bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pesticide and toxicity reduction using an integrated vegetated treatment system
Authors: Anderson Brian , Phillips Bryn , Hunt John , Largay Bryan , Shihadeh Rami , Tjeerdema Ronald 
Published: February 2011

Abstract
The California, USA, central coast is one of the most productive agricultural areas in the world, and numerous stakeholders are working there to implement conservation practices to reduce contaminated runoff. Practices include vegetated treatment systems (VTS) designed to promote contaminant reduction and breakdown. The current study evaluated the effectiveness of a vegetated drainage ditch incorporating a sedimentation basin, a vegetated section, and a Landguard organophosphate-A (OP-A) enzyme dosing system. The VTS was constructed on a working farm and was designed to remove organophosphate and pyrethroid pesticides, the primary pesticides causing toxicity in Salinas Valley watersheds. The present study was conducted during five separate irrigation events on tailwater runoff containing mixtures of pesticides and suspended sediments. Water samples were collected at four stations within the system, and these were subjected to chemical analyses and tested for toxicity to Ceriodaphnia dubia. All inflow samples were highly toxic to C. dubia, and this was largely because of diazinon. Treatment of diazinon-contaminated runoff was only partially effective using aquatic vegetation. All diazinon remaining after vegetated treatment was effectively removed after treatment with the Landguard OP-A enzyme. Chemical analysis of the VTS water samples showed that pyrethroid and organochlorine pesticide concentrations in water were greatly reduced in the sedimentation section of the ditch, and these pesticides were further reduced in the vegetated section of the ditch. The overall conclusion from these analyses is that the VTS was effective at reducing the more hydrophobic organochlorine and pyrethroid pesticides from water. The water-soluble pesticide diazinon was not sufficiently removed during the VTS residence times observed in this study; however, residual diazinon was effectively removed using Landguard OP-A. Environ. Toxicol. Chem. 2011; 30:1036–1043. © 2011 SETAC
Proteomics in aquatic amphipods: Can it be used to determine mechanisms of toxicity and interspecies responses after exposure to atrazine?
Authors: Ralston-Hooper Kimberly J , Sanchez Brian C , Adamec Jiri , Sepúlveda María S 
Published: February 2011

Abstract
Proteomics has gained popularity in the field of ecotoxicology as a holistic tool for unraveling novel mechanisms of toxicity and elucidating subtle effects of contaminant exposure. The holoarctic amphipod Diporeia spp. is declining at precipitous rates in the Great Lakes, and we are evaluating the use of the well-studied amphipod model Hyalella azteca as a surrogate for Diporeia spp. This article presents proteomics data from both amphipod species exposed to atrazine (ATZ) and one of its metabolites, desethylatrazine (DEA; 3 and 30 µg/L for 21 and 42 d). We used a proteomics approach to determine whether these two species of amphipods responded similarly to the same chemicals and to understand better the mechanisms of toxicity of ATZ and DEA in aquatic invertebrates. We observed disruption in energy production and mitochondrial function as well as hormesis in exposed organisms. In addition, we identified a two proteins (GAPDH and HSP 90 kDa) that have been linked to hormonal disruptions, suggesting potential endocrine disruption. Finally, we found that H. azteca and Diporeia spp. responded with similar proteomic profiles after ATZ and DEA exposure, suggesting that H. azteca may be used as a surrogate model organism for Diporeia spp. Environ. Toxicol. Chem. 2011; 30:1197–1203. © 2011 SETAC
Bacterial gene profiling assay applied as an alternative method for mode of action classification: Pilot study using chlorinated anilines
Authors: Dom Nathalie , Nobels Ingrid , Knapen Dries , Blust Ronny 
Published: February 2011

Abstract
Polar narcotic structural analogues (e.g., chlorinated anilines with a differing degree of chlorosubstitution, such as aniline, 4-chloroaniline, 3,5-dichloroaniline, and 2,3,4-trichloroaniline) are assumed to induce their toxic effects via the same predominant mode of action (MOA; membrane damage) at equitoxic exposure concentrations. In this study, a bacterial gene profiling assay consisting of 14 general stress genes was used to test this hypothesis for these four compounds. Although we found a consistent induction of membrane damage, the response cascade and the extent of the response differed among the different chemical treatments. The higher chlorosubstituted anilines also triggered significantly more genes involved in other general stress MOA classes (oxidative stress and protein perturbation). These findings illustrate that, along with the commonly used physicochemistry-based MOA categorization methods, alternative tests such as the bacterial gene profiling assay can yield valuable biological information on the MOA of a certain chemical or group of chemicals that is crucial in high-quality environmental risk assessment. In a second phase, the experimental gene profiling data sets of the chlorinated anilines were analyzed and weighed against existing data on other polar and non polar narcotic compounds to obtain a broader comparison in which the predefined chemical MOAs (narcosis and polar narcosis) were contrasted with the biological MOAs (gene expression profiles). Although additional optimization of the assay is needed, our results show that the bacterial gene profiling assay opens new perspectives for biology-based chemical grouping, thereby further enabling targeted MOA-based risk assessment. Environ. Toxicol. Chem. 2011; 30:1059–1068. © 2011 SETAC
Dissolution and Migration of Platinum in PEMFCs Investigated for Start/Stop Cycling and High Potential Degradation
Authors: Ettingshausen F. , Kleemann J. , Marcu A. , Toth G. , Fuess H. , Roth C. 
Published: February 2011

AbstractDissolution and migration of platinum due to start/stop degradation and increased cathode potentials were studied for commercial membrane electrode assemblies (MEA). The chosen conditions closely mimic real situations in automotive operation. In start/stop tests, we observed a strongly enhanced platinum dissolution due to the dynamic interplay of repeated cell start‐up and consecutive normal fuel cell operation, which is related to platinum oxidation (start‐up) and reduction (normal operation) cycles. Consequently, the performed test protocols distinguish between dynamic and static load profiles. Electrochemical investigations before and after degradation monitor the loss in cell performance. Since electron microscopy offers the unique possibility to unravel and distinguish degradation due to carbon corrosion and agglomeration or platinum dissolution, a focus was set on this method. For the start/stop MEA pronounced platinum dissolution accompanied by the formation of large platinum precipitations in the membrane was found. Carbon corrosion was also observed, but did not lead to a significantly reduced porosity and loss in platinum dispersion. In contrast, the MEA which was exposed to high constant potentials exhibited severe damage to the 3D cathode structure due to carbon corrosion. However, no pronounced platinum dissolution was observed and only few Pt precipitations were found in the membrane itself.
Raman Spectroscopic Mapping of the Carbon and PTFE Distribution in Gas Diffusion Layers
Authors: Mendoza A. J. , Hickner M. A. , Morgan J. , Rutter K. , Legzdins C. 
Published: February 2011

AbstractRaman microspectroscopy was used to gather spatially resolved chemical information on the carbon and poly(tetrafluoroethylene) (PTFE) distribution of fuel cell gas diffusion layers (GDL). GDLs with varying PTFE content were imaged over areas of 1,000 μm × 1,000 μm and it was found that the distribution of concentrated PTFE regions on the surface of the GDLs and morphology of the carbon fibre paper was readily observed. Spectroscopic measurements with point‐by‐point resolutions varying between 10 and 500 μm were performed on samples having 1.8–44 wt.% PTFE before and after the PTFE was sintered. The average PTFE signal detected on the surface of the GDLs increased monotonically for both unsintered and sintered GDLs with increasing bulk PTFE loading. The unsintered GDLs had higher PTFE signals on their surface compared to sintered GDLs and showed more concentrated PTFE regions in the mapping experiments.
A Two‐dimensional Network Study on Oxygen Transport in Porous Gas Diffusion Layer
Authors: Wu R. , Liao Q. , Zhu X. , Wang H. , Ding Y.‐d. , Li J. , Ye D.‐d. 
Published: February 2011

AbstractOxygen transport in the porous gas diffusion layer (GDL), which is generally characterised by the oxygen effective diffusivity, is of great importance for the performance of proton exchange membrane fuel cells (PEMFCs). The determination of the oxygen effective diffusivity is challenging due to the complex structure of the porous GDL samples. In the present study, a two‐dimensional network consisting of arms and nodes is adopted to illustrate how oxygen effective diffusivity is affected by the GDL structure under the condition with/without water invasion. Water permeation in the network is simulated using the invasion percolation algorithm and oxygen transport in the arms is described by Fick's law. The simulation results reveal that oxygen effective diffusivity under dry condition decreases with increase in the network heterogeneity. With water permeation, the oxygen effective diffusivity goes to zero even though water saturation is rather less than unity. The critical water saturation, above which the oxygen effective diffusivity becomes zero, is found to decrease with increasing heterogeneity. To enhance oxygen transport, four different modified networks are introduced in the present study. It is found that the network with large arms in oxygen transport direction has the best oxygen and water transport properties.
Microscale Modeling of an Anode‐Supported Planar Solid Oxide Fuel Cell
Authors: Chinda P. , Wechsatol W. , Chanchaona S. , Brault P. 
Published: February 2011

AbstractA microscale model of a solid oxide fuel cell (SOFC) involving the mass transfer together with the electrochemical reaction, the transportation of electrons and ions through the respective spherical shaped electron conducting and ion conducting particles inside the electrodes was mathematically developed. Couples of useful parameters were introduced in order to represent the characteristics of the cell. The predicted cell performance was showed according to various operating and design conditions. The effects of microscale electrode geometry on the cell performance were also taken into account. Parametric study according to the volumetric fraction of ionic and electronic conducting particles was conducted in order to examine the effects of operating conditions on the cell overpotentials. The study results substantiate the fact that SOFC overpotential could be effectively decreased by increasing the operating temperature as well as operating pressure. This present study reveals the working mechanisms of SOFC at the microscale level, while demonstrating the use of microscale relations to enhance the SOFC performance. The accuracy of the presented model was validated by comparing with already existing experimental results from the available literatures.
Prevalence and risk factors for depression in older people in Xi′an China: a community‐based study
Authors: Yunming Li , Changsheng Chen , Haibo Tu , Wenjun Cao , Shanhong Fan , Yan Ma , Yongyong Xu , Qianzhen Hua 
Published: February 2011

AbstractObjectiveTo estimate the prevalence of depressive symptoms and to determine the impact of socio‐demographic variables, chronic diseases and health‐related events on depression in a community sample of older adults in Xi′an, Shaanxi Province.MethodsCross sectional, multistage community survey. A semi‐structured questionnaire including socio‐demographic characteristics, physical health, chronic diseases and health‐related events was administered to 1587 older adults from eight communities. Depression was assessed using the 30‐item Geriatric Depression Scale (GDS) with a threshold of <11/11+. Analysis was conducted using SPSS16.0 Complex Samples Logistic analysis procedure.ResultsThe prevalence of depression was 27.0% (95% CI 24.7–29.2%). In a univariate analysis, the following variables were significantly associated with depression: female gender, low max income, coronary heart disease, suffering 3 or above chronic diseases and functional impairments, 4 adverse life events (financial problems, death of closely related person, unpleasantness experience and horrifying experience) and suffering 1 or above adverse life events. After adjustment for age and gender, odds ratios for depression were significantly higher for coronary heart disease, suffering 3 or above chronic diseases and functional impairments, adverse life event (financial problems, unpleasantness experience) and suffering 3 or above adverse life events.ConclusionsAccording to GDS estimates, 27.0% Chinese urban older adult had depression symptoms. In designing prevention programs, detection and management of older patients with depression should be a high priority in developing countries. Copyright © 2011 John Wiley & Sons, Ltd.
Spatial variability and temporal stability of throughfall in a eucalyptus plantation in the hilly lowlands of southeastern Brazil
Authors: Mululo Sato Anderson , de Souza Avelar André , Coelho Netto Ana Luiza 
Published: February 2011

AbstractThroughfall has been widely studied in forests but there is a scarcity of studies that focus on the spatial variability and temporal stability of throughfall in eucalyptus plantations. We examined throughfall in a daily basis in a 2·5‐year eucalyptus plantation in southeastern Brazil using three sample arrangements: (1) close to tree trunks (CT) and in the central point between trunks (BT), (2) four‐radial layout centred in tree trunk and (3) eight‐radial layout. Throughfall was spatially non‐uniform and varied according to the spatial monitoring arrangement: accumulated throughfall/precipitation ratio of 146% (CT) and 85% (BT) in arrangement 1, mean throughfall of 88% in arrangement 2, 84% (hilltop) and 85% (side slope) in arrangement 3. The highest throughfall values, spatial variability and persistence of dry and wet conditions were found close to eucalyptus trunks. Often accumulated throughfall close to trunks exceeded rainfall, especially for long‐duration rainfall > 5 mm. The ‘funnel effect’ was consistently observed in all three arrangements and we speculate that the high throughfall concentration and temporal stability are related to canopy structures of eucalyptus. Copyright © 2011 John Wiley & Sons, Ltd.
Heat release from rooftops during rainstorms in the Minneapolis/St. Paul Metropolitan Area, USA
Authors: Janke Benjamin D. , Mohseni Omid , Herb William R. , Stefan Heinz G. 
Published: February 2011

AbstractIn the modeling of urban storm water runoff temperatures, the contribution of rooftops to the heating of rainfall runoff is usually neglected or not mentioned in the literature. In this paper we examine the accuracy of this assumption (a) by analyzing temperature data that we recorded on a residential rooftop, a commercial rooftop, and a concrete driveway, and (b) by simulating temperature profiles within rooftops and pavements, and estimating heat transfer amounts from these surfaces to rainfall runoff (‘heat export’). Analysis of both wet‐ and dry‐weather temperature data recorded in the Minneapolis/St. Paul metropolitan area (north‐central USA) over periods of several months leads to the conclusion that (a) a concrete driveway has a far greater capacity for heat storage and release than a shingled residential rooftop, and (b) an insulated commercial rooftop is able to store and release more heat than the residential rooftop. Unexpectedly, the rainfall events with the highest dew point (rainfall) and surface temperatures often occurred during late night or early morning hours, and not during daylight hours. The analysis of three rainfall events showed that the heat export from the commercial rooftop was roughly three times that of the residential rooftop, but only 30%–90% of the heat export from a concrete driveway. Maximum (potential) heat export was significantly higher for the driveway than for either rooftop. In conclusion, the results of the data analysis and heat export simulations support the assumption that residential rooftops contribute very little heating to runoff from rainfall, while commercial rooftops may have a thermal impact on rainfall runoff because of their greater thermal storage capacity. Commercial rooftops, in addition to asphalt and concrete pavements, should be considered when estimating water temperature of rainfall runoff from urbanized areas and the associated impact on the thermal regime of streams and fish habitat. Copyright © 2011 John Wiley & Sons, Ltd.
Quantitative evaluation of different hydrological modelling approaches in a partly glacierized Swiss watershed
Authors: Magnusson Jan , Farinotti Daniel , Jonas Tobias , Bavay Mathias 
Published: February 2011

AbstractMountain water resources management often requires hydrological models that need to handle both snow and ice melt. In this study, we compared two different model types for a partly glacierized watershed in central Switzerland: (1) an energy‐balance model primarily designed for snow simulations; and (2) a temperature‐index model developed for glacier simulations. The models were forced with data extrapolated from long‐term measurement records to mimic the typical input data situation for climate change assessments. By using different methods to distribute precipitation, we also assessed how various snow cover patterns influenced the modelled runoff.The energy‐balance model provided accurate discharge estimations during periods dominated by snow melt, but dropped in performance during the glacier ablation season. The glacier melt rates were sensitive to the modelled snow cover patterns and to the parameterization of turbulent heat fluxes. In contrast, the temperature‐index model poorly reproduced snow melt runoff, but provided accurate discharge estimations during the periods dominated by glacier ablation, almost independently of the method used to distribute precipitation. Apparently, the calibration of this model compensated for the inaccurate precipitation input with biased parameters.Our results show that accurate estimates of snow cover patterns are needed either to correctly constrain the melt parameters of the temperature‐index model or to ensure appropriate glacier surface albedos required by the energy‐balance model. Thus, particularly when only distant meteorological stations are available, carefully selected input data and efficient extrapolation methods of meteorological variables improve the reliability of runoff simulations in high alpine watersheds. Copyright © 2011 John Wiley & Sons, Ltd.
Comparative analysis of rating curve and ADP estimates of instantaneous water discharge through estuaries in two contrasting Brazilian rivers
Authors: da Silva Dias Francisco José , Lacerda Luiz Drude , Marins Rozane Valente , de Paula Francisco Carlos Fernandes 
Published: February 2011

AbstractThis work quantifies, using ADP and rating curve techniques, the instantaneous outflows at estuarine interfaces: higher to middle estuary and middle to lower estuary, in two medium‐sized watersheds (72 000 and 66 000 km2 of area, respectively), the Jaguaribe and Contas Rivers located in the northeastern (semi‐arid) and eastern (tropical humid) Brazilian coasts, respectively. Results from ADP showed that the net water balances show the Contas River as a net water exporter, whereas the Jaguaribe River Estuary is a net water importer. At the Jaguaribe Estuary, water retention during flood tide contributes to 58% of the total volume transferred during the ebb tide from the middle to lower estuary. However, 42% of the total water volume (452 m3 s−1) that entered during flood tide is retained in the middle estuary. In the Contas River, 90% of the total water is retained during the flood tide contributing to the volume transported in the ebb tide from the middle to the lower estuary. Outflows obtained with the rating curve method for the Contas and Jaguaribe Rivers were uniform through time due to river flow normalization by dams in both basins. Estimated outflows with this method are about 65% (Contas) and 95% (Jaguaribe) lower compared to outflows obtained with ADP. This suggests that the outflows obtained with the rating curve method underestimate the net water balance in both systems, particularly in the Jaguaribe River under a semi‐arid climate. This underestimation is somewhat decreased due to wetter conditions in the Contas River basin. Copyright © 2011 John Wiley & Sons, Ltd.
Improvement of snowpack simulations in a regional climate model
Authors: Jin Jiming , Miller Norman L. 
Published: February 2011

AbstractTo improve simulations of regional‐scale snow processes and related cold‐season hydroclimate, the Community Land Model version 3 (CLM3), developed by the National Center for Atmospheric Research (NCAR), was coupled with the Pennsylvania State University/NCAR fifth‐generation Mesoscale Model (MM5). CLM3 physically describes the mass and heat transfer within the snowpack using five snow layers that include liquid water and solid ice. The coupled MM5–CLM3 model performance was evaluated for the snowmelt season in the Columbia River Basin in the Pacific Northwestern United States using gridded temperature and precipitation observations, along with station observations. The results from MM5–CLM3 show a significant improvement in the SWE simulation, which has been underestimated in the original version of MM5 coupled with the Noah land‐surface model. One important cause for the underestimated SWE in Noah is its unrealistic land‐surface structure configuration where vegetation, snow and the topsoil layer are blended when snow is present. This study demonstrates the importance of the sheltering effects of the forest canopy on snow surface energy budgets, which is included in CLM3. Such effects are further seen in the simulations of surface air temperature and precipitation in regional weather and climate models such as MM5. In addition, the snow‐season surface albedo overestimated by MM5–Noah is now more accurately predicted by MM5–CLM3 using a more realistic albedo algorithm that intensifies the solar radiation absorption on the land surface, reducing the strong near‐surface cold bias in MM5–Noah. The cold bias is further alleviated due to a slower snowmelt rate in MM5–CLM3 during the early snowmelt stage, which is closer to observations than the comparable components of MM5–Noah. In addition, the over‐predicted precipitation in the Pacific Northwest as shown in MM5–Noah is significantly decreased in MM5–CLM3 due to the lower evaporation resulting from the longer snow duration. Copyright © 2011 John Wiley & Sons, Ltd.
Measurements of rill and gully erosion in Sicily
Authors: Di Stefano Costanza , Ferro Vito 
Published: February 2011

AbstractThis article reports the results of a field investigation aimed to characterize the morphology of both rills monitored at Sparacia experimental area and two ephemeral gullies (EGs) located in the Tremamargi basin, Sicily, Italy. At first, the available literature data together with the measurements carried out in this investigation were used to show that the EG length is a key parameter for the estimation of the eroded volume. Then, the comparison among the pairs length and volume corresponding to measured rills, EGs and gullies showed that the exponent of the power relationship is independent of the channelized erosion type (rill, EG and gully), while a different scale factor has to be used for each erosion process. Finally, a single relationship applicable to all channelized erosion processes was deduced applying the dimensional analysis and the self‐similarity theory. Copyright © 2011 John Wiley & Sons, Ltd.