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The sediment accumulation is an important characteristic in the ageing process of integrated constructed wetlands (ICW). Retained nutrient and other contaminants in wetland sediments have the potential to be remobilized and released to the overlying water column when environmental conditions change. In this study, mesocosms which filled with saturated sediments and planted with Phragmites australis and Agrostis stolonifera were set up to examine nutrient and other contaminants retention and/or release by wetland sediment and substrates. The effects of physico-chemical parameters on sediment-water contaminant exchange were also investigated through the application of multiple regression models, principal component analysis (PCA), redundancy analysis (RDA), and self-organizing map (SOM) model. The results demonstrated an average net release of chemical oxygen demand (COD), ammonianitrogen (NH3-N), nitrate-nitrogen (NO3-N) and molybdate reactive phosphorus (MRP) to the overlying water column, indicating that the ICW sediment and substrates acted as new contaminant sources. According to statistical analysis, electrical conductivity (EC) and redox potential (RP) values affected COD treatment efficiency. Chloride (Cl) concentration and RP value had an impact on NH3-N treatment performance. NO3-N removal was influenced by dissolved oxygen (DO) concentration and RP value. MRP treatment efficiency was related to DO concentration and EC value. The SOM model was selected as prediction tool to provide numerical estimations for the performance of ICW mesocosms. The model was validated, indicating that NH3-N, NO3-N, MRP, and COD treatment efficiencies could be predicted by input variables which are quick and cost-effective to measure. The SOM model can be seen as an appropriate method for monitoring the performance of mature ICWs. The type of vegetation played a minor role in releasing nutrients and other contaminants. However, the mesocosm planted with Phragmites australis outperformed the one planted with Agrostis stolonifera. No water reached bottom outlet of the mesocosm suggesting that there was little potential risk to contaminate groundwater. The clay liner and the biogeochemical processes taking place within sediments proved to be effective in preventing surface water from infiltration. Although no reduction in the overall performance has been observed for the full-scale ICW sites 7 and/or 11, this laboratory-scale study provided valuable warning signs regarding the loss of contaminant sequestration which may contribute to decline in wetland treatment performance over time. The impacts of hydraulic loading rate (HLR) and seasonal temperature fluctuations on contaminant removal efficiencies of a new ICW system receiving domestic wastewater were also assessed. The system showed good overall treatment performance in terms of effluent quality and removal efficiency. The influence of ICW removal efficiencies of the hydraulic loading rate, which was based on overall water balance, was negligible due to large footprint and multi-cellular configuration of the studied system. Relatively low temperature in autumns and winters resulted in decreased biological activities and lower contaminant removal efficiency. The long-term trends in nutrient removal have been investigated to five Wildfowl & Wetlands Trust constructed wetland systems. The results showed less effective removal even release of NO3-N, total oxidised nitrogen (TON), orthophosphate- phosphorus (PO4-P) and total phosphorus (TP) in many of the systems as a result of wetland aging and lack of sediment management.

This study initially evaluated the alteration of CaMKII autophosphorylation and subcellular distribution in rat brain following a single, brief PTZ seizure. Total CaMKII á subunit and á-CaMKII phosphorylated at Thr286 were detected by immunoblot. A large decrease in CaMKII Thr286 phosphorylation, as well as CaMKII translocation from particulate to soluble fraction was evidenced in both cerebral cortex and hippocampus 0.5-4 h after the brief PTZ convulsion. These changes reverted to control values by 12 h. These long-lasting change in CaMKII autophosphorylation and subcellular distribution after a brief seizure suggested that CaMKII could be involved in carrying forward the signal resulting from the insult generated by brief seizure activity, at least for a few hours, as would be required for kindling to occur. Thus, PTZ kindling was performed, and changes in CaMKII were measured during and immediately after the completion of kindling. In PTZ kindled rats, convulsions produced changes in CaMKII Thr286 phosphorylation and distribution in the same direction and of similar magnitude as after the acute convulsion, but lasting for a much longer time. In fact, reduced Thr286 phosphorylation of á-CaMKII was observed up to 48 h, completely bridging the interval between PTZ injections. Similar, but intermediate changes were found in tissue from rats that were only partially kindled. These results implicate CaMKII as a molecular messenger in the acquisition of PTZ kindling. To answer the question of what mechanism maintains the prolonged reduction in CaMKII autophosphorylation, a brief PTZ-induce seizure was used to test the hypothesis of phosphatase activation. It was found that the reduced CaMKII Thr286 phosphorylation apparently resulted from enhanced phosphatase activity, especially in the particulate 144 fraction. Simultaneously, CaMKII translocated from particulate toward soluble fraction. Thus, CaMKII translocation and phosphatase activation might act synergistically in longlasting CaMKII regulation far outlasting the immediate effects of the seizure on neuronal function. It is then hypothesized that enhanced phosphatase activity might also be involved in modulating CaMKII autophosphorylation during PTZ kindling process. In addition, CaMKII translocation found during PTZ kindling might also play some significant role in the CaMKII-phosphatase interaction during PTZ kindling.