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This study characterized the adaptive attentional allocation that occurs during motor preparation. The specifications of task-relevant and task-irrelevant neural processes are key processes that facilitate successful performances by skilled athletes under difficult task conditions. Previous sport psychophysiology studies have used event-related desynchronization/synchronization analysis and electroencephalography (EEG) power analysis to distinguish the types of neuroelectric activity that occur during effortful but functional performance and effortful but dysfunctional performance. However, the dynamics of cortico-cortical communication in both performance states remain unclear. This study linked the simple model of attention allocation and the psychomotor efficiency hypothesis with EEG coherence analysis to specify the dynamics of cortico-cortical communication during successful performance. A within-subjects design was used. Intersite phase coherence (ISPC) and imaginary ISPC were used to compute 8-13 Hz EEG connectivity from EEG recordings obtained before successful and unsuccessful performances (i.e., 40 skilled golfers; 40%-60% putting success rate as individual task difficulty). Successful performance was characterized by (a) lower 8-13 Hz ISPC and imaginary ISPC (imISPC) at T7-Fz in the -2,000 to -1,000 ms time window and (b) lower 8-13 Hz imISPC at T7-Cz in the -1,000 to 0 ms time window. This study suggests that successful performance is characterized by reduced communication between verbal-analytical and motor planning processes, followed by decreased communication between verbal-analytical and motor control processes before putting initiation. Our findings not only characterize the dynamic neuromotor processes between successful performance and unsuccessful performance of a difficult task, but also provide practical guidelines for interventions such as neurofeedback training.

Once the pollution was found in a preliminary survey, the related information about the pollution site should be collected to confirm polluted range and quantity. Appropriate remediation technology is implemented until the pollution is completely remove. The more precise survey could lower the risk of uncertainty and improve the site remediation process. However, numerous of sampling and analysis should be done during whole process, including pollution survey, evaluation of remediation effectiveness, and verification after remediation. Time and budget needed for the remediation will be huge loads because of the widely range of site, and characteristics of the complicated pollutants, which may affect the remediation process. This study utilities Enzyme-Linked ImmunoSorbant Assay (ELISA) as the screening tool for dioxin pollutants by means of immuno-biological assay, which can complete the detailed investigation quickly and effectively, and also the pollution reclamation in a short time with the independent quality control. An appropriate screening method plays an important role for a successful and effective remediation.

The removal of tetracycline (TC) from aqueous environment by illite (IMt-2) was studied in a batch system at different pH and ionic strength conditions. Adsorbent characterizations were determined by XRD and FTIR. The TC adsorption capacity on IMt-2 was 32 mg/g at pH 5–6 and the adsorption equilibrium data obeyed the Freundlich isotherm. The kinetics of TC adsorption was moderately fast and almost reached equilibrium in 8 h and the results followed pseudo-second-order kinetic model and Elovich model. The X-ray diffraction patterns before and after TC adsorption revealed no changes in basal spacing and intensity under two kinetic adsorption and a few initial TC concentration conditions, indicating that the adsorbed TC molecules were on the external surface of the mineral in contrast to intercalation of TC into swelling clay minerals, such as montmorillonite and rectorite. In spite of its low TC adsorption capacity, the results suggested that IMt-2 could be a good candidate to remove TC from wastewater containing higher amounts of TC and illite would be an important environmental sink for the fate and transport of TC in soils.

The synthesis and fractioning of nanoparticles by pneumatic foam fractionation, using NiO as a demonstration is presented. The foam was allowed to travel to different vertical column heights and was then fractionated. The nickel ions in the cetyltrimethylammonium bromide (CTAB) foam reacts with ammonia vapor to precipitate Ni(OH)2, and the capillary formed within the bubbles provided a unique microenvironment for the formation of nanoparticles. During the travel of the foam, the concentration of CTAB does not remain constant at different column heights, i.e., liquid near an interface with a gaseous phase has a different composition to that of the bulk liquid. Thus the height of the foam column affects the degree of enrichment of the foamate. Various morphologies of Ni(OH)2 were obtained, such as petal/coralloid and thin flake-like structures, owing to the concentration gradient across the column height of the fractions. On thermal decomposition, Ni(OH)2 produced NiO of various morphologies, such as a lotus root-like structure and flat angular plate-like structures. These NiO nanoparticles of different fractions have different BET surface areas and magnetic properties. Our experiments demonstrate that in a single batch one can control and separate the crystal structures with different physical properties using fractionation with various column heights.

Swelling clays have been extensively studied to remove contaminants from aqueous solution. This research aimed at elucidating the mechanism of adsorption of acridine orange (AO), a cationic dye, on low charge montmorillonite in order to better understand the principles behind AO removal using swelling clays. Proportional desorption of exchangeable cations from the clays accompanying AO adsorption confirmed cation exchange as the most dominant mechanism for AO removal. FTIR analyses further confirmed the presence of cationic dye AOH + on the surface and in the interlayer of the swelling clays. XRD and TG-DTG analyses revealed interlayer adsorption, thus, intercalation of AO molecules with different conformations at low and higher AO adsorption levels. Molecular simulation showed dimer and horizontal bilayer formation of intercalated AO at the low and high adsorption levels. At the intermediate AO adsorption levels, the dimer intercalated and bilayer intercalated swelling clays formed mixtures at the single crystal scale, resulting in a significant broadening of (0 0 1) peak. The results showed that the uptake of AO could far exceed the cation exchange capacity, an advantage of using swelling clays to treat wastewater containing cationic dyes.

Fluid and mud samples were collected from Wushanting (WST), Hsiaokunshui (HKS), Yenshuikeng (YSK), Kuantzeling (KZL), and Kunshuiping (KSP) mud volcanoes of southwestern Taiwan. Concentrations of major ions and trace elements in mud volcanic fluids were analyzed to find the possible linkage to elevated arsenic (As) concentrations in the Chianan plain groundwater. The elevated Na+, K+, and Cl− concentrations indicated possible marine origin of the fluids. The trace element concentrations in the mud volcanic fluids were generally low, but the As concentrations were up to 0.12 mg/L. High contents of As, Fe, and Mn were observed in the mud samples. Saturation index calculations indicated that both carbonate and oxide minerals acted as potential sinks for As in the mud volcanic fluids. Arsenic in the dewatering fluids and muds may be transported by the subsurface flow and surface streams as suspended solids and eventually deposited in the Chianan plain aquifers. Under reducing conditions, As may be released from the host minerals (such as Fe- and Mn-oxides/hydroxides), thereby causing widespread groundwater As pollution.

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in sediment and fish of aqua farms close to a contaminated site of a pentachlorophenol production plant (CPDC-ASS) were investigated. The total PCDD/F I-TEQ level in sediment and fish ranged from 0.725 to 87.9 ng I-TEQ kg(-1)d.w.(-1) and 0.044 to 3.10 pg I-TEQ g(-1)w.w.(-1), respectively, meaning that the CPDC-ASS was a long-term exposure PCDD/F contaminated area. The four dominant congeners in sediment and fish were OCDD, OCDF, 1,2,3,4,6,7,8-HpCDF and 1,2,3,4,6,7,8-HpCDD. The correlated coefficient of total I-TEQ PCDD/F contents between fish and sediment was 0.82 (R(2)), indicating a positive correlation between exposure to PCDD/Fs in sediment and biota. In addition, the biota-to-sediment accumulation factors (BSAFs) values of low chlorinated PCDD/F congeners such as those of 2,3,7,8-TeCDD for Milkfish and Tilapia were 0.00739 and 0.00593, respectively, which were much higher than those of highly chlorinated congeners. For example, the BSAFs of OCDD for Milkfish and Tilapia were 0.000207 and 0.000277, respectively. A negative relationship of log K(ow) and log BSAF for PCDD/F congeners was found, and the highest value was observed at approximately K(ow)= 7.0-7.5. The results of this study provide valuable information for establishing the PCDD/F regulated standard for the sediment of fish ponds.

This work characterized the sink and source/mobility of As in the As-affected sedimentary aquifers of the southern Choushui River alluvial fan, central Taiwan. Major mineral phases and chemical components were determined by XRD and X-ray photoelectron spectroscopy (XPS). The partitioning of As and Fe among cores were determined by sequential extraction. Based on XPS results, the primary forms of Fe were hematite, goethite and magnetite. Sequential extraction data and the XRF analysis indicated that Fe oxyhydroxides and sulfides were likely to be the major sinks of As, particularly in the distal-fan. Furthermore, Fe oxyhydroxides retained higher As contents than As-bearing sulfides. The reductive dissolution of Fe oxyhydroxides, which accompanied high levels of HCO 3 - and NH 4 + concentrations, was likely the principal release mechanism of As into groundwater in this area. The dual roles of Fe oxyhydroxides which are governed by the local redox condition act as a sink and source in the aquifer. Ionic replacement by PO 4 3 - and HCO 3 - along with seasonal water table fluctuation, caused by monsoons and excessive pumping, contributed specific parts of As in the groundwater. The findings can be used to account for the inconsistency between Fe and As concentrations observed in groundwater.

Oxidation of cyclohexene using aqueous hydrogen peroxide (30%, v/v) over iron–cerium oxide ( x %Fe/CeO 2 ; x = 0, 2, 5, 10 and 20 mol%) prepared by co-precipitation was conducted in this study in order to assess the performance of the catalysts of varying composition, and catalytic activity and product selectivity were found to strongly depend on catalyst composition, acidity and reducibility. The effects of varying the catalyst composition, reaction temperature and solvent were investigated. Cyclohexene epoxide and 1,2-cyclohexanediol were found to be the main reaction products, along with small amounts of other oxygenated products. A high cyclohexene conversion rate of 99 mol% and an epoxide selectivity of 98 mol% were observed over 5%Fe/CeO 2 at 100 °C. The catalysts were characterized using various techniques and measures, including BET surface area, XRD, DRS UV–vis, potentiometric titration for acidity measurement, and XPS. XRD showed the formation of iron–cerium oxide solid solutions with cerianite cubic structures for all catalysts except FC4, and the DRS UV–vis results further indicated the formation of solid solutions. Analysis of Raman spectra revealed the presence of aggregate iron oxide species in case of 20%Fe/CeO 2 catalyst. TPR revealed enhancement of the reducibility of the ceria upon Fe doping, and the potentiometric titration results showed an increase in the number of acidic sites with increasing iron content up to 5% and a decrease thereafter. TPR and XPS analyses revealed the presence of highly dispersed Fe species in the 2%Fe/CeO 2 and 5%Fe/CeO 2 samples, whereas for the 10%Fe/CeO 2 and 20%Fe/CeO 2 catalysts, aggregates of Fe species were observed. Catalytic activity was found to be correlated with the composition and acidic properties of the catalyst.

Mud volcanoes distributed in the southern part of Taiwan are believed to be sourced from an accretionary prism located along the collision boundary between the Philippine Sea plate and the Asian Continental plate. Fluid and mud samples have been collected from Wushanting and Hsiaokunshui mud volcanoes during October 2004, March and June 2005, and analyzed for major ions, trace elements, and stable isotopes. The results show that the mud volcano fluids are enriched in Na + and Cl − but are depleted in Ca 2+ and Mg 2+ . The chemical composition and oxidation state of the fluids fluctuate seasonally, with ionic contents being notably higher during the dry pre-monsoon period. The enriched ionic (e.g., Na + , NH 4 + , K + , Mg 2+ and Cl − ) compositions of the exchangeable fractions indicate that the muds were sourced from a marine depositional environment. δD and δ 18 O values indicate that the mud volcano fluids may have been modified by chemical exchange with 18 O-rich crustal rocks and possibly originated from mixing of deep brines with circulating meteoric water. The spatial and temporal distribution of ions in the muds suggests a varied mixing regime within the mud volcanoes. Incubation study of the muds shows the leaching of soluble salts under aerobic conditions, which is generally consistent with the fluid geochemical characteristics. Moreover, elevated trace element (e.g., As, Zn, Cu and Mn) concentrations are also observed in the fluids and muds. Geochemical correlations between As, Zn and Cu in the muds suggest prevailing SO 4 -reducing conditions at depth. The relatively low Eh values (range: −50 to −30 mV) of the fluids near the surface would favor bacterial Fe reduction and mobilization of As. The dewatering of mud volcanoes may represent a significant source of groundwater As in the nearby Chianan plain.

Extensive use of pharmaceuticals and growth hormone in farm animal and live stocks has resulted in their frequent detection in soils, groundwater, and wastewater. The fate and transport of these compounds are strongly affected by their sorptive behavior to the soil minerals and humic materials. In this research, we conducted the sorption of tetracycline (TC), a common antibiotic, on palygorskite (PFL-1), a fibrous clay mineral of high surface area and high sorptivity towards organic compounds. The results showed that the sorption capacity of TC on PFL-1 was as high as 210 mmol/kg at pH 8.7. The sorption was relatively fast and reached equilibrium in 2h. Solution pH and ionic strength had significant effects on TC sorption. The sorption of TC by palygorskite is endothermic and the free energy of sorption is in the range of -10 to -30 kJ/mol, suggesting a strong physical sorption. The X-ray diffraction patterns before and after TC sorption revealed no changes in d-spacing and intensity under different pH and initial TC concentrations, indicating that the sorbed TC molecules are on the external surface of the mineral in contrast to intercalation of TC into swelling clays, such as montmorillonite. The small positive value of entropy change suggested that TC molecules are in disordered arrangement on palygorskite surfaces. Surface sorption of TC on PFL-1 is further supported by the derivative of gravimetric analysis and by the calculation of the amount of TC sorption normalized to the surface area. The results suggest that palygorskite could be a good candidate to remove TC from wastewater containing higher amounts of TC.

This work explored a risk-based arsenic (As) regulation in farmed pond water by ingesting tilapia (Oreochromis mossambicus) in blackfoot disease hyper- endemic areas and discussed a rational As regulation in pond water. Monte Carlo analysis was used to propagate the parameter uncertainty and to assess probabilistically regulation risks. A dynamic scheme of groundwater man- agement was proposed that curves of utilization ratios against As concentrations in groundwater were established based on the risk-based regulation. The 5th to 95th per- centiles of risks range from 3.5 9 10 -7 to 6.0 9 10 -5 via ingesting the farmed tilapia under the current As regulation in farmed pond water in Taiwan, 50 lg/L. To compare to inorganic As regulation in drinking water, the current As regulation in farmed pond water does not pose a great threat to human health, but it is unsafe. Therefore, this study suggests that the regulation of As in farmed pond water is revised to be 25 lg/L.

The back-propagation (BP) artificial neural network (ANN) is applied to forecast the variation of the quality of groundwater in the blackfoot disease area in Taiwan. Three types of BP ANN models were established to evaluate their learning performance. Model A included five concentration parameters as input variables for seawater intrusion and three concentration parameters as input variables for arsenic pollutant, respectively, whereas models B and C used only one concentration parameter for each. Furthermore, model C used seasonal data from two seasons to train the ANN, whereas models A and C used only data from one season. The results indicate that model C outperforms models A and B. Model C can describe complex variation of groundwater quality and be used to perform reliable forecasting. Moreover, the number of hidden nodes does not significantly influence the performance of the ANN model in training or testing.

Factor analysis is applied to 28 groundwater samples collected from wells in the coastal blackfoot disease area of Yun-Lin, Taiwan. Correlations among 13 hydrochemical parameters are statistically examined. A two-factor model is suggested and explains over 77.8% of the total groundwater quality variation. Factor 1 (seawater salinization) includes concentrations of EC, TDS, Cl(-), SO(4)(2-), Na(+), K(+) and Mg(2+), and Factor 2 (arsenic pollutant) includes concentrations of Alk, TOC and arsenic. Maps are drawn to show the geographical distribution of the factors. These maps delineate high salinity and arsenic concentrations. The geographical distribution of the factor scores at individual wells does not reveal the sources of the constituents, which are instead, deduced from geological and hydrological evidence. The areas of high seawater salinization and arsenic pollution correspond well to the groundwater over-pumping area. Over-pumping of the local groundwater causes land subsidence and gradual salinization by seawater. The over-pumping also introduces excess dissolved oxygen that oxidizes the immobile minerals, releases arsenic by reductive dissolution of arsenic-rich iron oxyhydroxides and increases the arsenic concentration in water. The over-extraction of groundwater is the major cause of groundwater salinization and arsenic pollution in the coastal area of Yun-Lin, Taiwan.

Blackfoot disease (BFD) had occurred seriously in the Yichu, Hsuehchia, Putai, and Peimen townships of Chia-Nan District of Taiwan in the early days. These four townships are the districts of fishpond cultivation domestically in Taiwan. Groundwater becomes the main water supply because of short income in surface water. The problems of over pumping in groundwater may not only result in land subsidence and seawater intrusion but also be harmful to the health of human giving rise to the bioaccumulation via food chain in groundwater with arsenic (As). This research uses sequential indicator simulation (SIS) to characterize the spatial arsenic distribution in groundwater in the four townships. Risk assessment is applied to explore the dilution ratio (DR) of groundwater utilization, which is defined as the ratio showing the volume of groundwater utilization compared to pond water, for fish farming in the range of target cancer risk (TR) especially on the magnitude of 10(-4)~10(-6). Our study results reveal that the 50th percentile of groundwater DRs served as a regulation standard can be used to perform fish farm groundwater management for a TR of 10(-6). For a TR of 5 × 10(-6), we suggest using the 75th percentile of DR for groundwater management. For a TR of 10(-5), we suggest using the 95th percentile of the DR standard for performing groundwater management in fish farm areas. For the TR of exceeding 5 × 10(-5), we do not suggest establishing groundwater management standards under these risk standards. Based on the research results, we suggest that establishing a TR at 10(-5) and using the 95th percentile of DR are best for groundwater management in fish farm areas.

Redox couples approach and multivariate statistical techniques, including factor analysis, cluster analysis and discriminant analysis, were applied to evaluate and to interpret the complex groundwater quality in the blackfoot disease endemic area, Taiwan. Most groundwater samples were characterized as Na-Ca-HCO(3) with HCO(3)(-) as the dominant anion. Total arsenic (As) concentration, predominantly as As(3+), ranged from1.0 to 562.7 μg/L. The patterns of measured reducing potential were consistent with those values calculated from As couple, revealing the in situ environment enhanced the accumulation of As concentration in the groundwater. Factor analysis proposed a four-factor model, comprising salination, reductive dissolution of Fe/Mn oxyhydroxides, As reduction and chemical potential factor, and explained 89.94% of total variance in groundwater. Furthermore, two factors, reductive dissolution of Fe/Mn oxyhydroxides and As reduction, suggested that the decoupled reductive processes accounted for high As concentration in this area. Cluster analysis was adopted to spatially categorize the sampled wells into three main clusters and characterized by the factor scores of the four-factor model. Two-parameter (pH and Eh) model derived from discriminant analysis can be used for preliminary assessment to determine whether the As concentration exceeds 10 μg/L with simple field measurements in this area.

This study presented an integrated GIS-based approach for assessing potential carcinogenic risks via food-chain exposure of ingesting inorganic arsenic (As) in aquacultural tilapia, milkfish, mullet, and clam in the As-affected groundwater areas. To integrate spatial information, geographic information system (GIS) was adopted to combine polygon-shaped features of aquacultural species with cell-shaped features of As contamination in groundwater. Owing to sparse measured data, Monte Carlo simulation and sequential indicator simulation were used to characterize the uncertainty of assessed parameters. Target cancer risks (TRs) of ingesting As contents at fish ponds were spatially mapped to assess potential risks to human health. The analyzed results reveal that clam farmed at the western coastal ponds and milkfish farmed at the southwestern coastal ponds have high risks to human health, whereas tilapia cultivated mainly at the inland ponds only has high risks at the 95th percentile of TR. Mullet in general has low risks to human health. Moreover, to decrease risks, this study suggests reducing the use of As-affected groundwater at clam and milkfish ponds due to high bioconcentration factor (BCF) of clam and inorganic As accumulation ratio of milkfish. The integrated GIS-based approach can provide fishery administrators with an effective management strategy at specific fish ponds with high risks to human health.

This study surveyed the total arsenic (As) and As species contents in clams (Meretrix lusoria) farmed in areas of hyperendemic blackfoot disease (BFD) in southwestern Taiwan. Total As and As species in sediment and pond water were also analyzed to examine the bioaccumulation of As in clams in their exposure environment. Moreover, potential carcinogenic risks associated with the ingestion of As in aquacultural clams were evaluated probabilistically. The average total As contents in medium-sized and small clams were 7.62 and 10.71 microg/g (dry wt), respectively. The content of the As species in this study was approximately 61% of the total As content. The other unquantified As species are possibly arsenocholine, arsenosugar and arsenolipid. The average ratios of inorganic As contents to total As contents in clams ranged from 12.3% to 14.0% which are much higher than that found in the farmed oyster (Crassostrea gigas), indicating that humans may expose to larger quantities of inorganic As by ingesting the same amount of clam as oyster. Using different ingestion rates derived by the average consumption method and the questionnaire method, the estimated risks to human health associated with consuming clams from the BFD area ranging from slightly to largely exceed the standard target risk. Based on the estimation of the TR model, a 0.18g/day-person of the safe ingestion rate of clams in the BFD region is recommended.

This work analyzed spatially potential carcinogenic risks associated with ingesting arsenic (As) contents in aquacultural tilapia (Oreochromis mossambicus) in coastal regions of southwestern Taiwan, where the blackfoot disease prevails. Sequential indicator simulation (SIS) was used to reproduce As exposure distributions in groundwater based on their three-dimensional variability. A target cancer risk (TR) associated with ingesting As in aquacultural tilapia was calculated to evaluate the potential risk to human health. Owing to sparse measured data, Monte Carlo simulation and SIS properly accounted for the uncertainty of assessed parameters. The probabilistic risk assessment formulated suitable strategies under various remedial stages. Aquacultural regions with high risks were mapped to elucidate the safety of groundwater use at different depths. Many TRs determined from the risks at the 75th and 95th percentiles exceed one millionth in the regions, indicating that ingesting tilapia farmed in the highly As-polluted regions poses potential cancer threats to human health. The 75th percentile of TR is considered in formulating a remedial strategy for the aquacultural use of groundwater in the preliminary stage. Additionally, this study suggests reducing the use of groundwater in aquaculture or changing the depths from which groundwater is withdrawn in the areas with high risks of cancer.

A study was conducted to measure the arsenic species in farmed mouthbreeder (Oreochromis mossambicus) and culture ponds in water in blackfoot disease (BFD) hyperendemic areas in Taiwan. The relationships between arsenic species of aquaculture ponds and farmed fish were also explored. Biota samples were extracted with methanol/water (1/1, v/v) using a Soxhlet extraction apparatus. The concentrations of arsenite As (III), arsenate As (V), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) of extracts were measured by high-performance liquid chromatography (HPLC) linked to a hydride generator and atomic absorption spectrometry (HG-AAS). Moreover, arsenobetaine (AB) was analyzed by HPLClinked to ultra violet (UV) and HG-AAS. Concentrations of arsenic species were determined in 68 mouthbreeder (O. mossambicus) samples and 21 culture ponds from Putai and Yichu Townships of Chiayi County and Hsuehchia and Peimen Townships of Tainan County. The mean arsenic levels of culture ponds in Putai, Yichu, Hsuehchia, and Peimen were 75.8, 15.1, 14.4, and 221.0 mg/l, respectively. The water of culture ponds was dominated by As (V). The inorganic arsenic percentage of fish (7.4%) was higher than that reported by other seafood surveys. Except for the MMA and As (III) levels, As (V), DMA, AB, and total arsenic levels in fish significantly increased with inorganic and total arsenic concentrations of the pond water. Inorganic arsenic species are more toxic than methyl arsenic species. Therefore the effect of inorganic arsenic species might result in a greater number of adverse health effects to the general public. It is of importance to evaluate the inorganic arsenic levels of farmed seafood in arsenic-contaminated areas. # 2003 Elsevier Ltd. All rights reserved.