This paper applied an integrated method combining grey relation analysis, wavelet analysis and statistical analysis to study climate change and its effects on runoff of the Kaidu River at multi-time scales. Major find...This paper applied an integrated method combining grey relation analysis, wavelet analysis and statistical analysis to study climate change and its effects on runoff of the Kaidu River at multi-time scales. Major findings are as follows: 1) Climatic factors were ranked in the order of importance to annual runoff as average annual temperature, average temperature in autumn, average temperature in winter, annual precipitation, precipitation in flood season, average temperature in summer, and average temperature in spring. The average annual temperature and annual precipi- tation were selected as the two representative factors that impact the annual runoff. 2) From the 32-year time scale, the annual runoff and the average annual temperature presented a significantly rising trend, whereas the annual precipita- tion showed little increase over the period of 1957-2002. By changing the time scale from 32-year to 4-year, we ob- served nonlinear trends with increasingly obvious oscillations for annual runoff, average annual temperature, and annual precipitation. 3) The changes of the runoff and the regional climate are closely related, indicating that the runoff change is the result of the regional climate changes. With time scales ranging from 32-year, 16-year, 8-year and to 4-year, there are highly significant linear correlations between the annual runoff and the average annual temperature and the annual precipitation.展开更多
Stochastic characteristics of the Benue River streamflow process are examined under conditions of data austerity. The streamflow process is investigated for trend, non-stationarity and seasonality for a time period of...Stochastic characteristics of the Benue River streamflow process are examined under conditions of data austerity. The streamflow process is investigated for trend, non-stationarity and seasonality for a time period of 26 years. Results of trend analyses with Mann-Kendall test show that there is no trend in the annual mean discharges. Monthly flow series examined with seasonal Kendall test indicate the presence of positive change in the trend for some months, especially the months of August, January, and February. For the stationarity test, daily and monthly flow series appear to be stationary whereas at 1%, 5%, and 10% significant levels, the stationarity alternative hypothesis is rejected for the annual flow series. Though monthly flow appears to be stationary going by this test, because of high seasonality, it could be said to exhibit periodic stationarity based on the seasonality analysis. The following conclusions are drawn： （1） There is seasonality in both the mean and variance with unimodal distribution. （2） Days with high mean also have high variance. （3） Skewness coefficients for the months within the dry season period are greater than those of the wet season period, and seasonal autocorrelations for streamflow during dry season are generally larger than those of the wet season. Precisely, they are significantly different for most of the months. （4） The autocorrelation functions estimated ＂over time＂ are greater in the absolute value for data that have not been deseasonalised but were initially normalised by logarithmic transformation only, while autocorrelation functions for i = 1, 2 365 estimated ＂over realisations＂ have their coefficients significantly different from other coefficients.展开更多
In this paper, a coupled model was used to estimate the responses of soil moisture and net primary production of vegetation(NPP) to increasing atmospheric CO2 concentration and climate change. The analysis uses three ...In this paper, a coupled model was used to estimate the responses of soil moisture and net primary production of vegetation(NPP) to increasing atmospheric CO2 concentration and climate change. The analysis uses three experiments simulated by the second-generation Earth System Model(CanESM2) of the Canadian Centre for Climate Modelling and Analysis(CCCma), which are part of the phase 5 of the Coupled Model Intercomparison Project(CMIP5). The authors focus on the magnitude and evolution of responses in soil moisture and NPP using simulations modeled by CanESM, in which the individual effects of increasing CO2 concentration and climate change and their combined effect are separately accounted for. When considering only the single effect of climate change, the soil moisture and NPP have a linear trend of 0.03 kg m–2 yr–1 and –0.14 gC m–2 yr–2, respectively. However, such a reduction in the global NPP results from the decrease of NPP at lower latitudes and in the Southern Hemisphere, although increased NPP has been shown in high northern latitudes. The largest negative trend is located in the Amazon basin at –1.79 gC m–2 yr–2. For the individual effect of increasing CO2 concentration, both soil moisture and NPP show increases, with an elevated linear trend of 0.02 kg m–2 yr–1 and 0.84 gC m–2 yr–2, respectively. Most regions show an increasing NPP, except Alaska. For the combined effect of increasing atmospheric CO2 and climate change, the increased soil moisture and NPP exhibit a linear trend of 0.04 kg m–2 yr–1 and 0.83 gC m–2 yr–2 at a global scale. In the Amazon basin, the higher reduction in soil moisture is illustrated by the model, with a linear trend of –0.39 kg m–2 yr–1, for the combined effect. Such a change in soil moisture is caused by a weakened Walker circulation simulated by this coupled model, compared with the single effect of increasing CO2 concentration(experiment M2), and a consequence of the reduction in NPP is also shown in this area, with a linear trend of-0.16 gC m-2 yr-2.展开更多
OBJECTIVE: To observe the effects of serum containing Mahuang(Herba Ephedra Sinica) or Wuweizi(Fructus Schisandrae Chinensis) on the migration of alveolar macrophages(AM) and interstitial macrophages(IM) from normal r...OBJECTIVE: To observe the effects of serum containing Mahuang(Herba Ephedra Sinica) or Wuweizi(Fructus Schisandrae Chinensis) on the migration of alveolar macrophages(AM) and interstitial macrophages(IM) from normal rats, and to analyze and compare the mechanisms leading to cell migration differences.METHODS: Rats were randomly divided into three groups: Mahuang(Herba Ephedra Sinica), Wuweizi(Fructus Schisandrae Chinensis), and blank serum. After treatment with the herbs, serum was extracted from the rats. AM and IM were isolated from normal rats and cultured. The effects of Mahuang(Herba Ephedra Sinica) and Wuweizi(Fructus Schisandrae Chinensis) medicated serum on normal rat AM and IM chemotactic migration were determined by transwell assays. The CC chemokine receptor(CCR) 2, CCR5, voltage-gated Kvl. 3 K^+channel(Kv1. 3), and voltage-gated Kvl. 5 K^+channel(Kv1. 5) protein levels were analyzed by western blotting.RESULTS: The migration quantities of AM and IM in the Mahuang(Herba Ephedra Sinica) and Wuweizi(Fructus Schisandrae Chinensis) medicated serum groups were significantly higher than those in the blank serum group(P < 0.01). Compared with the Wuweizi(Fructus Schisandrae Chinensis) medicated serum group, the migration quantity of cultured rat AM in the Mahuang(Herba Ephedra Sinica) medicated serum group was significantly increased(P <0.01). Meanwhile, compared with the Mahuang(Herba Ephedra Sinica) medicated serum group, the migration quantity of cultured rat IM in the Wuweizi(Fructus Schisandrae Chinensis) medicated serum group was significantly increased(P < 0.01).CCR2, CCR5, Kv1. 3, and Kv1. 5 proteins were expressed on the AM cell surface, and showed significantly higher expression in the Mahuang(Herba Ephedra Sinica) medicated serum group compared with the Wuweizi(Fructus Schisandrae Chinensis)medicated serum group. In contrast, CCR5, Kv1.3,and Kv1.5 proteins were expressed on the IM cell surface, and showed significantly higher expression in the Wuweizi(Fructus Schisandrae Chinensis)medicated serum group compared with the Mahuang(Herba Ephedra Sinica) medicated serum group.CONCLUSION: Mahuang(Herba Ephedra Sinica)and Wuweizi(Fructus Schisandrae Chinensis) can promote AM and IM migration ability, with Mahuang(Herba Ephedra Sinica) targeting AM more apparently and Wuweizi(Fructus Schisandrae Chinensis) targeting IM more apparently. The mechanism may be that, by stimulating cells, Mahuang(Herba Ephedra Sinica) and Wuweizi(Fructus Schisandrae Chinensis) promote expression of CCR2 and CCR5 receptors on the AM and IM cell surface,which pass signals to Kvl.3 and Kvl.5 ion channels,leading to changes in the cytoskeleton, and ultimately promoting chemotactic cell migration.展开更多
Background and aims:Acute cholecystitis is a fairly common inpatient diagnosis among the gastrointestinal disorders.The aim of this study was to use a national database of US hospitals to evaluate the incidence and co...Background and aims:Acute cholecystitis is a fairly common inpatient diagnosis among the gastrointestinal disorders.The aim of this study was to use a national database of US hospitals to evaluate the incidence and costs of hospital admissions associated with acute cholecystitis.Method:We analyzed the National Inpatient Sample Database(NIS)for all patients in which acute cholecystitis(ICD-9 codes:574.00,574.01,574.30,574.31,574.60,574.61 or 575.0)was the principal discharge diagnosis from 1997 to 2012.The NIS is the largest all-payer inpatient database in the United States and contains data from approximately 8 million hospital stays each year.The statistical significance of the difference in the number of hospital discharges,lengths of stay and associated hospital costs over the study period was determined by using the Chi-square test for trends.Results:In 1997,there were 149661 hospital admissions with a principal discharge diagnosis of acute cholecystitis,which increased to 215995 in 2012(P<0.001).The mean length of stay for acute cholecystitis decreased by 17% between 1997 and 2012(i.e.from 4.7 days to 3.9 days);(P<0.05).During the same time period,however,mean hospital charges have increased by 195.4% from US$14608 per patient in 1997 to US$43152 per patient in 2012(P<0.001).Conclusion:The number of inpatient discharges related to acute cholecystitis has increased significantly in the United States over the last 16 years,along with a great increase in the associated hospital charges.However,there has been a gradual decline in the mean length of stay.Inpatient costs associated with acute cholecystitis contribute significantly to the total healthcare bill.Further research on cost-effective evaluation and management of acute cholecystitis is required.展开更多
基金Under the auspices of Second-stage Knowledge Innovation Program of Chinese Academy of Sciences (No. KZCX2-XB2-03)the major direction of Knowledge Innovation Program of Chinese Academy of Sciences (No. KZCX2-YW- 127)Shanghai Academic Discipline Project (Human Geography) (No. B410)
文摘This paper applied an integrated method combining grey relation analysis, wavelet analysis and statistical analysis to study climate change and its effects on runoff of the Kaidu River at multi-time scales. Major findings are as follows: 1) Climatic factors were ranked in the order of importance to annual runoff as average annual temperature, average temperature in autumn, average temperature in winter, annual precipitation, precipitation in flood season, average temperature in summer, and average temperature in spring. The average annual temperature and annual precipi- tation were selected as the two representative factors that impact the annual runoff. 2) From the 32-year time scale, the annual runoff and the average annual temperature presented a significantly rising trend, whereas the annual precipita- tion showed little increase over the period of 1957-2002. By changing the time scale from 32-year to 4-year, we ob- served nonlinear trends with increasingly obvious oscillations for annual runoff, average annual temperature, and annual precipitation. 3) The changes of the runoff and the regional climate are closely related, indicating that the runoff change is the result of the regional climate changes. With time scales ranging from 32-year, 16-year, 8-year and to 4-year, there are highly significant linear correlations between the annual runoff and the average annual temperature and the annual precipitation.
基金Supported by the Post Graduate Research Fund from Federal Government of Nigeria under the BEA Scholarship Program （No.CSC2005566002）
文摘Stochastic characteristics of the Benue River streamflow process are examined under conditions of data austerity. The streamflow process is investigated for trend, non-stationarity and seasonality for a time period of 26 years. Results of trend analyses with Mann-Kendall test show that there is no trend in the annual mean discharges. Monthly flow series examined with seasonal Kendall test indicate the presence of positive change in the trend for some months, especially the months of August, January, and February. For the stationarity test, daily and monthly flow series appear to be stationary whereas at 1%, 5%, and 10% significant levels, the stationarity alternative hypothesis is rejected for the annual flow series. Though monthly flow appears to be stationary going by this test, because of high seasonality, it could be said to exhibit periodic stationarity based on the seasonality analysis. The following conclusions are drawn： （1） There is seasonality in both the mean and variance with unimodal distribution. （2） Days with high mean also have high variance. （3） Skewness coefficients for the months within the dry season period are greater than those of the wet season period, and seasonal autocorrelations for streamflow during dry season are generally larger than those of the wet season. Precisely, they are significantly different for most of the months. （4） The autocorrelation functions estimated ＂over time＂ are greater in the absolute value for data that have not been deseasonalised but were initially normalised by logarithmic transformation only, while autocorrelation functions for i = 1, 2 365 estimated ＂over realisations＂ have their coefficients significantly different from other coefficients.
基金supported by the project of the National Natural Science Foundation of China (Grant Nos. 41275082 and 41305070)the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA05110103)the Knowledge Innovation Program of the Chinese Academy of Sciences (Grant Nos. KZCX2-EW-QN208 and 7-122158)
文摘In this paper, a coupled model was used to estimate the responses of soil moisture and net primary production of vegetation(NPP) to increasing atmospheric CO2 concentration and climate change. The analysis uses three experiments simulated by the second-generation Earth System Model(CanESM2) of the Canadian Centre for Climate Modelling and Analysis(CCCma), which are part of the phase 5 of the Coupled Model Intercomparison Project(CMIP5). The authors focus on the magnitude and evolution of responses in soil moisture and NPP using simulations modeled by CanESM, in which the individual effects of increasing CO2 concentration and climate change and their combined effect are separately accounted for. When considering only the single effect of climate change, the soil moisture and NPP have a linear trend of 0.03 kg m–2 yr–1 and –0.14 gC m–2 yr–2, respectively. However, such a reduction in the global NPP results from the decrease of NPP at lower latitudes and in the Southern Hemisphere, although increased NPP has been shown in high northern latitudes. The largest negative trend is located in the Amazon basin at –1.79 gC m–2 yr–2. For the individual effect of increasing CO2 concentration, both soil moisture and NPP show increases, with an elevated linear trend of 0.02 kg m–2 yr–1 and 0.84 gC m–2 yr–2, respectively. Most regions show an increasing NPP, except Alaska. For the combined effect of increasing atmospheric CO2 and climate change, the increased soil moisture and NPP exhibit a linear trend of 0.04 kg m–2 yr–1 and 0.83 gC m–2 yr–2 at a global scale. In the Amazon basin, the higher reduction in soil moisture is illustrated by the model, with a linear trend of –0.39 kg m–2 yr–1, for the combined effect. Such a change in soil moisture is caused by a weakened Walker circulation simulated by this coupled model, compared with the single effect of increasing CO2 concentration(experiment M2), and a consequence of the reduction in NPP is also shown in this area, with a linear trend of-0.16 gC m-2 yr-2.
基金Supported by The National Natural Science Foundation of China(No.81373887)The Traditional Chinese Medicine Standardization Project of the State Administration of Traditional Chinese Medicine(No.ZYXX-2014)The Beijing Municipal Administration of Traditional Chinese Medicine"Generation 3+3"Project-Jin Shiyuan the Well-Known Old Man Chinese Medicine Studio Station(Beijing University of Chinese Medicine)Construction Project
文摘OBJECTIVE: To observe the effects of serum containing Mahuang(Herba Ephedra Sinica) or Wuweizi(Fructus Schisandrae Chinensis) on the migration of alveolar macrophages(AM) and interstitial macrophages(IM) from normal rats, and to analyze and compare the mechanisms leading to cell migration differences.METHODS: Rats were randomly divided into three groups: Mahuang(Herba Ephedra Sinica), Wuweizi(Fructus Schisandrae Chinensis), and blank serum. After treatment with the herbs, serum was extracted from the rats. AM and IM were isolated from normal rats and cultured. The effects of Mahuang(Herba Ephedra Sinica) and Wuweizi(Fructus Schisandrae Chinensis) medicated serum on normal rat AM and IM chemotactic migration were determined by transwell assays. The CC chemokine receptor(CCR) 2, CCR5, voltage-gated Kvl. 3 K^+channel(Kv1. 3), and voltage-gated Kvl. 5 K^+channel(Kv1. 5) protein levels were analyzed by western blotting.RESULTS: The migration quantities of AM and IM in the Mahuang(Herba Ephedra Sinica) and Wuweizi(Fructus Schisandrae Chinensis) medicated serum groups were significantly higher than those in the blank serum group(P < 0.01). Compared with the Wuweizi(Fructus Schisandrae Chinensis) medicated serum group, the migration quantity of cultured rat AM in the Mahuang(Herba Ephedra Sinica) medicated serum group was significantly increased(P <0.01). Meanwhile, compared with the Mahuang(Herba Ephedra Sinica) medicated serum group, the migration quantity of cultured rat IM in the Wuweizi(Fructus Schisandrae Chinensis) medicated serum group was significantly increased(P < 0.01).CCR2, CCR5, Kv1. 3, and Kv1. 5 proteins were expressed on the AM cell surface, and showed significantly higher expression in the Mahuang(Herba Ephedra Sinica) medicated serum group compared with the Wuweizi(Fructus Schisandrae Chinensis)medicated serum group. In contrast, CCR5, Kv1.3,and Kv1.5 proteins were expressed on the IM cell surface, and showed significantly higher expression in the Wuweizi(Fructus Schisandrae Chinensis)medicated serum group compared with the Mahuang(Herba Ephedra Sinica) medicated serum group.CONCLUSION: Mahuang(Herba Ephedra Sinica)and Wuweizi(Fructus Schisandrae Chinensis) can promote AM and IM migration ability, with Mahuang(Herba Ephedra Sinica) targeting AM more apparently and Wuweizi(Fructus Schisandrae Chinensis) targeting IM more apparently. The mechanism may be that, by stimulating cells, Mahuang(Herba Ephedra Sinica) and Wuweizi(Fructus Schisandrae Chinensis) promote expression of CCR2 and CCR5 receptors on the AM and IM cell surface,which pass signals to Kvl.3 and Kvl.5 ion channels,leading to changes in the cytoskeleton, and ultimately promoting chemotactic cell migration.
文摘Background and aims:Acute cholecystitis is a fairly common inpatient diagnosis among the gastrointestinal disorders.The aim of this study was to use a national database of US hospitals to evaluate the incidence and costs of hospital admissions associated with acute cholecystitis.Method:We analyzed the National Inpatient Sample Database(NIS)for all patients in which acute cholecystitis(ICD-9 codes:574.00,574.01,574.30,574.31,574.60,574.61 or 575.0)was the principal discharge diagnosis from 1997 to 2012.The NIS is the largest all-payer inpatient database in the United States and contains data from approximately 8 million hospital stays each year.The statistical significance of the difference in the number of hospital discharges,lengths of stay and associated hospital costs over the study period was determined by using the Chi-square test for trends.Results:In 1997,there were 149661 hospital admissions with a principal discharge diagnosis of acute cholecystitis,which increased to 215995 in 2012(P<0.001).The mean length of stay for acute cholecystitis decreased by 17% between 1997 and 2012(i.e.from 4.7 days to 3.9 days);(P<0.05).During the same time period,however,mean hospital charges have increased by 195.4% from US$14608 per patient in 1997 to US$43152 per patient in 2012(P<0.001).Conclusion:The number of inpatient discharges related to acute cholecystitis has increased significantly in the United States over the last 16 years,along with a great increase in the associated hospital charges.However,there has been a gradual decline in the mean length of stay.Inpatient costs associated with acute cholecystitis contribute significantly to the total healthcare bill.Further research on cost-effective evaluation and management of acute cholecystitis is required.
