Gambogic acid suppresses nasopharyngeal carcinoma via rewiring molecular network of cancer malignancy and immunosurveillance.

Nasopharyngeal carcinoma (NPC) is a malignant tumor highly prevalent in Southeast Asia. The distant metastasis and disease recurrence are still unsolved clinical problems. In recent years, traditional Chinese medicine (TCM) monomers have become significantly attractive due to their advantages. Using high throughput drug sensitivity screening, we identified gambogic acid (GA) as a common TCM monomer displaying multiple anti-NPC effects. GA could effectively inhibit the proliferation of low differentiated cells and highly metastatic cells in NPC via inducing apoptosis and G2/M cell cycle arrest. In addition, GA obviously repressed the abilities of cell clone, migration, invasion, angiogenesis and represented satisfied synergistic effects combined with chemotherapy. Importantly, we found the elevated immune checkpoint CD47 stimulated after chemotherapy was dramatically impaired by GA treatment. Mechanically, the network pharmacology analyses unraveled that the oncogenic signaling pathways including STATs were rewired by GA treatment. Taken together, our study reveals a molecular basis and provides a rationale for GA application as the treatment regime in NPC therapy in future.

[Effects of Fertilization on the Nitrogen Residual Amounts and Leaching from Citrus Orchard Soil in the Three Gorges Reservoir Area].

This experiment has the citrus orchard soil in the basin of the Zigui County Ecological Station in the Three Gorges Reservoir Area as its research object. Leaching tests of an undisturbed soil column at 0-20, 0-40, and 0-60 cm depth were performed in a citrus orchard. The effects of nitrogen leaching and residual amounts in the soil were studied. Four kinds of fertilization treatments were set up in the experiment:no fertilization treatment (CK), low nitrogen fertilization treatment (T1:250kg·hm-2), medium nitrogen fertilization treatment (T2:500kg·hm-2), and high nitrogen fertilization treatment (T3:750kg·hm-2). The results showed that:① The main form of nitrogen leaching in citrus orchard soil was nitrate nitrogen (NO3--N), accounting for 36.93%-60.07% of total nitrogen (TN) leaching. The ratio of TN to ammonium nitrogen (NH4+-N) was 4.40% to 5.79%. The ratio of NO3--N residues in soil to TN residues was 11.31‰-45.66‰, and the ratio of NH4+-N residues to TN residues was 1.051‰-2.07‰. ② Nitrogen leaching and residual amounts in citrus orchards at the same depth showed significant positive correlation with the amount of fertilizer applied. The leaching losses and residual amounts of TN in soil at different fertilization rates were 11.35-30.11 kg·hm-2and 0.30-1.86 g·kg-1, respectively. Among them, the ratio of leaching losses of NO3--N and NH4+-N to TN leaching amounts peaked under T2 treatment, and the peaks of NO3--N and NH4+-N residues in TN residual amounts appeared in T1 and T2 treatment, respectively. ③ Given the same fertilization amounts, the leaching amounts and residual amounts of different forms of nitrogen in the soil were greatly affected by soil depth. After fertilization, the peaks of NO3--N leaching and residual amounts appeared at 20 cm and 40 cm, respectively, and the peaks of NH4+-N leaching and residual amounts mainly appeared at 20 cm depth. Inferred from the results of the experiment, the neutral nitrogen treatment in the 0-40 cm soil column is more conducive to the conversion of fertilizer nitrogen to inorganic nitrogen for plant absorption, and reduces the risk of nitrogen leaching after fertilization.

Physiological clearance of tau in the periphery and its therapeutic potential for tauopathies.

Accumulation of pathological tau is the hallmark of Alzheimer's disease and other tauopathies and is closely correlated with cognitive decline. Clearance of pathological tau from the brain is a major therapeutic strategy for tauopathies. The physiological capacity of the periphery to clear brain-derived tau and its therapeutic potential remain largely unknown. Here, we found that cisterna magna injected 131I-labelled synthetic tau dynamically effluxed from the brain and was mainly cleared from the kidney, blood, and liver in mice; we also found that plasma tau levels in inferior vena cava were lower than those in femoral artery in humans. These findings suggest that tau proteins can efflux out of the brain and be cleared in the periphery under physiological conditions. Next, we showed that lowering blood tau levels via peritoneal dialysis could reduce interstitial fluid (ISF) tau levels in the brain, and tau levels in the blood and ISF were dynamically correlated; furthermore, tau efflux from the brain was accelerated after the addition of another set of peripheral system in a parabiosis model. Finally, we established parabiosis mouse models using tau transgenic mice and their wild-type littermates and found that brain tau levels and related pathologies in parabiotic transgenic mice were significantly reduced after parabiosis, suggesting that chronic enhancement of peripheral tau clearance alleviates pathological tau accumulation and neurodegeneration in the brain. Our study provides the first evidence of physiological clearance of brain-derived pathological tau in the periphery, suggesting that enhancing peripheral tau clearance is a potential therapeutic strategy for tauopathies.

[Characteristics of Nitrogen and Phosphorus Output in Runoff and Rainfall Runoff in Lanlingxi Watershed, Three Gorges Reservoir Area].

The small watershed of an agroforestry system in the Lanlingxi watershed in the Three Gorges Reservoir area was studied by performing continuous monitoring of nitrogen and phosphorus output and concentrations and analyzing the changes in the output of nitrogen and phosphorus in runoff and its response to different rainfall conditions. The results showed that:①The total runoff loss was 50.92×104 m3 in this watershed during the rainy season, with 52.43 kg·hm-2 lost by total nitrogen, including nitrate nitrogen (30.26 kg·hm-2) and particulate nitrogen (21.61 kg·hm-2), and 0.06 kg·hm-2 and 0.10 kg·hm-2 lost by ammonium nitrogen and total phosphorus; ②The distribution of rainfall has the characteristics of stage and strong rainfall during the wet season was the main driving force of soil nutrient output. Rainfall runoff contributed to 88% of total nitrogen loss and 90% of total phosphorus loss in the rainy season; ③The main path of nitrogen and phosphorus loss in the rainy season was the surface runoff caused by rainfall, accounting for 68% of total nitrogen loss and 74% of total phosphorus loss; ④Nitrate nitrogen concentrations showed a negative correlation with rainfall runoff and the output was mainly distributed in the later runoff process. Ammonium nitrogen and total phosphorus concentrations were positively correlated with rainfall and both were mainly distributed in the early stage of the runoff process; ⑤The concentrations of total nitrogen in this watershed exceeded the standard values. The water quality in the rainfall and the non-rainfall period was worse than Grade Ⅴ.

iTRAQ-Based Proteomics Suggests Ephb6 as a Potential Regulator of the ERK Pathway in the Prefrontal Cortex of Chronic Social Defeat Stress Model Mice.

PURPOSE: Major depressive disorder (MDD) is a worldwide concern and devastating psychiatric disease. The World Health Organization claims that MDD leads to at least 11.9% of the global burden of disease. However, the underlying pathophysiology mechanisms of MDD remain largely unknown. EXPERIMENTAL DESIGN: Herein, we proteomic-based strategy is used to compare the prefrontal cortex (PFC) in chronic social defeat stress (CSDS) model mice with a control group. Based on pooled samples, differential proteins are identified in the PFC proteome using iTRAQ coupled with LC-MS/MS. RESULTS: Ingenuity Pathway Analysis (IPA) is then followed to predict relevant pathways, with the ephrin receptor signaling pathway selected for further research. Additionally, as the selected key proteins of the ephrin receptor signaling pathway, ephrin type-B receptor 6 (EphB6) and the ERK pathway are validated by Western blotting. CONCLUSION AND CLINICAL RELEVANT: Altogether, increased understanding of the ephrin receptor signaling pathway in MDD is provided, which implicates further investigation of PFC dysfunction induced by CSDS treatment.

Peritoneal dialysis reduces amyloid-beta plasma levels in humans and attenuates Alzheimer-associated phenotypes in an APP/PS1 mouse model.

Clearance of amyloid-beta (Aß) from the brain is an important therapeutic strategy for Alzheimer's disease (AD). Current studies mainly focus on the central approach of Aß clearance by introducing therapeutic agents into the brain. In a previous study, we found that peripheral tissues and organs play important roles in clearing brain-derived Aß, suggesting that the peripheral approach of removing Aß from the blood may also be effective for AD therapy. Here, we investigated whether peritoneal dialysis, a clinically available therapeutic method for chronic kidney disease (CKD), reduces brain Aß burden and attenuates AD-type pathologies and cognitive impairments. Thirty patients with newly diagnosed CKD were enrolled. The plasma Aß concentrations of the patients were measured before and after peritoneal dialysis. APP/PS1 mice were subjected to peritoneal dialysis once a day for 1 month from 6 months of age (prevention study) or 9 months of age (treatment study). The Aß in the interstitial fluid (ISF) was collected using microdialysis. Behavioural performance, long-term potentiation (LTP), Aß burden and other AD-type pathologies were measured after 1 month of peritoneal dialysis. Peritoneal dialysis significantly reduced plasma Aß levels in both CKD patients and APP/PS1 mice. Aß levels in the brain ISF of APP/PS1 mice immediately decreased after reduction of Aß in the blood during peritoneal dialysis. In both prevention and treatment studies, peritoneal dialysis substantially reduced Aß deposition, attenuated other AD-type pathologies, including Tau hyperphosphorylation, glial activation, neuroinflammation, neuronal loss, and synaptic dysfunction, and rescued the behavioural deficits of APPswe/PS1 mice. Importantly, the Aß phagocytosis function of microglia was enhanced in APP/PS1 mice after peritoneal dialysis. Our study suggests that peritoneal dialysis is a promising therapeutic method for AD, and Aß clearance using a peripheral approach could be a desirable therapeutic strategy for AD.

[Land Use Structure Change and Its Control Effect of Nitrogen Output in a Small Watershed of Three Gorges Reservoir Area: A Case Study of Lanlingxi Watershed].

The nitrogen (N) output in Lanlingxi watershed of Three Gorges Reservoir Area in 2015 was monitored and the current land use map was investigated. Cluster analysis and correlation analysis were used to identify the major sources of pollutants and to discriminate the source and the sink land use types. The effects of land use on N exports were quantitatively analyzed by stepwise regression analysis. The results showed that: ① After the returning farmland to forest project the land use structure of this area changed dramatically. The area proportions of forest land and garden plot increased to 76.85% and 13.87% respectively, and the proportion of cultivated land dropped to 1.16%. Cultivated lands were stellate distributed and garden plots in some catchments were flake distributed. ② The content of TN in some monitoring points surpassed the Class V standard of the national groundwater environmental quality. The ammonium-N (NH4+-N) concentrations ranged 0.089-0.214 mg·L-1, 2.925-13.203 mg·L-1 for nitrate-N (NO3--N) and 3.561-14.572 mg·L-1 for total-N (TN). And NO3--N accounted for more than 80% of TN. ③ There were significant positive correlations between garden plot, residential land and N loss, and negative correlations between forest land, unutilized land and N export, which indicated that the former were N sources and the latter were sinks. ④ Forest land area should be increased and garden plot should be controlled, and the area ratio of residential land should be kept below 5% when adjusting land use structure of this watershed. Moreover, forest-tea and forest-fruits modes should be applied to change single land use type of garden plot in some catchments.

[Control of Soil Nutrient Loss of Typical Reforestation Patterns Along the Three Gorges Reservoir Area].

Annual soil nutrient loss characteristics on typical reforestation patterns in watershed along the Three Gorges Reservoir Area were studied based on runoff plot experiment. Runoff and sediment nutrition content from May to October 2014 of typical reforestation patterns including garden plot (tea garden), forest land (Chinese chestnut) and the original slope farmland were determined and then analyzed. The results showed that: (1) After the Returning Farmland to Forest Project the quantity of annual soil nutrient (nitrogen and phosphorus, the sum of them in sediment and runoff) loss decreased. The output of total nitrogen (TN) was in the order of slope farmland (2 444.27 g x hm(-2)) > tea garden (998.70 g x hm(-2)) > Chinese chestnut forest (532.61 g x hm(-2)), and for total phosphorus (TP) loss was slope farmland (1 690.48 g x hm(-2)) > tea garden (488.06 g x hm(-2)) > Chinese chestnut forest (129.00 g x hm(-2)) . Compared with slope farmland, the load of TN and TP output of reforestation patterns decreased 68.68% and 81.75%, respectively. (2) Compared with slope farmland, available nitrogen loss decreased in reforestation patterns. Total nitrate nitrogen (NO3(-)-N) loss ranked in the order of slope farmland (113.79 g x hm(-2)) > tea garden (73.75 g x hm(-2)) > Chinese chestnut forest (56.06 g x hm(-2)) The largest amount of ammonium nitrogen (NH4(+)-N) was found in tea garden (69.34 g x hm(-2)), then in farmland (52.45 g x hm(-2)), and the least in Chinese chestnut forest (47.23 g x hm(-2)). (3) The main route of NO3(-)-N and NH4(+)-N loss was both through runoff, the quantity of NO3(-)-N and NH4(+)-N output in which accounted for 91.4% and 92.2% of the total, respectively. The quantity of TN and TP in sediment accounted for 86.6% and 98.4% of the total. TN and TP loss showed an extremely significant correlation with sediments, which showed that sediment output was the main approach of TN and TP loss.

[Effects of land use and landscape pattern on nitrogen and phosphorus exports in Lanlingxi Watershed of the Three Gorges Reservoir Area, China].

The temporal and spatial characteristics of N, P exports and effects of land use and landscape pattern on N, P exports were analyzed in the Lanlingxi Watershed of the Three Gorges Reservoir Area. The results showed that the TN, TP and NO3(-) -N were mainly generated by non-wood forest, the N, P exports in flood period (June to September) were significantly higher than the non-flood period (January to May). The NH4(+) -N export was derived from the residential area in the non-flood period, while from non-wood forest in the flood period. In addition, the performance of samples N, P exports with forest distributed were lower in both two periods. Also, the proportion of forest significantly negatively correlated with NO3(-) -N, TP in the non-flood period and TN, TP in the flood period. The residential area proportion notably positively correlated with NO3(-) -N, TN in non-flood period and NO3(-) -N, TN, TP in the flood period. The non-wood forest proportion also significantly positively correlated with NH4(+) -N, TN in the flood period. Moreover, PD closely positively correlated with N exports in non-flood period, with NO3(-) -N, NH4(+) -N in flood period. The CONT index strongly negatively correlated with N exports in flood period and TP in non-flood period. However, the proportions of farmland, unused land and the indices of ED were relatively weakened with N, P exports in both periods, while SHMN and water proportion did not show any positive or negative correlation. Moreover, the regression fitting degree of NH4(+)-N was superior to NO3(-) -N, TN and TP with the adjust R2 of 0.885 and 0.969 in two periods, while the regression relation was better than that of non-flood period. The result of redundancy analysis further demonstrated that the landscape fragmentation caused by patches types of different land uses could better explain impacts on the exports of nitrogen and phosphorus. The two canonical axes accumulated explained the 90% proportion of the variables and the highest contribution was PD, which was an important indicator for watershed water quality assessment and prediction.

[Remote sensing analysis of forest resources characteristics in main ecological restoration counties in the Three-gorge area based on the 2nd-class inventory data].

Based on high-resolution SPOT-5 images, combined with topographic (1:10000) calculating terrain-bit index, the distribution characteristics of woodlands in different terrain niches, and the buffer radii of different roads, water bodies and settlements were identified by using ArcGIS space overlay and buffer analysis function. Results showed that woodland resources were abundant, and arbor woodland and shrub land were the main species, which mainly distributed in two mountain areas (Fangdou Mountain, Qiyao Mountain) affected by topographic restriction and woodland natural basis. The woodland terrain niche distribution index showed an overall upward trend with increasing terrain niche gradient, especially for the arbor woodland and shrub land, while the other woodland types presented an opposite trend. The percentage of woodland area occupying the corresponding buffer radius around the roads, waterbodies and settlements had a strong similarity with the woodland terrain niche distribution index. Only around the settlements, bamboo forest, sparse woodland and immature woodland occupied higher percentages of the woodland area of the corresponding buffer radius than that of arbor woodland and shrub land. Woodland distribution was mainly controlled by large landform patterns of mountain features, while the distribution of woodlands in the different terrain niches and the different buffer radii of roads, waterbodies and settlements were driven mainly by duress of human activities under the auspices of the large landform patterns.

[Research progress on remote sensing of ecological and environmental changes in the Three Gorges Reservoir area, China].

The Three Gorges Reservoir area (TGR area) , one of the most sensitive ecological zones in China, has dramatically changes in ecosystem configurations and services driven by the Three Gorges Engineering Project and its related human activities. Thus, understanding the dynamics of ecosystem configurations, ecological processes and ecosystem services is an attractive and critical issue to promote regional ecological security of the TGR area. The remote sensing of environment is a promising approach to the target and is thus increasingly applied to and ecosystem dynamics of the TGR area on mid- and macro-scales. However, current researches often showed controversial results in ecological and environmental changes in the TGR area due to the differences in remote sensing data, scale, and land-use/cover classification. Due to the complexity of ecological configurations and human activities, challenges still exist in the remote-sensing based research of ecological and environmental changes in the TGR area. The purpose of this review was to summarize the research advances in remote sensing of ecological and environmental changes in the TGR area. The status, challenges and trends of ecological and environmental remote-sensing in the TGR area were further discussed and concluded in the aspect of land-use/land-cover, vegetation dynamics, soil and water security, ecosystem services, ecosystem health and its management. The further researches on the remote sensing of ecological and environmental changes were proposed to improve the ecosystem management of the TGR area.

[Characteristics of nutrient loss of Lanlingxi watershed in the Three Gorges Reservoir area].

The water flow velocity of part of the tributaries in the Three Gorges Reservoir area has become slower after the water storage period, and agricultural non-point source pollution (AGNPS) is an urgent problem to be solved. Based on a closed catchment of Lanlingxi watershed, the process and the load of nitrogen and phosphorus loss were monitored, and the different ways of nitrogen (N) and phosphorus (P) loss under typical rainfall conditions in watershed scale were compared. The results showed that: (1) The concentration of total nitrogen (TN) gradually decreased with the increasing runoff, and slowly increased after the rain stopped, while the total phosphorus (TP) was contrary to that of TN; (2) The TN loss process had a close relation with rainfall, as TP loss was influenced by the rainfall intensity. N loss was mainly in the form of dissolvable nitrogen, while particle phosphorus was the dominant form for P loss. (3) Surface runoff was the important way of nutrient loss, as interflow greatly influenced the N loss; (4) Various forms of N and P loss showed a significant linear relationship with runoff. (5) The annual TP loss was 28.94 kg x (a x km)(-2) and TN loss was 1040.41 kg x (a x km2)(-1) in this watershed.

[Nitrogen and phosphorus loss in different land use types and its response to environmental factors in the Three Gorges Reservoir area].

The control of agricultural non-point source pollution (AGNPS) is an urgent problem to be solved for the ecological environment construction in the Three Gorges Reservoir Area. We analyzed the nitrogen (N) and phosphorus (P) loss and its response to environmental factors through monitoring the nutrient loss in different land use types after returning farmland to forest. The results showed that: 1) The variability of nutrient concentration loss was strong in different land use types under different rainfall conditions, and the variability in the concentration of available nutrient was much higher than that of total nutrient; 2) Compared to farmland, the annual phosphorus loss of different land use types was reduced by 84.53% - 91.61% after returning farmland to forest; the reduction of annual nitrogen loss was not significant except Chinese chestnut forest (Castanea mollissima) and arbor forest, and the nitrogen loss was much higher than the phosphorus loss in all land use types; 3) The particle phosphorus and nitrate nitrogen (NO3(-)-N) were the main forms of the phosphorus and nitrogen loss, respectively; 4) The nutrient loss of tea garden (Camellia sinensis) and bamboo forest (Phyllostachys pubescens) showed a good correlation with precipitation, and the correlation of phosphorus was better than that of nitrogen, but there was no significant relation with the rainfall intensity; 5) The coverage of vegetation, tree layer and litter had a great influence on the loss of total nitrogen (TN). NO3(-)-N loss was highly influenced by the ammonium nitrogen (NH4(+)-N) content in the surface soil, and P loss mainly by the total phosphorus (TP) and sand content in the soil.

[Relationships between soil nutrient contents and soil enzyme activities in Pinus massoniana stands with different ages in Three Gorges Reservoir Area].

Based on the measurements of soil nutrient contents and enzyme activities and the canonical correspondence analysis (CCA), this paper studied the relationships between soil nutrient contents and soil enzyme activities in different age Pinus massoniana stands in Three Gorges Reservoir Area. Among the test stands, mature stand had the highest contents of organic matter, total nitrogen, ammonium nitrogen, and available phosphorus in 0-20 cm soil layer, followed by middle-aged stand, and nearly-mature stand. With the increase of the stand age, soil invertase activity increased after an initial decrease, cellulase and polyphenoloxidase activities decreased gradually, while urease and peroxidase activities decreased after an initial increase. CCA analysis showed that the effects of the main soil parameters on the soil enzyme activities in the stands ranked in the sequence of total nitrogen > organic matter > pH > bulk density > ammonium nitrogen > available phosphorus. Soil invertase activity had significant positive correlations with soil organic matter, total nitrogen, and total phosphorus, while soil peroxidase activity significantly negatively correlated with soil organic matter, total nitrogen, total phosphorus, and bulk density. The soil was rich in main nutrients, invertase activity was relatively high, while peroxidase activity was relatively low. The activities of soil invertase, cellulase and peroxidase could be used as the good biological indicators in evaluating soil quality and fertility.

[Effects of litterfall and root input on soil physical and chemical properties in Pinus massoniana plantations in Three Gorges Reservoir Area, China].

An investigation was made on the soil physical and chemical properties in different-aged Pinus massoniana plantations in Three Gorges Reservoir Area under effects of litterfall and roots. The annual litter production in mature stand was 19.4% and 65.7% higher than that in nearly mature and middle-aged stands, respectively. The litter standing amount was in the sequence of mature stand > middle-aged stand > nearly mature stand, while the litter turnover coefficient was in the order of nearly mature stand (0.51) > mature stand (0.40) > middle-aged stand (0.36). The total root biomass, live root biomass, and dead root biomass were the highest in middle-aged stand, and the lowest in nearly mature stand. In middle-aged stand, soil total porosity was the highest, and soil bulk density was the lowest. Soil organic matter and total nitrogen contents were in the order of mature stand > middle-aged stand > nearly mature stand, soil nitrate nitrogen occupied a larger proportion of soil mineral N in nearly mature stand, while ammonium nitrogen accounted more in middle-aged and mature stands. In nearly mature stand, litter production was moderate but turnover coefficient was the highest, and soil nutrient contents were the lowest. In middle-aged stand, root biomass and soil total porosity were the highest, and soil bulk density were the lowest. In mature stand, root biomass was lower while soil nutrient contents were the highest. The increase of root biomass could improve soil physical properties.

[Dynamic change of non-point source pollution exported from Heigou watershed in Three Gorges Reservoir area].

Sediment and its associated pollutants entering a water body can be very destructive to the ecological health of that system. Based on GIS and AnnAGNPS model, A total of 60 combinations of various management treatments including five fertilizer levels (FL1-existing, FL2-70% of existing, FL3-recommended, FLA-70% of recommended, FL5-30% of recommended), four tillage practices (CT-conventional tillage, NT-no tillage, CS-contour strip cropping, RC-residue cover) and three kinds of annual rainfall (deficit, normal, abundant) have been evaluated. Results from model simulations indicate that runoff and sediment yield were not affected due to change in fertilizer doses, but there was a significant positive correlation between nutrient losses and fertilizer application rates; Conservation tillage practices such as NT, CS and RC would reduce sediment and sediment-bound nutrient losses significantly, they have very little benefit on soluble nitrogen and phosphorus losses. This is primarily because the increased infiltration rates resulting from those practices leads to greater losses of subsurface and return flow in the watershed. In view of feasibility and efficiency, the combination of FL3 + NT was found to be the best scenario as the reductions of nutrient losses and sediment yield were about 40% and 45%, respectively.

[Reduction effects of agricultural management practices on non-point source pollution in a watershed in Three Gorges Reservoir Area].

Taking a typical watershed in the Three Gorges Reservoir Area (TGRA) as test object, the AnnAGNPS model was used to evaluate the reduction effects of different cropping, different fertilization level, conservation tillage practice (CTP), conservation reserve program (CRP), and conversion of cropland into forestland program (CCFP) on the output of agricultural non-point source pollution (NPS) in the watershed. The simulation results showed that different cropping had no significant difference in the effect of reducing sediment yield, but had significant difference in the effect of reducing phosphorus output. Fertilization level had significant effects on the outputs of total nitrogen and total phosphorus. CTP decreased the sediment yield significantly but increased the nutrient output. CRP reduced sediment yield, but had less effect in reducing nutrient output. CCFP reduced both sediment yield and nutrient output significantly. After the implementation of CCFP, the sediment yield output on the croplands with a slope greater than 10 degrees was less than 5 t x hm(-2) and the nutrient output was within the permissible limit.

[Nonpoint source pollution model, AnnAGNPS, assessment for a mixed forested watershed in Three Gorges Reservoir area].

Watershed models provide a cost-effective and efficient means of estimating the pollutant loadings entering surface waters, especially when combined with traditional water quality sampling and analyses. But there have often been questions about the accuracy or certainty of models and their predictions. The main goal of this study was to evaluate the performance of AnnAGNPS (Annualized AGricultural NonPoint Source)Pollution Model, in simulating runoff, sediment loading and nutrient loadings under Three Gorges Reservoir area. Most of model input parameters were sourced from Zigui Forest Ecology Station in Three Gorges Reservoir area, State Forestry Administration. Data year 2003 was used for calibration while data year 2004 was used for validation of the model. The whole evaluation consisted of determining the coefficient of determination (R2), Nash-Sutcliffe coefficient of efficiency (E), and the percentage volume error (VE). Results showed that the model predicted the daily runoff volume within the range of acceptable accuracy. The runoff on a daily basis was underpredicted by 5.0% with R2 of 0.93 (p < 0.05) during calibration and underpredicted by 6.7% with R2 of 0.90 (p < 0.05) during validation. But sediment loading was able to produce a moderate result. The model underpredicted the event-based sediment loading by 15.1% with R2 of 0.63 (p < 0.05) during calibration and 26.7% with R2 of 0.59 (p < 0.05) during validation. For the events of small magnitude, the model generally overpredicted sediment loading, while the opposite was true for larger events. Nitrogen loading prediction was slightly better with R2 = 0.68 (p < 0.05), and phosphorus loading performance was slightly poor with R2 = 0.65 (p < 0.05). In general, the model performs well in simulating runoff compare to sediment loading and nutrient loadings, and as a watershed management tools it can be used for Three Gorges Reservoir area conditions that with mixed types of land uses and steep slopes.