A stochastic optimization approach for integrated urban water resource planning

Urban water is facing the challenges of both scarcity and water quality deterioration. Consideration of nonconventional water resources has increasingly become essential over the last decade in urban water resource planning. In addition, rapid urbanization and economic development has led to an increasing uncertain water demand and fragile water infrastructures. Planning of urban water resources is thus in need of not only an integrated consideration of both conventional and nonconventional urban water resources including reclaimed wastewater and harvested rainwater, but also the ability to design under gross future uncertainties for better reliability. This paper developed an integrated nonlinear stochastic optimization model for urban water resource evaluation and planning in order to optimize urban water flows. It accounted for not only water quantity but also water quality from different sources and for different uses with different costs. The model successfully applied to a case study in Beijing, which is facing a significant water shortage. The results reveal how various urban water resources could be cost-effectively allocated by different planning alternatives and how their reliabilities would change.

Aldosterone perturbs adiponectin and PAI-1 expression and secretion in 3T3-L1 adipocytes

Aldosterone is considered as a new cardiovascular risk factor that plays an important role in metabolic syndrome; however, the underlying mechanism of these effects is not clear. Hypoadiponectinemia and elevated circulating concentration of plasminogen activator inhibitor-1 (PAI-1) are causally associated with obesity-related insulin resistance and cardiovascular disease. The aim of the present study is to investigate the effect of aldosterone on the production of adiponectin and PAI-1 in 3T3-L1 adipocytes. Northern and Western blot analyses revealed that aldosterone treatment inhibited adiponectin mRNA expression and secretion and simultaneously enhanced PAI-1 mRNA expression and secretion in a time- and dose-dependent manner. Rosiglitazone did not prevent aldosterone's effect on adiponectin or PAI-1 expression. In contrast, tumor necrosis factor (TNF)-α produced dramatic synergistic effects on adiponectin and PAI-1 expression when added together with aldosterone. Furthermore, the effects of aldosterone on adiponectin and PAI-1 expression appear to be mediated through glucocorticoid receptor (GR) but not mineralocorticoid receptor (MR). These results suggest that the effects of aldosterone on adiponectin and PAI-1 production are one of the underlying mechanisms linking it to insulin resistance, metabolic syndrome and cardiovascular disease.

A reproducible route to p-ZnO films and their application in light-emitting devices

Although great efforts have been made, reproducible p-type doping is still one of the largest hurdles that hinders the optoelectronic applications of ZnO. In this Letter, a reproducible route to p-type ZnO films employing lithium-nitrogen as a dual-acceptor dopant has been demonstrated, and p-i-n structured light-emitting devices (LEDs) have been constructed. Obvious purple emissions have been observed from the LEDs, confirming the applicability of the p-type ZnO films in optoelectronic devices. The results reported in this Letter provide a reproducible route to p-type ZnO films, and thus may lay a solid ground for future optoelectronic applications of ZnO.

The Golden Potato Cyst Nematode Globodera rostochiensis Pathotype Ro1 in the Saint-Amable Regulated Area in Quebec, Canada

The golden potato cyst nematode, Globodera rostochiensis (Wollenweber, 1923) Behren, is an economically important parasite of potato (Solanum tuberosum L. subsp. tuberosum) and is recognized as a quarantine pest internationally (2). This pest attacks potato plants and causes stunting of the haulm and the root system, leaf yellowing, and tuber yield losses (2). The pathotype scheme proposed by Kort et al. distinguishes five pathotypes (Ro1, Ro2, Ro3, Ro4, and Ro5) of G. rostochiensis using differential Solanum clones (1). Several resistance genes and quantitative trait loci (QTL) that have been identified in wild Solanum species confer resistance to different G. rostochiensis pathotypes and have been introgressed into commercial potato cultivars (2). Determining G. rostochiensis pathotype(s) is essential to implement efficient management strategies, which include using resistant potato varieties. G. rostochiensis was discovered in the municipality of Saint-Amable, Quebec (QC), Canada in 2006 (3) and was subsequently characterized (4). In this study, cysts were collected from 11 representative infested fields and confirmed to be G. rostochiensis (3). The pathotypes of these nematodes were assessed on seven differential clones (S. tuberosum subsp. tuberosum cv. Desiree, S. tuberosum × S. andigena cv. Maris Piper, S. kurtzianum hybrid 60.21.19, S. vernei hybrid 62.33.3, S. vernei hybrid 58.1642/4, S. vernei hybrid 65.346/19, and S. multidissectum hybrid P55/7) in 2007 and 2009. Briefly, in each 1-liter plastic pot containing 907 g (2 lbs) of soil (3:1 loam/grit v v-1), a single differential Solanum clone was planted and 15 cysts from 1 of 11 fields were inoculated. Five replicates were set up for each Solanum-nematode combination and the pots were arranged in a completely randomized design in a greenhouse at 22°C with a 16-h light period per day. Nine weeks after inoculation, cysts were extracted from each pot and counted. Reproduction factor (Rf) for each replicate was calculated (Rf = Pf/Pi; Pf is the final cyst number and Pi is the initial cyst number added to each pot). Rf values were used to categorize the differential clones into two groups, "susceptible" leading to increase in nematode numbers (Rf > 1) and "resistant" resulting in decrease in nematode numbers (Rf ≤ 1) (1). Our results in 2007 and 2009 were consistent and the pathotype of the nematodes collected from all the fields were identified as Ro1. To our knowledge, this is the first time that the pathotype of G. rostochiensis in the Saint-Amable regulated area was identified. Accordingly, potato cultivars carrying genes or QTL resistant to G. rostochiensis pathotype Ro1 can be used to reduce the nematode numbers in infested fields in the Saint-Amable area, QC. References: (1) J. Kort et al. Nematologica 23:333, 1977. (2) R. J. Marks and B. B. Brodie. Potato Cyst Nematodes: Biology, Distribution, and Control. 1st ed. CAB International, Wallingford, 1998. (3) F. Sun et al. Plant Dis. 91:908, 2007. (4) Q. Yu et al. Can. J. Plant Pathol. 32:264, 2010.

Estimating nutrient releases from agriculture in China: an extended substance flow analysis framework and a modeling tool

Agriculture related pollution has attracted the attention of policy makers as well as scientists in China as its contribution to water impairment has increased, and quantitative information at the national and regional levels is being sought to support decision making. However, traditional approaches are either time-consuming, expensive (e.g. national surveys) or oversimplified and crude (e.g. coefficient methods). Therefore, this study proposed an extended substance flow analysis (SFA) framework to estimate nutrient releases from agricultural and rural activities in China by depicting the nutrient flows in Chinese agro-ecosystems. The six-step process proposed herein includes: (a) system definition; (b) model development; (c) database development; (d) model validation; (e) results interpretation; and (f) uncertainty analysis. The developed Eubolism (Elementary Unit based nutrient Balance mOdeLIng in agro-ecoSysteM) model combined a nutrient balance module with an emission inventory module to quantify the nutrient flows in the agro-ecosystem. The model was validated and then applied to estimate the total agricultural nutrient loads, identify the contribution of different agricultural and rural activities and different land use types to the total loads, and analyze the spatial pattern of agricultural nutrient emissions in China. These results could provide an entire picture of agricultural pollution at the national level and be used to support policy making. Furthermore, uncertainties associated with the structure of the elementary units, spatial resolution, and inputs/parameters were also analyzed to evaluate the robustness of the model results.

Structure validation of an integrated waterworks model for trihalomethanes simulation by applying regional sensitivity analysis

A previously developed integrated waterworks model for trihalomethanes simulation was validated by applying a new framework for comprehensive model structure validation. The proposed framework followed the procedure of regional sensitivity analysis and also involved correlation analysis and frequency distribution analysis. Through such an analysis framework, a deep insight into model structure and parameters could be gained besides the traditional focuses on model validation, i.e. model performance and rationality of model parameters. The integrated waterworks model, to which the framework was applied, was proved to give good predictions of the simulated variables, and the identified values of model parameters coincided well with the reported values in the literature. The model was also found to have a large proportion of sensitive parameters, no distinct correlations among parameters, and thus a balanced structure. Moreover, most of the sensitive parameters could be well identified and the associated uncertainties significantly reduced. A detailed investigation into the sensitivity, identifiability, and uncertainty of model parameters showed that the model conceptualization was in good agreement with accepted scientific principles and anticipated system behaviors. All these results, therefore, supported the validity and trustworthiness of the model. In addition, further opportunities for refining the model were also proposed.

Environmental neurotoxic pesticide increases histone acetylation to promote apoptosis in dopaminergic neuronal cells: relevance to epigenetic mechanisms of neurodegeneration

Pesticide exposure has been implicated in the etiopathogenesis of Parkinson's disease (PD); in particular, the organochlorine insecticide dieldrin is believed to be associated with PD. Emerging evidence indicates that histone modifications play a critical role in cell death. In this study, we examined the effects of dieldrin treatment on histone acetylation and its role in dieldrin-induced apoptotic cell death in dopaminergic neuronal cells. In mesencephalic dopaminergic neuronal cells, dieldrin induced a time-dependent increase in the acetylation of core histones H3 and H4. Histone acetylation occurred within 10 min of dieldrin exposure indicating that acetylation is an early event in dieldrin neurotoxicity. The hyperacetylation was attributed to dieldrin-induced proteasomal dysfunction, resulting in accumulation of a key histone acetyltransferase (HAT), cAMP response element-binding protein. The novel HAT inhibitor anacardic acid significantly attenuated dieldrin-induced histone acetylation, Protein kinase C delta proteolytic activation and DNA fragmentation in dopaminergic cells protected against dopaminergic neuronal degeneration in primary mesencephalic neuronal cultures. Furthermore, 30-day exposure of dieldrin in mouse models induced histone hyperacetylation in the striatum and substantia nigra. For the first time, our results collectively demonstrate that exposure to the neurotoxic pesticide dieldrin induces acetylation of core histones because of proteasomal dysfunction and that hyperacetylation plays a key role in dopaminergic neuronal degeneration after exposure of dieldrin.