The capture zones of the continuous and pulsed guidance laws in the pursuit-evasion game are analytically discussed in this paper to provide deep insights into the capturability distinction between the continuous guid...The capture zones of the continuous and pulsed guidance laws in the pursuit-evasion game are analytically discussed in this paper to provide deep insights into the capturability distinction between the continuous guidance law and the pulsed guidance law.Specifically,first,in the pursuit-evasion game,various capture cases are defined regarding the Zero-Effort Miss distance(ZEM)to facilitate the capturability analysis.Then,for both the evader and the pursuer,the Linear-Quadratic Differential Game(LQDG)guidance laws concerning the continuous acceleration and the pulsed acceleration are converted into a unified form.In each capture case,the optimal solution existence conditions are derived,and the corresponding capture zones are formulated.The discussion on the capture zones shows that if the optimal solution exists,the distinction between the pulsed guidance law and the continuous guidance law can be neglected under small guidance effort weight.However,the capture zone of the continuous guidance law is larger than that of the pulsed guidance law with large pursuer guidance effort weight,but smaller with large evader guidance effort weight.Finally,various simulations are conducted to illustrate the distinction of the continuous and pulsed guidance laws,as well as the impact of the acceleration ratio and the time constant ratio on the capturability.展开更多
Water-salt balance is critical for the stable coexistence of salt-affected and groundwater-fed oasis-desert ecosystems. Yet, a comprehensive investigation of how soil salinization and groundwater degradation threaten ...Water-salt balance is critical for the stable coexistence of salt-affected and groundwater-fed oasis-desert ecosystems. Yet, a comprehensive investigation of how soil salinization and groundwater degradation threaten the coexistence of oasis-desert ecosystems is still scarce, especially under the compounding effects of human activities and climatic changes. Here, we assessed the impacts of irrigated agriculture on hydrological regimes in oasisdesert systems, investigated the spatio-temporal variations of soil salinization in irrigated cropland, and evaluated the implications of the interplays of soil salinization and groundwater degradation on the coexistence of oasis-desert ecosystems in northwestern China, based on meaningful modelling approaches and comprehensive measurements over 1995–2020. The results showed that the irrigation return flow coefficient decreased sharply from 0.21 ± 0.09 in the traditional irrigation period to 0.09 ± 0.01 in the water-saving irrigation period. The continuous drop in groundwater tables and significant degradation of groundwater quality are occurring throughout this watershed. The eco-environmental flows are reaching to their limit with watershed closures(i.e.,the drainage from the oasis region into the desert region is being weakened or even eliminated), although these progressions were largely hidden by regional precipitation and streamflow variability. The process of salt migration and accumulation across different landscapes in oasis-desert system is being reshaped, and soil salinization in water-saving agricultural irrigated lands is accelerating with a regional average annual growth rate of18%. The vegetation in this watershed is degrading, and anthropogenic disturbance accelerates this trend. Our results highlight that environmental stress adaptation strategies must account for resilience maintenance to avoid accelerating catastrophic transitions in oasis-desert ecosystems. Determining the optimal oasis scales and formulating the best irrigation management plans are effective and resilient decision-making ways to maintain the coexistence relationship of oasis-desert ecosystem in drylands.展开更多
A challenge for the development of Land Surface Models(LSMs) is improving transpiration of water exchange and photosynthesis of carbon exchange between terrestrial plants and the atmosphere, both of which are governed...A challenge for the development of Land Surface Models(LSMs) is improving transpiration of water exchange and photosynthesis of carbon exchange between terrestrial plants and the atmosphere, both of which are governed by stoma in leaves. In the photosynthesis module of these LSMs, variations of parameters arising from diversity in plant functional types(PFTs) and climate remain unclear. Identifying sensitive parameters among all photosynthetic parameters before parameter estimation can not only reduce operation cost, but also improve the usability of photosynthesis models worldwide. Here, we analyzed 13 parameters of a biochemically-based photosynthesis model(FvCB), implemented in many LSMs, using two sensitivity analysis(SA) methods(i.e., the Sobol’ method and the Morris method) for setting up the parameter ensemble. Three different model performance metrics, i.e.,Root Mean Squared Error(RMSE), Nash Sutcliffe efficiency(NSE), and Standard Deviation(STDEV) were introduced for model assessment and sensitive parameters identification. The results showed that among all photosynthetic parameters only a small portion of parameters were sensitive, and the sensitive parameters were different across plant functional types: maximum rate of Rubisco activity(Vcmax25), maximum electron transport rate(Jmax25), triose phosphate use rate(TPU) and dark respiration in light(Rd) were sensitive in broad leafevergreen trees(BET), broad leaf-deciduous trees(BDT) and needle leaf-evergreen trees(NET), while only Vcmax25and TPU are sensitive in short vegetation(SV), dwarf trees and shrubs(DTS), and agriculture and grassland(AG). The two sensitivity analysis methods suggested a strong SA coherence;in contrast, different model performance metrics led to different SA results. This misfit suggests that more accurate values of sensitive parameters, specifically, species specific and seasonal variable parameters, are required to improve the performance of the FvCB model.展开更多
Coronary-pulmonary artery fistula(CPAF)is a relatively rare type of congenital coronary artery variation,which is mostly asymptomatic and is discovered incidentally by coronary artery CT imaging or angiography.However...Coronary-pulmonary artery fistula(CPAF)is a relatively rare type of congenital coronary artery variation,which is mostly asymptomatic and is discovered incidentally by coronary artery CT imaging or angiography.However,CPAF can cause a phenomenon of inter-artery steal and hemodynamic disorders,leading to myocardial ischemia,arrhythmia,heart failure,syncope and even cardiac sudden death in severe cases.Here we reported a case of a 53-year-old female who complained of intermittent palpitations and had a history of paroxysmal atrial fibrillation.The coronary angiography revealed bilateral coronary artery fistulae to pulmonary artery.In this case,the multiple fistulas were very rare and significant.Multidisciplinary treatment should be considered,including cardiologists,surgeons,anesthesiologists and nurses,etc.Regular follow-up is essential for long-term disease management after diagnosis or surgery.展开更多
Coronary artery anomalies are a kind of rare congenital coronary disease most of which are nonmalignant and asymptomatic,while some could lead to severe clinical manifestations and even sudden cardiac death.Here,we re...Coronary artery anomalies are a kind of rare congenital coronary disease most of which are nonmalignant and asymptomatic,while some could lead to severe clinical manifestations and even sudden cardiac death.Here,we reported an atypical anomaly of a double right coronary artery with no obvious atherosclerosis on angiograms,in a 51-year-old woman who showed mild symptoms and had ischemic signs on electrocardiogram.This anomaly is neither similar to the typical appearances of a split right coronary artery nor a large right ventricle branch,is probably account for the potential risk of myocardial ischemia and highly likely to be missed during coronary angiography.展开更多
Cre-loxP recombination system is widely used in gene function research to realize specific gene knockout or knockin through DNA editing.TheαMHC-MerCreMer transgenic mouse line can achieve conditional cardiomyocyte-sp...Cre-loxP recombination system is widely used in gene function research to realize specific gene knockout or knockin through DNA editing.TheαMHC-MerCreMer transgenic mouse line can achieve conditional cardiomyocyte-specific gene editing and make itself be of high value in cardiovascular research.However,there is an ongoing controversy on cardiomyopathy caused by unspecific Cre activity or related to tamoxifen overload,and the majority of studies only focused on male mice.Here,we investigated in femaleαMHC-MerCreMer mice the effect of tamoxifen on myocardia at a conventional dose of 20 mg/kg for five consecutive days by intraperitoneal injection.Our results confirmed that the conventional dose of tamoxifen administration effectively knock down myocardial MED1 expression within one week,without any changes in body weight or heart and liver mass after a 2-week washout period.Serological examination showed that tamoxifen did not deteriorate hepatic or renal function.Hematoxylin-eosin and Sirius red staining revealed no difference in the structure or fibrosis deposition in the heart upon tamoxifen treatment.F4/80 immunohistochemistry staining showed no signs of increased macrophage infiltration in myocardia.The results of RT-qPCR also confirmed the histological observations.Furthermore,differences in energy metabolism and inflammatory response were observed in femaleαMHC-MerCreMer mice,and the underlying mechanism still needs to be clarified.展开更多
基金co-supported by the National Natural Science Foundation of China(Nos.U24B20157,62203031)the Natural Science Foundation of Beijing Municipality,China(No.4242041)+2 种基金the Natural Science Foundation of Zhejiang Province,China(No.LY24F030002)the Aeronautical ScienceFoundation of China(No.2024Z066051001)the Fundamental Research Funds for the Central Universities of China。
文摘The capture zones of the continuous and pulsed guidance laws in the pursuit-evasion game are analytically discussed in this paper to provide deep insights into the capturability distinction between the continuous guidance law and the pulsed guidance law.Specifically,first,in the pursuit-evasion game,various capture cases are defined regarding the Zero-Effort Miss distance(ZEM)to facilitate the capturability analysis.Then,for both the evader and the pursuer,the Linear-Quadratic Differential Game(LQDG)guidance laws concerning the continuous acceleration and the pulsed acceleration are converted into a unified form.In each capture case,the optimal solution existence conditions are derived,and the corresponding capture zones are formulated.The discussion on the capture zones shows that if the optimal solution exists,the distinction between the pulsed guidance law and the continuous guidance law can be neglected under small guidance effort weight.However,the capture zone of the continuous guidance law is larger than that of the pulsed guidance law with large pursuer guidance effort weight,but smaller with large evader guidance effort weight.Finally,various simulations are conducted to illustrate the distinction of the continuous and pulsed guidance laws,as well as the impact of the acceleration ratio and the time constant ratio on the capturability.
基金supported by the National Key R&D Program of China(2022YFF1303301)the National Natural Science Foundation of China(52179026,42101115,41901100,32301671)+1 种基金the China Postdoctoral Science Foundation Project(2022M720162)the XPCC Science and Technique Foundation(2021AB021).
文摘Water-salt balance is critical for the stable coexistence of salt-affected and groundwater-fed oasis-desert ecosystems. Yet, a comprehensive investigation of how soil salinization and groundwater degradation threaten the coexistence of oasis-desert ecosystems is still scarce, especially under the compounding effects of human activities and climatic changes. Here, we assessed the impacts of irrigated agriculture on hydrological regimes in oasisdesert systems, investigated the spatio-temporal variations of soil salinization in irrigated cropland, and evaluated the implications of the interplays of soil salinization and groundwater degradation on the coexistence of oasis-desert ecosystems in northwestern China, based on meaningful modelling approaches and comprehensive measurements over 1995–2020. The results showed that the irrigation return flow coefficient decreased sharply from 0.21 ± 0.09 in the traditional irrigation period to 0.09 ± 0.01 in the water-saving irrigation period. The continuous drop in groundwater tables and significant degradation of groundwater quality are occurring throughout this watershed. The eco-environmental flows are reaching to their limit with watershed closures(i.e.,the drainage from the oasis region into the desert region is being weakened or even eliminated), although these progressions were largely hidden by regional precipitation and streamflow variability. The process of salt migration and accumulation across different landscapes in oasis-desert system is being reshaped, and soil salinization in water-saving agricultural irrigated lands is accelerating with a regional average annual growth rate of18%. The vegetation in this watershed is degrading, and anthropogenic disturbance accelerates this trend. Our results highlight that environmental stress adaptation strategies must account for resilience maintenance to avoid accelerating catastrophic transitions in oasis-desert ecosystems. Determining the optimal oasis scales and formulating the best irrigation management plans are effective and resilient decision-making ways to maintain the coexistence relationship of oasis-desert ecosystem in drylands.
基金supported by the CAS"Light of West China"Program (No.[2020]82)Key technology projects of Inner Mongolia Autonomous Region (Grant No.2020GG0306)+1 种基金Science and Technology Plan Projects of Alxa League (Grant No.AMY2020-18)Natural Science Foundation of Gansu Province (No.21JR7RA038).
文摘A challenge for the development of Land Surface Models(LSMs) is improving transpiration of water exchange and photosynthesis of carbon exchange between terrestrial plants and the atmosphere, both of which are governed by stoma in leaves. In the photosynthesis module of these LSMs, variations of parameters arising from diversity in plant functional types(PFTs) and climate remain unclear. Identifying sensitive parameters among all photosynthetic parameters before parameter estimation can not only reduce operation cost, but also improve the usability of photosynthesis models worldwide. Here, we analyzed 13 parameters of a biochemically-based photosynthesis model(FvCB), implemented in many LSMs, using two sensitivity analysis(SA) methods(i.e., the Sobol’ method and the Morris method) for setting up the parameter ensemble. Three different model performance metrics, i.e.,Root Mean Squared Error(RMSE), Nash Sutcliffe efficiency(NSE), and Standard Deviation(STDEV) were introduced for model assessment and sensitive parameters identification. The results showed that among all photosynthetic parameters only a small portion of parameters were sensitive, and the sensitive parameters were different across plant functional types: maximum rate of Rubisco activity(Vcmax25), maximum electron transport rate(Jmax25), triose phosphate use rate(TPU) and dark respiration in light(Rd) were sensitive in broad leafevergreen trees(BET), broad leaf-deciduous trees(BDT) and needle leaf-evergreen trees(NET), while only Vcmax25and TPU are sensitive in short vegetation(SV), dwarf trees and shrubs(DTS), and agriculture and grassland(AG). The two sensitivity analysis methods suggested a strong SA coherence;in contrast, different model performance metrics led to different SA results. This misfit suggests that more accurate values of sensitive parameters, specifically, species specific and seasonal variable parameters, are required to improve the performance of the FvCB model.
基金supported by the National Natural Science Foundation of China(No.82100359,No.81273878).
文摘Coronary-pulmonary artery fistula(CPAF)is a relatively rare type of congenital coronary artery variation,which is mostly asymptomatic and is discovered incidentally by coronary artery CT imaging or angiography.However,CPAF can cause a phenomenon of inter-artery steal and hemodynamic disorders,leading to myocardial ischemia,arrhythmia,heart failure,syncope and even cardiac sudden death in severe cases.Here we reported a case of a 53-year-old female who complained of intermittent palpitations and had a history of paroxysmal atrial fibrillation.The coronary angiography revealed bilateral coronary artery fistulae to pulmonary artery.In this case,the multiple fistulas were very rare and significant.Multidisciplinary treatment should be considered,including cardiologists,surgeons,anesthesiologists and nurses,etc.Regular follow-up is essential for long-term disease management after diagnosis or surgery.
基金This work is supported by the National Science Foundation of China(No.81273878).
文摘Coronary artery anomalies are a kind of rare congenital coronary disease most of which are nonmalignant and asymptomatic,while some could lead to severe clinical manifestations and even sudden cardiac death.Here,we reported an atypical anomaly of a double right coronary artery with no obvious atherosclerosis on angiograms,in a 51-year-old woman who showed mild symptoms and had ischemic signs on electrocardiogram.This anomaly is neither similar to the typical appearances of a split right coronary artery nor a large right ventricle branch,is probably account for the potential risk of myocardial ischemia and highly likely to be missed during coronary angiography.
基金the National Natural Science Foundation of China(No.81273878).
文摘Cre-loxP recombination system is widely used in gene function research to realize specific gene knockout or knockin through DNA editing.TheαMHC-MerCreMer transgenic mouse line can achieve conditional cardiomyocyte-specific gene editing and make itself be of high value in cardiovascular research.However,there is an ongoing controversy on cardiomyopathy caused by unspecific Cre activity or related to tamoxifen overload,and the majority of studies only focused on male mice.Here,we investigated in femaleαMHC-MerCreMer mice the effect of tamoxifen on myocardia at a conventional dose of 20 mg/kg for five consecutive days by intraperitoneal injection.Our results confirmed that the conventional dose of tamoxifen administration effectively knock down myocardial MED1 expression within one week,without any changes in body weight or heart and liver mass after a 2-week washout period.Serological examination showed that tamoxifen did not deteriorate hepatic or renal function.Hematoxylin-eosin and Sirius red staining revealed no difference in the structure or fibrosis deposition in the heart upon tamoxifen treatment.F4/80 immunohistochemistry staining showed no signs of increased macrophage infiltration in myocardia.The results of RT-qPCR also confirmed the histological observations.Furthermore,differences in energy metabolism and inflammatory response were observed in femaleαMHC-MerCreMer mice,and the underlying mechanism still needs to be clarified.
