Most large-scale evapotranspiration(ET)estimation methods require detailed information of land use,land cover,and/or soil type on top of various atmospheric measurements.The complementary relationship of evaporation(C...Most large-scale evapotranspiration(ET)estimation methods require detailed information of land use,land cover,and/or soil type on top of various atmospheric measurements.The complementary relationship of evaporation(CR)takes advantage of the inherent dynamic feedback mechanisms found in the soil−vegetation−atmosphere interface for its estimation of ET rates without the need of such biogeophysical data.ET estimates over the conterminous United States by a new,globally calibrated,static scaling(GCR-stat)of the generalized complementary relationship(GCR)of evaporation were compared to similar estimates of an existing,calibration-free version(GCR-dyn)of the GCR that employs a temporally varying dynamic scaling.Simplified annual water balances of 327 medium and 18 large watersheds served as ground-truth ET values.With long-term monthly mean forcing,GCR-stat(also utilizing precipitation measurements)outperforms GCR-dyn as the latter cannot fully take advantage of its dynamic scaling with such data of reduced temporal variability.However,in a continuous monthly simulation,GCR-dyn is on a par with GCR-stat,and especially excels in reproducing long-term tendencies in annual catchment ET rates even though it does not require precipitation information.The same GCR-dyn estimates were also compared to similar estimates of eight other popular ET products and they generally outperform all of them.For this reason,a dynamic scaling of the GCR is recommended over a static one for modeling long-term behavior of terrestrial ET.展开更多
The complementary relationship for estimating evapotranspiration (ET) is a simple approach requiring only commonly available meteorological data;however, most complementary relationship models decrease in predictive p...The complementary relationship for estimating evapotranspiration (ET) is a simple approach requiring only commonly available meteorological data;however, most complementary relationship models decrease in predictive power with increasing aridity. In this study, a previously developed Granger and Gray (GG) model by using Budyko framework is further improved to estimate ET under a variety of climatic conditions. This updated GG model, GG-NDVI, includes Normalized Difference Vegetation Index (NDVI), precipitation, and potential evapotranspiration based on the Budyko framework. The Budyko framework is consistent with the complementary relationship and performs well under dry conditions. We validated the GG-NDVI model under operational conditions with the commonly used remote sensing-based Operational Simplified Surface Energy Balance (SSEBop) model at 60 Eddy Covariance AmeriFlux sites located in the USA. Results showed that the Root Mean Square Error (RMSE) for GG-NDVI ranged between 15 and 20 mm/month, which is lower than for SSEBop every year. Although the magnitude of agreement seems to vary from site to site and from season to season, the occurrences of RMSE less than 20 mm/month with the proposed model are more frequent than with SSEBop in both dry and wet sites. Another finding is that the assumption of symmetric complementary relationship is a deficiency in GG-NDVI that may introduce an inherent limitation under certain conditions. We proposed a nonlinear correction function that was incorporated into GG-NDVI to overcome this limitation. As a result, the proposed model produced much lower RMSE values, along with lower RMSE across more sites, as compared to SSEBop.展开更多
Information on the genetic relationship between tropical maize (Zea mays L), germplasm and temperate maize germplasm is of great value to maize breeding. The objective of this study was to determine the combining abil...Information on the genetic relationship between tropical maize (Zea mays L), germplasm and temperate maize germplasm is of great value to maize breeding. The objective of this study was to determine the combining ability and genetic relationship of 25 inbreds extracted from five tropical maize populations and a land race, with four temperate maize inbreds (Huangzaosi, Mol7, B73 and Dan 340). The 25 tropical inbreds were crossed with the four temperate inbreds and evaluated. Lines from Suwanl and POP28 had high general combining ability (GCA) for grain yield. The lines from POP32 (ETO) had the highest special combining ability (SCA) with B73; the average SCA value of the 5 lines was 879 kg/ha. The lines from Suwanl had the second-highest SCA (584 kg/ha) with Huangzaosi. The lines from Suwanl had the greatest relative heterosis (20%) with B73, followed by the lines from POP32 (ETO) with B73 (19%). Five heterotic patterns have been identified from this study: Suwanl × Reid, ETO × Reid, POP28× Reid, POP28× Ludahong-gu, and Suwan1× Lancaster.展开更多
Objective:To calculate the focus absorption dose of 153Sm-EDTMP with the Monte Carlo(MC)EGS4 method for treatment of bone metastases from nasopharyngeal carcinoma or breast cancer,and investigate the relationship betw...Objective:To calculate the focus absorption dose of 153Sm-EDTMP with the Monte Carlo(MC)EGS4 method for treatment of bone metastases from nasopharyngeal carcinoma or breast cancer,and investigate the relationship between the focus absorption dose and painkilling effect of 153Sm-EDTMP.Methods:Four patients with multiple bone metastases from nasopharyngeal or breast carcinoma and suffered from grade IV bone pain were treated with radionuclide internal irradiation of 153Sm-EDTMP.The absorption dose and dose distribution of bone metastases and other targeted organs were calculated with MC EGS4 program based on the time-order SPECT/CT scanning and the measurement of the radioactivity in the urine accumulation.The release of bone pain and the improvement of life quality were observed.Results:Bone pain of the patients was significantly alleviated to grade II for 3–4 weeks after internal 153Sm-EDTMP irradiation.The 3-dimensional absorption dose distribution image of bone metastases and targeted organs showed that the dose distribution in bone metastases was not asymmetrical.After injection of 0.65×37 MBq/kg 153Sm-EDTMP,the highest absorption dose in bone lesions was about 4.9–5.9 Gy,and the dose in the lesion margin was about 2.0 Gy.Using the highest dose as reference dose point,the relative absorption dose values of bone marrow,vertebra and sex organ near lesions were 0.48–1.1 Gy,0.51–0.85 Gy,and 0.01–0.14 Gy,respectively.Conclusion:The absorption dose of bone metastases is significantly lower than treatment dose of 30 Gy after single irradiation of 153Sm-EDTMP.The painkilling effect is limited and in accordance with clinical observation.展开更多
Bouchet in 1963 hypothesized that for large homogeneous land surface with minimum advection of heat and moisture,there exists a 1:1 complementary relationship of potential and actual evaporation coupled through land-a...Bouchet in 1963 hypothesized that for large homogeneous land surface with minimum advection of heat and moisture,there exists a 1:1 complementary relationship of potential and actual evaporation coupled through land-atmosphere feedbacks.The complementary relationship has been widely used to estimate regional actual evaporation and explain the pan evaporation paradox.We examine the standardized potential evaporation(potential evaporation divided by wet environment evaporation) at 102 observatories at different elevations across China.Generally,the relationship is appropriate at the low elevations(<1000 m).With the increase of elevation,vapor transfer power becomes much less than radiation energy budget because of lower vapor pressure deficit and stronger global solar radiation.As a result,at the high elevations(over 1000 m),the excess energy resulted by limited moisture availability is not enough to be converted into drying power of the air.This result suggests that the complementary relationship is asymmetric at the high elevations.展开更多
In the complementary relationship (CR) between actual and potential evapotranspiration, wet envi- ronment evapotranspiration (Ew) is usually calculated using the Priestley-Taylor (P-T) equation. Based on the data obta...In the complementary relationship (CR) between actual and potential evapotranspiration, wet envi- ronment evapotranspiration (Ew) is usually calculated using the Priestley-Taylor (P-T) equation. Based on the data obtained from 38 catchments of the Haihe River basin and the Weishan experiment site in Shandong Province of China, this study has found variations in the Priestley-Taylor parameter α (e.g. increase in values with increase in the amount of precipitation on annual scale, seasonal fluctuation noted to be at a maximum during winter and at a minimum during summer, and increased values in the forenoon and decreased values in the afternoon on an hourly scale). This paper explains that the in- ter-annual variation in α is due to the negative feedback of atmosphere in response to changes in ac- tual increase in evapotranspiration, which is weakened because the atmosphere system is open. The parameter α undergoes a seasonal fluctuation brought about by seasonal changes in advection be- tween continent and ocean; α likewise undergoes a daily variation as a result of atmospheric hysteresis in response to the changes in land surface energy.展开更多
Breast cancer is presently one of the most common malignancies worldwide,with a higher fatality rate.In this study,a quantitative structure-activity relationship(QSAR)model of compound biological activity and ADMET(Ab...Breast cancer is presently one of the most common malignancies worldwide,with a higher fatality rate.In this study,a quantitative structure-activity relationship(QSAR)model of compound biological activity and ADMET(Absorption,Distribution,Metabolism,Excretion,Toxicity)properties prediction model were performed using estrogen receptor alpha(ERα)antagonist information collected from compound samples.We first utilized grey relation analysis(GRA)in conjunction with the random forest(RF)algorithm to identify the top 20 molecular descriptor variables that have the greatest influence on biological activity,and then we used Spearman correlation analysis to identify 16 independent variables.Second,a QSAR model of the compound were developed based on BP neural network(BPNN),genetic algorithm optimized BP neural network(GA-BPNN),and support vector regression(SVR).The BPNN,the SVR,and the logistic regression(LR)models were then used to identify and predict the ADMET properties of substances,with the prediction impacts of each model compared and assessed.The results reveal that a SVR model was used in QSAR quantitative prediction,and in the classification prediction of ADMET properties:the SVR model predicts the Caco-2 and hERG(human Ether-a-go-go Related Gene)properties,the LR model predicts the cytochrome P450 enzyme 3A4 subtype(CYP3A4)and Micronucleus(MN)properties,and the BPNN model predicts the Human Oral Bioavailability(HOB)properties.Finally,information entropy theory is used to validate the rationality of variable screening,and sensitivity analysis of the model demonstrates that the constructed model has high accuracy and stability,which can be used as a reference for screening probable active compounds and drug discovery.展开更多
基金supported by a BMEWater Sciences and Disaster Prevention FIKP grant of EMMI(BME FIKP-VIZ).
文摘Most large-scale evapotranspiration(ET)estimation methods require detailed information of land use,land cover,and/or soil type on top of various atmospheric measurements.The complementary relationship of evaporation(CR)takes advantage of the inherent dynamic feedback mechanisms found in the soil−vegetation−atmosphere interface for its estimation of ET rates without the need of such biogeophysical data.ET estimates over the conterminous United States by a new,globally calibrated,static scaling(GCR-stat)of the generalized complementary relationship(GCR)of evaporation were compared to similar estimates of an existing,calibration-free version(GCR-dyn)of the GCR that employs a temporally varying dynamic scaling.Simplified annual water balances of 327 medium and 18 large watersheds served as ground-truth ET values.With long-term monthly mean forcing,GCR-stat(also utilizing precipitation measurements)outperforms GCR-dyn as the latter cannot fully take advantage of its dynamic scaling with such data of reduced temporal variability.However,in a continuous monthly simulation,GCR-dyn is on a par with GCR-stat,and especially excels in reproducing long-term tendencies in annual catchment ET rates even though it does not require precipitation information.The same GCR-dyn estimates were also compared to similar estimates of eight other popular ET products and they generally outperform all of them.For this reason,a dynamic scaling of the GCR is recommended over a static one for modeling long-term behavior of terrestrial ET.
文摘The complementary relationship for estimating evapotranspiration (ET) is a simple approach requiring only commonly available meteorological data;however, most complementary relationship models decrease in predictive power with increasing aridity. In this study, a previously developed Granger and Gray (GG) model by using Budyko framework is further improved to estimate ET under a variety of climatic conditions. This updated GG model, GG-NDVI, includes Normalized Difference Vegetation Index (NDVI), precipitation, and potential evapotranspiration based on the Budyko framework. The Budyko framework is consistent with the complementary relationship and performs well under dry conditions. We validated the GG-NDVI model under operational conditions with the commonly used remote sensing-based Operational Simplified Surface Energy Balance (SSEBop) model at 60 Eddy Covariance AmeriFlux sites located in the USA. Results showed that the Root Mean Square Error (RMSE) for GG-NDVI ranged between 15 and 20 mm/month, which is lower than for SSEBop every year. Although the magnitude of agreement seems to vary from site to site and from season to season, the occurrences of RMSE less than 20 mm/month with the proposed model are more frequent than with SSEBop in both dry and wet sites. Another finding is that the assumption of symmetric complementary relationship is a deficiency in GG-NDVI that may introduce an inherent limitation under certain conditions. We proposed a nonlinear correction function that was incorporated into GG-NDVI to overcome this limitation. As a result, the proposed model produced much lower RMSE values, along with lower RMSE across more sites, as compared to SSEBop.
基金funded by the Natural Science Foundation of Yunnan Province(980006Z).
文摘Information on the genetic relationship between tropical maize (Zea mays L), germplasm and temperate maize germplasm is of great value to maize breeding. The objective of this study was to determine the combining ability and genetic relationship of 25 inbreds extracted from five tropical maize populations and a land race, with four temperate maize inbreds (Huangzaosi, Mol7, B73 and Dan 340). The 25 tropical inbreds were crossed with the four temperate inbreds and evaluated. Lines from Suwanl and POP28 had high general combining ability (GCA) for grain yield. The lines from POP32 (ETO) had the highest special combining ability (SCA) with B73; the average SCA value of the 5 lines was 879 kg/ha. The lines from Suwanl had the second-highest SCA (584 kg/ha) with Huangzaosi. The lines from Suwanl had the greatest relative heterosis (20%) with B73, followed by the lines from POP32 (ETO) with B73 (19%). Five heterotic patterns have been identified from this study: Suwanl × Reid, ETO × Reid, POP28× Reid, POP28× Ludahong-gu, and Suwan1× Lancaster.
基金grants from the Key Sci-Tech Research Foundationof Guangzhou City(No.2002XZ-J200131)Natural Science Foundationof Guangdong Province(No.031563)National Natural ScienceFoundation(No.10675175).
文摘Objective:To calculate the focus absorption dose of 153Sm-EDTMP with the Monte Carlo(MC)EGS4 method for treatment of bone metastases from nasopharyngeal carcinoma or breast cancer,and investigate the relationship between the focus absorption dose and painkilling effect of 153Sm-EDTMP.Methods:Four patients with multiple bone metastases from nasopharyngeal or breast carcinoma and suffered from grade IV bone pain were treated with radionuclide internal irradiation of 153Sm-EDTMP.The absorption dose and dose distribution of bone metastases and other targeted organs were calculated with MC EGS4 program based on the time-order SPECT/CT scanning and the measurement of the radioactivity in the urine accumulation.The release of bone pain and the improvement of life quality were observed.Results:Bone pain of the patients was significantly alleviated to grade II for 3–4 weeks after internal 153Sm-EDTMP irradiation.The 3-dimensional absorption dose distribution image of bone metastases and targeted organs showed that the dose distribution in bone metastases was not asymmetrical.After injection of 0.65×37 MBq/kg 153Sm-EDTMP,the highest absorption dose in bone lesions was about 4.9–5.9 Gy,and the dose in the lesion margin was about 2.0 Gy.Using the highest dose as reference dose point,the relative absorption dose values of bone marrow,vertebra and sex organ near lesions were 0.48–1.1 Gy,0.51–0.85 Gy,and 0.01–0.14 Gy,respectively.Conclusion:The absorption dose of bone metastases is significantly lower than treatment dose of 30 Gy after single irradiation of 153Sm-EDTMP.The painkilling effect is limited and in accordance with clinical observation.
基金Supported by the Presidential Special Award Foundation, the Chinese Academy of Sciences (Grant No. O7R70020SD)the National Key Technology R & D Program (Grant No. 2006BAC08B0408)
文摘Bouchet in 1963 hypothesized that for large homogeneous land surface with minimum advection of heat and moisture,there exists a 1:1 complementary relationship of potential and actual evaporation coupled through land-atmosphere feedbacks.The complementary relationship has been widely used to estimate regional actual evaporation and explain the pan evaporation paradox.We examine the standardized potential evaporation(potential evaporation divided by wet environment evaporation) at 102 observatories at different elevations across China.Generally,the relationship is appropriate at the low elevations(<1000 m).With the increase of elevation,vapor transfer power becomes much less than radiation energy budget because of lower vapor pressure deficit and stronger global solar radiation.As a result,at the high elevations(over 1000 m),the excess energy resulted by limited moisture availability is not enough to be converted into drying power of the air.This result suggests that the complementary relationship is asymmetric at the high elevations.
基金Supported by the National Natural Science Foundation of China (Grant No. 50509011)the Major State Basic Research Development Program of China (973 Program) (Grant No.2006CB403405)
文摘In the complementary relationship (CR) between actual and potential evapotranspiration, wet envi- ronment evapotranspiration (Ew) is usually calculated using the Priestley-Taylor (P-T) equation. Based on the data obtained from 38 catchments of the Haihe River basin and the Weishan experiment site in Shandong Province of China, this study has found variations in the Priestley-Taylor parameter α (e.g. increase in values with increase in the amount of precipitation on annual scale, seasonal fluctuation noted to be at a maximum during winter and at a minimum during summer, and increased values in the forenoon and decreased values in the afternoon on an hourly scale). This paper explains that the in- ter-annual variation in α is due to the negative feedback of atmosphere in response to changes in ac- tual increase in evapotranspiration, which is weakened because the atmosphere system is open. The parameter α undergoes a seasonal fluctuation brought about by seasonal changes in advection be- tween continent and ocean; α likewise undergoes a daily variation as a result of atmospheric hysteresis in response to the changes in land surface energy.
基金Supported by the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX23_0082)
文摘Breast cancer is presently one of the most common malignancies worldwide,with a higher fatality rate.In this study,a quantitative structure-activity relationship(QSAR)model of compound biological activity and ADMET(Absorption,Distribution,Metabolism,Excretion,Toxicity)properties prediction model were performed using estrogen receptor alpha(ERα)antagonist information collected from compound samples.We first utilized grey relation analysis(GRA)in conjunction with the random forest(RF)algorithm to identify the top 20 molecular descriptor variables that have the greatest influence on biological activity,and then we used Spearman correlation analysis to identify 16 independent variables.Second,a QSAR model of the compound were developed based on BP neural network(BPNN),genetic algorithm optimized BP neural network(GA-BPNN),and support vector regression(SVR).The BPNN,the SVR,and the logistic regression(LR)models were then used to identify and predict the ADMET properties of substances,with the prediction impacts of each model compared and assessed.The results reveal that a SVR model was used in QSAR quantitative prediction,and in the classification prediction of ADMET properties:the SVR model predicts the Caco-2 and hERG(human Ether-a-go-go Related Gene)properties,the LR model predicts the cytochrome P450 enzyme 3A4 subtype(CYP3A4)and Micronucleus(MN)properties,and the BPNN model predicts the Human Oral Bioavailability(HOB)properties.Finally,information entropy theory is used to validate the rationality of variable screening,and sensitivity analysis of the model demonstrates that the constructed model has high accuracy and stability,which can be used as a reference for screening probable active compounds and drug discovery.
