In this study, the water balance-based Precipitation-Evapotranspiration-Runoff (PER) method combined with the land surface model Variable Infiltration Capacity (VIC) was used to estimate the spatiotemporal variations ...In this study, the water balance-based Precipitation-Evapotranspiration-Runoff (PER) method combined with the land surface model Variable Infiltration Capacity (VIC) was used to estimate the spatiotemporal variations of terrestrial water storage (TWS) for two periods, 1982-2005 (baseline) and 2071-2100, under future climate scenarios A2 and B2 in the Yangtze River basin. The results show that the estimated TWS during the baseline period and under the two future climate scenarios have similar seasonal amplitudes of 60-70 mm. The higher values of TWS appear in June during the baseline period and under the B2 scenario, whereas the TWS under A2 shows two peaks in response to the related precipitation pattern. It also shows that the TWS is recharged from February to June during the baseline period, but it is replenished from March to June under the A2 and B2 scenarios. An analysis of the standard derivation of seasonal and interannual TWS time series under the three scenarios demonstrates that the seasonal TWS of the southeastern part of the Yangtze River basin varies remarkably and that the southeastern and central parts of the basin have higher variations in interannual TWS. With respect to the first mode of the Empirical Orthogonal Function (EOF), the inverse-phase change in seasonal TWS mainly appears across the Guizhou-Sichuan-Shaanxi belt, and the entire basin generally represents a synchronous change in interannual TWS. As a whole, the TWS under A2 presents a larger seasonal variation whereas that under B2 displays a greater interannual variation. These results imply that climate change could trigger severe disasters in the southeastern and central parts of the basin.展开更多
Pancreatic cancer is difficult to diagnose at an early stage and is associated with a very poor survival.Ten percent of pancreatic cancers result from genetic susceptibility and/or familial aggregation.Individuals fro...Pancreatic cancer is difficult to diagnose at an early stage and is associated with a very poor survival.Ten percent of pancreatic cancers result from genetic susceptibility and/or familial aggregation.Individuals from families with multiple affected first-degree relatives and those with a known cancer-causing genetic mutation have been shown to be at much higher risk of developing pancreatic cancer.Recent efforts have focused on detecting disease at an earlier stage to improve survival in these high-risk groups.This article reviews high-risk groups,screening methods,and current screening programs and their results.展开更多
Objective To evaluate the variation of serum activin A level in liver cirrhotic patients.Methods 83 liver cirrhotic patients (32 Child-Pugh A, 30 Child-Pugh B and 21 Child-Push C) and 32 normal subjects entered the st...Objective To evaluate the variation of serum activin A level in liver cirrhotic patients.Methods 83 liver cirrhotic patients (32 Child-Pugh A, 30 Child-Pugh B and 21 Child-Push C) and 32 normal subjects entered the study. The serum levels of activin A, procollagen Ⅲ peptide and collagen Ⅳ were measured by ELISA. Results Compared with those of normal subjects (0. 76±0. 31ng/ml) ,the serum activin A levels were significantly increased in liver cirrhotic patients(1. 33±0. 83ng/ml, P <0. 01). The levels were higher in Child-Pugh C (1. 45±0. 39ng/ml, P <0. 01) and B( 1. 47±0. 81ng/ml, P <0. 01) than in Child-Pugh A (1.00±0. 35 ng/ml) and normal control group(0. 76±0. 31ng/ml). There was no significant difference between Child-Pugh B and C patients or between Child-Pugh A patients and normal control. In corresponding Child-Pugh grades, the serum activin A levels of those suffering from hepatic encephalopathy, digestive tract hemorrhage, infection or ascites were not different from those without such complications. The Serum activin A level was positively correlated with those of procollagen Ⅲ peptides, collagen Ⅳ and alanine aminotransferase. Conclusion Serum activin A was increased in cirrhotic patients and activin A may be involved in the pathogenesis of hepatic flbrosis.展开更多
Many stock exchanges around the world enforcing daily price limits on the amount asset prices can change to prevent the market from overreacting and to reduce volatility. Price limits are artificial boundaries set by ...Many stock exchanges around the world enforcing daily price limits on the amount asset prices can change to prevent the market from overreacting and to reduce volatility. Price limits are artificial boundaries set by market regulators who restrict price changes of a stock to a pre-specified range during a trading day or a single trading session. The primary aim of price limit rules is to stabilize the markets during panic trading, to moderate vitality by repressing excessive speculation, and to allow stocks to be traded at prices close to their fair value. However, their impact on the market is a somewhat unresolved issue （Harris, 1998）. Using a methodology of comparing volatility based on the extreme value technique, the authors empirically investigate the impact of price limits on the volatility of the Stock Exchange of Thailand. The empirical results support price limits advocates, suggesting that price limits rules moderate stock price volatility.展开更多
基金supported by the National Basic Research Program of China under Grants 2010CB951001 and 2010CB428403the National Natural Science Foundation of China under Grant 41075062the R&D Special Fund for Public Welfare Industry (Meteorology) under Grant GYHY201006037
文摘In this study, the water balance-based Precipitation-Evapotranspiration-Runoff (PER) method combined with the land surface model Variable Infiltration Capacity (VIC) was used to estimate the spatiotemporal variations of terrestrial water storage (TWS) for two periods, 1982-2005 (baseline) and 2071-2100, under future climate scenarios A2 and B2 in the Yangtze River basin. The results show that the estimated TWS during the baseline period and under the two future climate scenarios have similar seasonal amplitudes of 60-70 mm. The higher values of TWS appear in June during the baseline period and under the B2 scenario, whereas the TWS under A2 shows two peaks in response to the related precipitation pattern. It also shows that the TWS is recharged from February to June during the baseline period, but it is replenished from March to June under the A2 and B2 scenarios. An analysis of the standard derivation of seasonal and interannual TWS time series under the three scenarios demonstrates that the seasonal TWS of the southeastern part of the Yangtze River basin varies remarkably and that the southeastern and central parts of the basin have higher variations in interannual TWS. With respect to the first mode of the Empirical Orthogonal Function (EOF), the inverse-phase change in seasonal TWS mainly appears across the Guizhou-Sichuan-Shaanxi belt, and the entire basin generally represents a synchronous change in interannual TWS. As a whole, the TWS under A2 presents a larger seasonal variation whereas that under B2 displays a greater interannual variation. These results imply that climate change could trigger severe disasters in the southeastern and central parts of the basin.
文摘Pancreatic cancer is difficult to diagnose at an early stage and is associated with a very poor survival.Ten percent of pancreatic cancers result from genetic susceptibility and/or familial aggregation.Individuals from families with multiple affected first-degree relatives and those with a known cancer-causing genetic mutation have been shown to be at much higher risk of developing pancreatic cancer.Recent efforts have focused on detecting disease at an earlier stage to improve survival in these high-risk groups.This article reviews high-risk groups,screening methods,and current screening programs and their results.
基金Supported by the National Nature Science Foundation of China( 30170411).
文摘Objective To evaluate the variation of serum activin A level in liver cirrhotic patients.Methods 83 liver cirrhotic patients (32 Child-Pugh A, 30 Child-Pugh B and 21 Child-Push C) and 32 normal subjects entered the study. The serum levels of activin A, procollagen Ⅲ peptide and collagen Ⅳ were measured by ELISA. Results Compared with those of normal subjects (0. 76±0. 31ng/ml) ,the serum activin A levels were significantly increased in liver cirrhotic patients(1. 33±0. 83ng/ml, P <0. 01). The levels were higher in Child-Pugh C (1. 45±0. 39ng/ml, P <0. 01) and B( 1. 47±0. 81ng/ml, P <0. 01) than in Child-Pugh A (1.00±0. 35 ng/ml) and normal control group(0. 76±0. 31ng/ml). There was no significant difference between Child-Pugh B and C patients or between Child-Pugh A patients and normal control. In corresponding Child-Pugh grades, the serum activin A levels of those suffering from hepatic encephalopathy, digestive tract hemorrhage, infection or ascites were not different from those without such complications. The Serum activin A level was positively correlated with those of procollagen Ⅲ peptides, collagen Ⅳ and alanine aminotransferase. Conclusion Serum activin A was increased in cirrhotic patients and activin A may be involved in the pathogenesis of hepatic flbrosis.
文摘Many stock exchanges around the world enforcing daily price limits on the amount asset prices can change to prevent the market from overreacting and to reduce volatility. Price limits are artificial boundaries set by market regulators who restrict price changes of a stock to a pre-specified range during a trading day or a single trading session. The primary aim of price limit rules is to stabilize the markets during panic trading, to moderate vitality by repressing excessive speculation, and to allow stocks to be traded at prices close to their fair value. However, their impact on the market is a somewhat unresolved issue （Harris, 1998）. Using a methodology of comparing volatility based on the extreme value technique, the authors empirically investigate the impact of price limits on the volatility of the Stock Exchange of Thailand. The empirical results support price limits advocates, suggesting that price limits rules moderate stock price volatility.
