from tomato and alfalfa fields in California, USA
Authors: Werner Inge , Deanovic Linda A. , Miller Jeff , Denton Debra L. , Crane David , Mekebri Abdou , Moore Matthew T. , Wrysinski Jeanette 
Published: September 2010

AbstractThe current study investigated the potential of vegetated drainage ditches for mitigating the impact of agricultural irrigation runoff on downstream aquatic ecosystems. Water column toxicity to larval fathead minnow (Pimephales promelas),and the amphipod Hyalella azteca was measured for 12 h or less at the ditch inflow and outflow, using custom-built in situ exposure systems. In addition, water and sediment samples were subject to standard toxicity tests with Ceriodaphnia dubia and H. azteca, respectively. No acute toxicity to larval fathead minnow was observed; however, runoff was highly toxic to invertebrates. Passage through a 389- to 402-m section of vegetated ditch had a mitigating effect and reduced toxicity to some degree. However, runoff from an alfalfa field treated with chlorpyrifos remained highly toxic to both invertebrate species, and runoff from a tomato field treated with permethrin remained highly toxic to H. azteca after passage through the ditch. Predicted toxic units calculated from insecticide concentrations in runoff and 96-h median lethal concentration (LC50) values generally agreed with C. dubia toxicity measured in the laboratory but significantly underestimated in situ toxicity to H. azteca. Sediments collected near the ditch outflow were toxic to H. azteca. Results from the current study demonstrate that experimental vegetated ditches were unable to eliminate the risk of irrigation runoff to aquatic ecosystems. In addition, protective measures based on chemical concentrations or laboratory toxicity tests with C. dubia do not ensure adequate protection of aquatic ecosystems from pyrethroid-associated toxicity. Environ. Toxicol. Chem. 2010;29:2859–2868. © 2010 SETAC
Adaptive modelling and forecasting of offshore wind power fluctuations with Markov‐switching autoregressive models
Authors: Pinson Pierre , Madsen Henrik 
Published: September 2010

ABSTRACTWind power production data at temporal resolutions of a few minutes exhibit successive periods with fluctuations of various dynamic nature and magnitude, which cannot be explained (so far) by the evolution of some explanatory variable. Our proposal is to capture this regime‐switching behaviour with an approach relying on Markov‐switching autoregressive (MSAR) models. An appropriate parameterization of the model coefficients is introduced, along with an adaptive estimation method allowing accommodation of long‐term variations in the process characteristics. The objective criterion to be recursively optimized is based on penalized maximum likelihood, with exponential forgetting of past observations. MSAR models are then employed for one‐step‐ahead point forecasting of 10 min resolution time series of wind power at two large offshore wind farms. They are favourably compared against persistence and autoregressive models. It is finally shown that the main interest of MSAR models lies in their ability to generate interval/density forecasts of significantly higher skill. Copyright © 2010 John Wiley & Sons, Ltd.
Estimation of P‐value of MAX test with double triangle diagram for 2 × 3 SNP case‐control tables
Authors: Hirosawa Katsura , Kawaguchi Takahisa , Matsuda Fumihiko , Yamada Ryo 
Published: September 2010

AbstractSingle nucle otide polymorphisms (SNPs) are the most popular markers in genetic epidemiology. Multiple tests have been applied to evaluate genetic effect of SNPs, such as Pearson's test with two degrees of freedom, three tests with one degree of freedom (χ2 tests for dominant and recessive modes and Cockran‐Armitage trend test for additive mode) as well as MAX3 test and MAX test, which are combination of four tests mentioned earlier. Because MAX test is a combination of Pearson's test of two degrees of freedom and two tests of one degree of freedom, the probability density function (pdf) of MAX statistics does not match pdf of χ2 distribution of either one or two degrees of freedom. In order to calculate P‐value of MAX test, we introduced a new diagram, Double Triangle Diagram, which was an extension of de Finetti diagram in population genetics which characterized all of the tests for 2 × 3 tables. In the diagram the contour lines of MAX statistics were consisted of elliptic curves and two tangent lines to the ellipses in the space. We normalized the ellipses into regular circles and expressed P‐value of MAX test in an integral form. Although a part of the integral was not analytically solvable, it was calculable with arbitrary accuracy by dividing the area under pdf into finite rectangles. We confirmed that P‐values from our method took uniform distribution from 0 to 1 in three example marginal count sets and concluded that our method was appropriate to give P‐value of MAX test for 2 × 3 tables. Genet. Epidemiol. 34:543–551, 2010. © 2010 Wiley‐Liss, Inc.
A Bayesian approach to genetic association studies with family‐based designs
Authors: Naylor Melissa G. , Weiss Scott T. , Lange Christoph 
Published: September 2010

AbstractFor genome‐wide association studies with family‐based designs, we propose a Bayesian approach. We show that standard transmission disequilibrium test and family‐based association test statistics can naturally be implemented in a Bayesian framework, allowing flexible specification of the likelihood and prior odds. We construct a Bayes factor conditional on the offspring phenotype and parental genotype data and then use the data we conditioned on to inform the prior odds for each marker. In the construction of the prior odds, the evidence for association for each single marker is obtained at the population‐level by estimating its genetic effect size by fitting the conditional mean model. Since such genetic effect size estimates are statistically independent of the effect size estimation within the families, the actual data set can inform the construction of the prior odds without any statistical penalty. In contrast to Bayesian approaches that have recently been proposed for genome‐wide association studies, our approach does not require assumptions about the genetic effect size; this makes the proposed method entirely data‐driven. The power of the approach was assessed through simulation. We then applied the approach to a genome‐wide association scan to search for associations between single nucleotide polymorphisms and body mass index in the Childhood Asthma Management Program data. Genet. Epidemiol. 34:569–574, 2010. © 2010 Wiley‐Liss, Inc.
Incorporating contaminant bioavailability into sediment quality assessment frameworks
Authors: Maruya Keith A , Landrum Peter F , Burgess Robert M , Shine James P 
Published: September 2010

Abstract
The recently adopted sediment quality assessment framework for evaluating bay and estuarine sediments in the state of California incorporates bulk sediment chemistry as a key line of evidence (LOE) but does not address the bioavailability of measured contaminants. Thus, the chemistry-based LOE likely does not provide an accurate depiction of organism exposure in all cases, nor is it particularly well suited for assessment of causality. In recent years, several methods for evaluating the bioavailability of sediment-associated contaminants have emerged, which, if optimized and validated, could be applied to improve the applicability and broaden the scope of sediment quality assessment. Such methods include equilibrium-based biomimetic extractions using either passive sampling devices (PSDs) or measures of rapidly desorbing contaminant pools, which provide information compatible with existing mechanistic approaches. Currently, these methods show promise in relating bioaccessible chemicals to effects endpoints, including bioaccumulation of hydrophobic organic compounds and/or toxicity due to metals. Using these methods, a bioavailability LOE for organics is proposed based on PSD and equilibrium partitioning theory that can be employed as an independent LOE or in assessing causality in tiered toxicity identification evaluations. Current and future research should be aimed at comparing the performance of PSDs and their relationships with effects concentrations, field validation of the most promising methods, addressing contaminant mixtures, further developing the parameterization of the proposed bioavailability LOE, and providing a better understanding of the underlying diagenetic cycling of metal contaminants that lead to exposure, affect bioavailability, and drive adverse outcomes. Integr Environ Assess Manag 2012; 8: 659–673. © 2010 SETAC
Biomass or growth rate endpoint for algae and aquatic plants: Relevance for the aquatic risk assessment of herbicides
Authors: Bergtold Matthias , Dohmen Gerhard Peter 
Published: September 2010

Abstract
Ecotoxicological studies with algae and aquatic plants are essential parts of the aquatic risk assessment for crop protection products (CPP). Growth rate is used as a response variable and in addition the effects on biomass and/or yield (in the following biomass) can be measured. The parameter biomass generally provides a lower numerical value compared with the growth rate for systematic and mathematical reasons. Therefore, some regulators prefer to use the EbC50 value (i.e., the concentration at which 50% reduction of biomass is observed) rather than ErC50 (the concentration at which a 50% inhibition of growth rate is observed) as the endpoint for ecotoxicological risk assessment. However, the parameter growth rate is scientifically more appropriate and robust against deviations in test conditions, permitting better interpretation of, and comparison between, studies. The aim of the present work is to evaluate the growth rate and biomass parameters with regard to their protectiveness and suitability for environmental risk assessment of CPP. It has been shown for a number of herbicides that the use of the EC50 value (without distinction between growth rate and biomass endpoints) from laboratory studies in combination with an assessment factor of 10 is sufficiently protective for aquatic plants (except for the herbicide 2,4-D). In this paper we evaluated EbC50 and ErC50 values seperately. Data on 19 different herbicides were compiled from the literature or GLP reports. The EbC50 and ErC50 values obtained in laboratory studies were compared with effect concentrations in ecosystem studies (mainly mesocosm). This comparison of laboratory and field data shows that the overall aquatic risk assessment using ErC50 values in combination with the currently applied assessment factor of 10 is sufficient to exclude significant risk to aquatic plants in the environment. Integr Environ Assess Manag 2011;7:237–247. © 2010 SETAC
Changes in the two‐dimensional electrophoresis pattern of the Parkinson's disease related protein DJ‐1 in human SH‐SY5Y neuroblastoma cells after dopamine treatment
Authors: Alberio Tiziana , Colapinto Monica , Natale Massimo , Ravizza Raffaella , Gariboldi Marzia B. , Bucci Enrico M. , Lopiano Leonardo , Fasano Mauro 
Published: September 2010

AbstractDJ‐1 is a mitochondrial protein linked to Parkinson's disease. DJ‐1 has been suggested to have several possible functions, although it has been mainly associated to oxidative stress defence. Changes in the two‐dimensional electrophoresis pattern have been thoroughly described as a consequence of oxidative modification of the Cys106 residue. There is accumulating evidence supporting a specific role of DJ‐1 in protecting dopaminergic neurons from dopamine itself. By exposing SH‐SY5Y human neuroblastoma catecholaminergic cells to dopamine, we observed a specific increase in the most acidic forms in the DJ‐1 two‐dimensional electrophoresis pattern together with a significant decrease of the most basic spot. Unlike cells exposed to generic oxidative conditions, no additional shift was observed. The results are corroborated by a meta‐analysis of the literature showing that in the absence of dopamine treatment the specific acidic form is underrepresented. © 2010 IUBMB IUBMB Life, 62(9): 688–692, 2010
IGF-1 and bone: New discoveries from mouse models
Authors: Yakar Shoshana , Courtland Hayden-William , Clemmons David 
Published: September 2010

Abstract
Insulin-like growth factor-1 (IGF-1) plays a central role in cellular growth, differentiation, survival, and cell cycle progression. It is expressed early during development and its effects are mediated through binding to a tyrosine kinase receptor, the insulin-like growth factor-1 receptor (IGF-1R). In the circulation, the IGFs bind to IGF-binding proteins (IGFBPs), which determine their bioavailability and regulate the interaction between the IGFs and IGF-1R. Studies in animal models and in humans have established critical roles for IGFs in skeletal growth and development. In this review we present new and old findings from mouse models of the IGF system and discuss their clinical relevance to normal and pathological skeletal physiology. © 2010 American Society for Bone and Mineral Research.