When multiphysics coupling calculations contain time-dependent Monte Carlo particle transport simulations, these simulations often account for the largest part of the calculation time, which is insufferable in certain...When multiphysics coupling calculations contain time-dependent Monte Carlo particle transport simulations, these simulations often account for the largest part of the calculation time, which is insufferable in certain important cases. This study proposes an adaptive strategy for automatically adjusting the sample size to fulfil more reasonable simulations. This is realized based on an extension of the Shannon entropy concept and is essentially different from the popular methods in timeindependent Monte Carlo particle transport simulations, such as controlling the sample size according to the relative error of a target tally or by experience. The results of the two models show that this strategy can yield almost similar results while significantly reducing the calculation time. Considering the efficiency, the sample size should not be increased blindly if the efficiency cannot be enhanced further. The strategy proposed herein satisfies this requirement.展开更多
This paper presents an adaptive strategy called K-locking algorithm for concurrency control in database system.The algorithm integrates an optimistic approach with the K-lock mechanism to control the degree of transac...This paper presents an adaptive strategy called K-locking algorithm for concurrency control in database system.The algorithm integrates an optimistic approach with the K-lock mechanism to control the degree of transaction interference.It is shown that the K-locking strategy is adaptive to the changes in transaction parameters and outperforms both an optimistic approach and a pessimistic approach.展开更多
Collecting statistics is a time-and resource-consuming operation in database systems.It is even more challenging to efficiently collect statistics without affecting system performance,meanwhile keeping correctness in ...Collecting statistics is a time-and resource-consuming operation in database systems.It is even more challenging to efficiently collect statistics without affecting system performance,meanwhile keeping correctness in distributed database.Traditional strategies usually consider one dimension during collecting statistics,which is lack of adaptiveness.In this paper,we propose an adaptive strategy for statistics collecting(ASC),which well balances collecting efficiency,correctness of statistics and effect to system performance.We formally define the procedure of collecting statistics and abstract the relationships among collecting efficiency,correctness of statistics and effect to system performance,and introduce an elastic structure(ESI)storing necessary information generated during proceeding our strategy.ASC can pick appropriate time to trigger collecting action and filter unnecessary tasks,meanwhile reasonably allocating collecting tasks to appropriate executing locations with right executing models through the information stored at ESI.We implement and evaluate our strategy in a distributed database.Experiments show that our solutions generally improve the efficiency and correctness of collecting statistics,moreover,reduce the negative effect to system performance comparing with other strategies.展开更多
Nest site selection is a vital component of bird reproduction success,and an adaptive behavior conducted to decrease nest predation risk with avoiding external disturbances.Understanding patterns of nest site selectio...Nest site selection is a vital component of bird reproduction success,and an adaptive behavior conducted to decrease nest predation risk with avoiding external disturbances.Understanding patterns of nest site selection can provide insights into how species adapt to changes in their habitat and has important conservation implications.In this study,we used microhabitat variables and multi-scale data with a field survey of nest occurrence to determine nest site selection patterns and adaptive strategies of the breeding Oriental Storks(Ciconia boyciana)in different nest areas.Results demonstrate that the nest site microhabitat characteristics of the breeding Oriental Storks significantly differed among the three nesting areas,and nest height was higher in the middle and lower Yangtze River floodplain than in the Northeast China and Bohai Bay nest areas.The food resources and intensity of human disturbance had the greatest effects on the nest site selection of the breeding Oriental Storks.The intensity of human disturbance was positively correlated with the nest height of the breeding Oriental Storks in Bohai Bay and the middle and lower Yangtze River floodplain;however,nest height decreased with the abundance of food resources in the Northeast China nest area.Our findings indicate that the nest site selection patterns of Oriental Storks showed flexible adaptive strategies.In safer environments,nests were lower and closer to food resources,which allows parent storks to invest more in the nestlings.However,in areas where human activity was intense,nests were higher to ensure the safety of their offspring.Some measures that could be taken to improve the breeding habitat of Oriental Storks include increasing the percentage of wetland areas in nesting areas to enhance food resources availability and setting artificial nests at suitable heights in potential nesting grounds to encourage nesting.Finally,the establishment of soft barriers around the nesting areas could increase the safety of nests.展开更多
This article examines the effects of climate change on archaeological sites, using as a case study the archaeological site of Ancient Messene in Greece, and proposes an integrated adaptation strategy. In order to dete...This article examines the effects of climate change on archaeological sites, using as a case study the archaeological site of Ancient Messene in Greece, and proposes an integrated adaptation strategy. In order to determine the site’s most significant risks, a climate data analysis was conducted, taking into account three different climate emission scenarios (Representative Concentration Pathways) and two future periods (2031-2060, 2071-2100). The Intergovernmental Panel on Climate Change (IPCC) vulnerability assessment methodology was adopted to assess the vulnerability of the archaeological site to the effects of climate change. This is the first time such a methodology has been followed in Greece. The analysis revealed that the site’s critical hazards are fire, desertification, and flooding. The geographical location of the site in an intensely dry microclimate and the lack of safe and functional electromechanical and road infrastructure increase its vulnerability. The materials of the monuments are indirectly and directly impacted by climate change, whereas the vegetation is negatively impacted by the frequency of extreme events, especially wildfires. Based on the analysis results, a five-axis adaptation strategy was developed.展开更多
Background:With the expansion of urban areas,the remnants of forested areas play a crucial role in preserving biodiversity in urban environments.This study aimed to explore the impact of spatiotemporal urban expansion...Background:With the expansion of urban areas,the remnants of forested areas play a crucial role in preserving biodiversity in urban environments.This study aimed to explore the impact of spatiotemporal urban expansion on the networks of leaf traits in woody plants within remnant forest patches,thereby enhancing our understanding of plant adaptive strategies and contributing to the conservation of urban biodiversity.Methods:Our study examined woody plants within 120 sample plots across 15 remnant forest patches in Guiyang,China.We constructed leaf trait networks (LTNs) based on 26 anatomical,structural,and compositional leaf traits and assessed the effects of the spatiotemporal dynamics of urban expansion on these LTNs.Results and conclusions:Our results indicate that shrubs within these patches have greater average path lengths and diameters than trees.With increasing urban expansion intensity,we observed a rise in the edge density of the LTN-shrubs.Additionally,modularity within the networks of shrubs decreased as road density and urban expansion intensity increased,and increases in the average path length and average clustering coefficient for shrubs were observed with a rise in the composite terrain complexity index.Notably,patches subjected to‘leapfrog’expansion exhibited greater average patch length and diameter than those experiencing edge growth.Stomatal traits were found to have high degree centrality within these networks,signifying their substantial contribution to multiple functions.In urban remnant forests,shrubs bolster their resilience to variable environmental pressures by augmenting the complexity of their leaf trait networks.展开更多
Climate change studies are diverse with no single study giving a comprehensive review of climate change impacts,adaptation strategies,and policy development in West Africa.The unavailability of an all-inclusive study ...Climate change studies are diverse with no single study giving a comprehensive review of climate change impacts,adaptation strategies,and policy development in West Africa.The unavailability of an all-inclusive study to serve as a guide for practitioners affects the effectiveness of climate change adaptation strategies proposed and adopted in the West African sub-region.The purpose of this study was to review the impacts of climate change risks on the crop,fishery,and livestock sectors,as well as the climate change adaptation strategies and climate-related policies aimed at helping to build resilient agricultural production systems in West Africa.The review process followed a series of rigorous stages until the final selection of 56 articles published from 2009 to 2023.Generally,the results highlighted the adverse effects of climate change risks on food security.We found a continuous decline in food crop production.Additionally,the livestock sector experienced morbidity and mortality,as well as reduction in meat and milk production.The fishery sector recorded loss of fingerlings,reduction in fish stocks,and destruction of mariculture and aquaculture.In West Africa,climate-smart agriculture technologies,physical protection of fishing,and inclusion of gender perspectives in programs appear to be the major adaptation strategies.The study therefore recommends the inclusion of ecosystem and biodiversity restoration,weather insurance,replacement of unsafe vessels,and strengthening gender equality in all climate change mitigation programs,as these will help to secure enough food for present and future generations.展开更多
Crop and livestock production is critical to food security in The Gambia. Over the years, the country has experienced a reduced yield due to perceived climate change events with limited studies on how climate change a...Crop and livestock production is critical to food security in The Gambia. Over the years, the country has experienced a reduced yield due to perceived climate change events with limited studies on how climate change and pollution affect crop production. This study assesses farmers’ knowledge and perceptions of the effects of climate variability and pollution on crop production and their varying adaptation strategies in The Gambia. Both quantitative and qualitative methods were used in this study. The sample size for quantitative data collection was calculated as 432 while the qualitative data involves both the focus group discussions and key informant interviews. The focus group discussions comprised two districts in each of the six agricultural regions and two farming communities engaged in crop production were chosen from each district. Furthermore, eight key informant interviews from relevant institutions were conducted. The study shows that The Gambia is highly vulnerable to extreme climatic events. Although most farmers opined that agricultural land contamination emanates from farm runoff and indiscriminate waste dumping, they had little knowledge of heavy metal pollution and bioremediation. The results showed that farmers experienced constraints such as inadequate access to credit, water, and irrigation facilities, insufficient access to efficient inputs, salt intrusion, etc. which threatened food security. The study concludes that crop farmers acknowledged the existence and impacts of climate change, and therefore recommend the availability and affordability of climate change resilient crops and promote variability awareness campaigns to address climate change impacts in The Gambia.展开更多
This paper presents an adaptive rationalized Haar function approximation method to obtain the optimal injection strategy for alkali-surfactant-polymer(ASP) flooding. In this process, the non-uniform control vector par...This paper presents an adaptive rationalized Haar function approximation method to obtain the optimal injection strategy for alkali-surfactant-polymer(ASP) flooding. In this process, the non-uniform control vector parameterization is introduced to convert original problem into a multistage optimization problem, in which a new normalized time variable is adopted on the combination of the subinterval length. Then the rationalized Haar function approximation method, in which an auxiliary function is introduced to dispose path constraints, is used to transform the multistage problem into a nonlinear programming. Furthermore, an adaptive strategy proposed on the basis of errors is adopted to regulate the order of Haar function vectors. Finally, the nonlinear programming for ASP flooding is solved by sequential quadratic programming. To illustrate the performance of proposed method,the experimental comparison method and control vector parameterization(CVP) method are introduced to optimize the original problem directly. By contrastive analysis of results, the accuracy and efficiency of proposed method are confirmed.展开更多
[Objective] The aim was to test the reliability and validity of questionnaire on the adaptation strategy of cryosphere changes in arid inland river basin. [Method] A questionnaire on 'the adaptation strategy of cr...[Objective] The aim was to test the reliability and validity of questionnaire on the adaptation strategy of cryosphere changes in arid inland river basin. [Method] A questionnaire on 'the adaptation strategy of cryosphere changes in arid inland river basin' was carried out in Urumchi River basin and Aksu River basin, and its reliability and validity were tested by means of statistical method, so as to investigate the stability and accuracy of questionnaire. [Result] Reliability analysis of questionnaire showed that the split-half reliability coefficient of questionnaire in Urumchi River basin and Aksu River basin was 0.729 and 0.750, respectively, and Cronbach’s α reliability coefficient was 0.613 and 0.616, respectively, which revealed that the questionnaire had good equivalence and internal consistency which reflected good reliability and stability. According to validity analysis on questionnaire, there was significant correlation between the score of most questions and questionnaire, and it indicated that questionnaire had high content validity. There were 8 common factors collected from 26 questions, which were summarized as agricultural planting, agricultural water conservation, life satisfaction, cultivated land variation, social integration sense, climate and cryosphere changes, capital input improved by environment and family economic condition, respectively. Meanwhile, the contribution rate of various questions in corresponding indexes was higher, and reflected structure was in full accord with questionnaire content, which revealed that questionnaire owned good construct validity. [Conclusion] With higher stability and accuracy, the questionnaire could determine the desired topic and content and was suitable for the study on the perception of common people and choices of adaptive strategy under cryosphere changes in arid inland river basin in northwestern China.展开更多
The reliability and reliability sensitivity ( RS ) models are presented for the engineering problem involving truncated correlated normal variables (CNV), and in the case an adaptive radial based sampling is used ...The reliability and reliability sensitivity ( RS ) models are presented for the engineering problem involving truncated correlated normal variables (CNV), and in the case an adaptive radial based sampling is used to analyze the reliability and the RS. In the presented models, the truncated CNV is transformed to general CNV, and the value domains of the truncated CNV are treated as multiple failure modes, then the reliability and the RS with the truncated CNV are transformed to the general cases, on which an e^cient radial based sampling is used to analyze the trans- formed reliability and RS. An adaptive strategy is employed to search for the optimal radial in the sampling, by which the robustness of the method is improved. After the model concepts and the detailed implementation are given, several examples are presented to demonstrate the feasibility of the model and the efficiency of the solutions.展开更多
Farmers’ perceptions, beliefs, adaptive strategies, and barriers regarding climate change are critical to promoting sustainable ecosystems and societal stability. This paper is based on an extensive survey of 1 500 f...Farmers’ perceptions, beliefs, adaptive strategies, and barriers regarding climate change are critical to promoting sustainable ecosystems and societal stability. This paper is based on an extensive survey of 1 500 farmers and their households in Henan Province in China during 2013–2014. Henan is the largest agricultural province in China with over 51 million farmers. The survey results showed that approximately 57% of the respondents perceived the direct impact of climate change during the past 10 years, with 70.3% believing that climate change posed a risk to their livelihood. Not surprisingly, most farmers reported that they have adopted new measures to mitigate the negative impacts of climate change. The main barriers hindering farmers’ adopting adaptation measures were lack of funds and timely information. A multinomial logit model revealed that land ownership, knowledge of crop variety and the causes of climate change, as well as the belief of climate change, were all positively related to the likelihood of employing adaptive strategies. Moreover, the percentage of households engaging in agriculture activity, and years of engaging in farming were both negatively correlated with famer’s likelihood of adopting adaptation strategies. More importantly, farmers with high incomes were less likely to adopt adaptive strategies and more willing to engage in other business activities. In conclusion, it is important to communicate climate change related information and government policies in rural areas, promote farmer associations and other educational outreach efforts to assist Chinese farmers to deal with climate change.展开更多
This paper reviews assessment of climate change impacts on economy, society and ecological environment in the coastal areas of South China based on published literatures; it also proposes suitable adaptation strategie...This paper reviews assessment of climate change impacts on economy, society and ecological environment in the coastal areas of South China based on published literatures; it also proposes suitable adaptation strategies and counter- measures. Review shows that climate change has resulted in sea level rise in the coastal areas of South China, increasing the occurrence and intensity of storm surges, aggravating the influence of saltwater intrusion, coastal erosion, urban drainage and flood control, threatening the coastal facility and infrastructures, inundating lowland areas, offsetting mudflat silting, and degrading mangroves and corm reef ecosystem. Therefore, in order to reduce the adverse effects of climate change and to support the sustainable development in the coastal areas of South China, it is critical to improve the monitoring and early warning system, enhance prevention criteria, fortify coastal protection engineering, strengthen saltwater prevention, and reinforce the ecological restoration and protection.展开更多
It can be seen from the calculation that the vulnerable area along China's coast in which the elevation is less than 5 m, is 143 900 km2, accounting for about 11. 3% of the total area of the 11 coastal provinces, ...It can be seen from the calculation that the vulnerable area along China's coast in which the elevation is less than 5 m, is 143 900 km2, accounting for about 11. 3% of the total area of the 11 coastal provinces, municipalities and autonomous regions. These areas are threatened to varying extent by sea level rise. According to prediction, the relative sea level rise (including global sea level rise caused by climate change and local relative as level rise caused by vertical crust movement and ground subsidence) along China's coast will be 4~16 cm by the year 2030 with the optimum estimated value of 6~14cm. It will be 9~26 cm by the year 2050 with the optimum estimated value of 12-23 cm. And it will be 31-74 cm by the year 2100 with the optimum estimated value of 47~65 cm. The calcuation result shows that the percentage of the cost for up-grading (heightening and consolidating) sea dykes/walls in adaptation strategy in the losses of submerged areas varies from area to area: 6. 9% in the Zhujiang (Pearl) River Deta, 1. 3% ~24. 6% in the Changjiang (Yangtze) River Delta, and 0. 9%~2. 0% in the Huanghe River Delta.展开更多
The worldwide extension and intensification of farming during the last century has led to ecosystem degradation and caused a series of environmental problems.Conservation of ecosystem services in agricultural regions ...The worldwide extension and intensification of farming during the last century has led to ecosystem degradation and caused a series of environmental problems.Conservation of ecosystem services in agricultural regions has been implemented by top-down government actions or initiated by resilience scientists in the developed countries,but little attention was paid in the developing countries,especially in some remote mountainous regions.The present paper presents a case study showing how local farmers obtained both maximal societal outcomes and agroecosystem conservation interests in the absence of distinct boundaries between agricultural and protected ecological areas in the densely populated purple-soiled hilly region of southwestern China.The local community(Yanting County) has developed a mosaic agricultural-forestry-fishery-stock breeding system with spatially targeted land uses,diverse agricultural productions and multiple ecological partnerships.It indicates that the local farmers have hereditarily perceived sound strategies on maximizing sustainable societal outcomes and optimizing tradeoffs among macro-market,state policy,new technological facility and ecological reinforcement.展开更多
Fuel cell hybrid electric vehicles are currently being considered as ideal means to solve the energy crisis and global warming in today’s society.In this context,this paper proposes a method to solve the problem rela...Fuel cell hybrid electric vehicles are currently being considered as ideal means to solve the energy crisis and global warming in today’s society.In this context,this paper proposes a method to solve the problem related to the dependence of the so-called optimal equivalent factor(determined in the framework of the equivalent consumption minimum strategy-ECMS)on the working conditions.The simulation results show that under typical conditions(some representative cities being considered),the proposed strategy can maintain the power balance;for different initial battery’s states of charge(SOC),after the SOC stabilizes,the fuel consumption is 5.25 L/100 km.展开更多
Looking from China’s neighboring environment, the America factor is undoubtedly the most important factor in analyzing China’s neighboring security. Speaking of U. S. influence on China’s neighboring security, some...Looking from China’s neighboring environment, the America factor is undoubtedly the most important factor in analyzing China’s neighboring security. Speaking of U. S. influence on China’s neighboring security, some scholars tend to believe that the unfavorable factors play a dominant role. This conclusion comes from the "new moonshape encirclement" already existing since the Cold War in America,展开更多
Managing severe burns remains problematic due to the lack of specialized units, but also because of the delay in implementing emergency care. The aim is to show that an adapted strategy, can lead to satisfying managem...Managing severe burns remains problematic due to the lack of specialized units, but also because of the delay in implementing emergency care. The aim is to show that an adapted strategy, can lead to satisfying management of chemical burns. The authors report retrospectively the case of a patient admitted for chemical burns, and treated in a non-specialized intensive care unit;a 38 years old male, referred for burns by sulfuric acid at his workplace. On admission to H15, the clinic did not reveal any vital organs failure. Burns were localized on two legs and soles of the two feet (18% TBSA). Treatment combined daily dressings with silver sulfadiazine. On day 14, the wound healing associated occlusive gauze dressing, iodine cream application, and mechanical debridement. On day 47, a 5% dermal autograft performed on right foot favored with good attachment grafts. On day 58, the patient was released after complete skin recovery. Then, in a non-specialized burn unit and without early surgery access, our wound healing adapted strategy was successful. In Senegal, chemical burns represent about 2.5% of burn cases. They are often from accidents on occupation job, while generally in Africa chemical burns result from criminal attacks. Patients with severe lesions are admitted in non-specialized environments after an extended time of transfer, and don’t have efficient initial care. This may explain the high morbidity and mortality after burns in our country. The lack of surgical facilities such as skin substitutes, in non-specialized unit on low or median income countries (LMICs), explains this long period of wound healing. The treatment of severe burn in LMICs is hazardous.展开更多
Economic impact of climate extremes on beef operation is expected to be significant due to its direct impact on feed production. Impact of such events on farm management and longer term farm financial situation is rel...Economic impact of climate extremes on beef operation is expected to be significant due to its direct impact on feed production. Impact of such events on farm management and longer term farm financial situation is relatively unstudied in the Canadian Prairie. This study compared three alternative beef herd management strategies in dealing with climate extreme events under reference climate scenario of 1971-2000 and the future scenario of 2041-2070. The study used farm simulation model that integrated the model of cattle herd simulation, pasture model, crop simulation model combined with models of economic decisions. Purchasing feed and maintaining herd size is preferred option in dealing with drought Changes in management such as early weaning combined with limit feeding strategies reduce the feed demand and also reduce the financial burden during the years of extreme event, but it has severe negative consequences on amount of slaughter cattle sold. Cull herd strategy not only reduces feed demand but also increases income from sell of herd during the year/s of extreme event, but it severely impacts the farm's long term output supply potential. However, expansion of existing agriculture risk management policy to cover climate risk in beef production is necessary to support farmers in the year/s to extreme events.展开更多
In arid and semi-arid sand dune ecosystems,belowground bud bank plays an important role in population regeneration and vegetation restoration.However,the responses of belowground bud bank size and composition to sand ...In arid and semi-arid sand dune ecosystems,belowground bud bank plays an important role in population regeneration and vegetation restoration.However,the responses of belowground bud bank size and composition to sand burial and its induced changes in soil environmental factors have been rarely studied.In arid sand dunes of Northwestern China,we investigated belowground bud bank size and composition of the typical rhizomatous psammophyte Psammochloa villosa as well as three key soil environmental factors(soil moisture,total carbon and total nitrogen)under different depths of sand burial.Total buds and rhizome buds increased significantly with increasing burial depth,whereas tiller buds first increased and then decreased,with a peak value at the depth of 20-30 cm.Soil moisture increased significantly with sand burial depth,and was positively correlated with the number of all buds and rhizome buds.Soil total carbon concentration first increased and then decreased with sand burial depth,and total nitrogen concentration was significantly lower under deep sand burial than those at shallow depths,and only the number of tiller buds was positively correlated with soil total nitrogen concentration.These results indicate that soil moisture rather than soil nutrient might regulate the belowground bud bank of P.villosa,and that clonal psammophytes could regulate their belowground bud bank in response to sand burial and the most important environmental stress(i.e.,soil moisture).These responses,as the key adaptive strategy,may ensure clonal plant population regeneration and vegetation restoration in arid sand dunes.展开更多
基金supported by the CAEP Found (No.CX20200028)Youth Program of National Natural Science Foundation of China (No.11705011).
文摘When multiphysics coupling calculations contain time-dependent Monte Carlo particle transport simulations, these simulations often account for the largest part of the calculation time, which is insufferable in certain important cases. This study proposes an adaptive strategy for automatically adjusting the sample size to fulfil more reasonable simulations. This is realized based on an extension of the Shannon entropy concept and is essentially different from the popular methods in timeindependent Monte Carlo particle transport simulations, such as controlling the sample size according to the relative error of a target tally or by experience. The results of the two models show that this strategy can yield almost similar results while significantly reducing the calculation time. Considering the efficiency, the sample size should not be increased blindly if the efficiency cannot be enhanced further. The strategy proposed herein satisfies this requirement.
文摘This paper presents an adaptive strategy called K-locking algorithm for concurrency control in database system.The algorithm integrates an optimistic approach with the K-lock mechanism to control the degree of transaction interference.It is shown that the K-locking strategy is adaptive to the changes in transaction parameters and outperforms both an optimistic approach and a pessimistic approach.
基金This project was supported by Key Research and Development Program(2018YFB1003403)the National Natural Science Foundation of China(Grant Nos.61732014,61672432,61672434)Natural Science Basic Research Plan in Shaanxi Province of China(2017JM6104).
文摘Collecting statistics is a time-and resource-consuming operation in database systems.It is even more challenging to efficiently collect statistics without affecting system performance,meanwhile keeping correctness in distributed database.Traditional strategies usually consider one dimension during collecting statistics,which is lack of adaptiveness.In this paper,we propose an adaptive strategy for statistics collecting(ASC),which well balances collecting efficiency,correctness of statistics and effect to system performance.We formally define the procedure of collecting statistics and abstract the relationships among collecting efficiency,correctness of statistics and effect to system performance,and introduce an elastic structure(ESI)storing necessary information generated during proceeding our strategy.ASC can pick appropriate time to trigger collecting action and filter unnecessary tasks,meanwhile reasonably allocating collecting tasks to appropriate executing locations with right executing models through the information stored at ESI.We implement and evaluate our strategy in a distributed database.Experiments show that our solutions generally improve the efficiency and correctness of collecting statistics,moreover,reduce the negative effect to system performance comparing with other strategies.
基金supported by the National Natural Science Foundation of China(Grant No.32171530 and 31472020)。
文摘Nest site selection is a vital component of bird reproduction success,and an adaptive behavior conducted to decrease nest predation risk with avoiding external disturbances.Understanding patterns of nest site selection can provide insights into how species adapt to changes in their habitat and has important conservation implications.In this study,we used microhabitat variables and multi-scale data with a field survey of nest occurrence to determine nest site selection patterns and adaptive strategies of the breeding Oriental Storks(Ciconia boyciana)in different nest areas.Results demonstrate that the nest site microhabitat characteristics of the breeding Oriental Storks significantly differed among the three nesting areas,and nest height was higher in the middle and lower Yangtze River floodplain than in the Northeast China and Bohai Bay nest areas.The food resources and intensity of human disturbance had the greatest effects on the nest site selection of the breeding Oriental Storks.The intensity of human disturbance was positively correlated with the nest height of the breeding Oriental Storks in Bohai Bay and the middle and lower Yangtze River floodplain;however,nest height decreased with the abundance of food resources in the Northeast China nest area.Our findings indicate that the nest site selection patterns of Oriental Storks showed flexible adaptive strategies.In safer environments,nests were lower and closer to food resources,which allows parent storks to invest more in the nestlings.However,in areas where human activity was intense,nests were higher to ensure the safety of their offspring.Some measures that could be taken to improve the breeding habitat of Oriental Storks include increasing the percentage of wetland areas in nesting areas to enhance food resources availability and setting artificial nests at suitable heights in potential nesting grounds to encourage nesting.Finally,the establishment of soft barriers around the nesting areas could increase the safety of nests.
文摘This article examines the effects of climate change on archaeological sites, using as a case study the archaeological site of Ancient Messene in Greece, and proposes an integrated adaptation strategy. In order to determine the site’s most significant risks, a climate data analysis was conducted, taking into account three different climate emission scenarios (Representative Concentration Pathways) and two future periods (2031-2060, 2071-2100). The Intergovernmental Panel on Climate Change (IPCC) vulnerability assessment methodology was adopted to assess the vulnerability of the archaeological site to the effects of climate change. This is the first time such a methodology has been followed in Greece. The analysis revealed that the site’s critical hazards are fire, desertification, and flooding. The geographical location of the site in an intensely dry microclimate and the lack of safe and functional electromechanical and road infrastructure increase its vulnerability. The materials of the monuments are indirectly and directly impacted by climate change, whereas the vegetation is negatively impacted by the frequency of extreme events, especially wildfires. Based on the analysis results, a five-axis adaptation strategy was developed.
基金funded by the National Natural Science Foundation of China (No.32360418)the Guizhou Provincial Basic Research Program (Natural Science)(No.QianKeHeJiChu-ZK[2024]YiBan022)。
文摘Background:With the expansion of urban areas,the remnants of forested areas play a crucial role in preserving biodiversity in urban environments.This study aimed to explore the impact of spatiotemporal urban expansion on the networks of leaf traits in woody plants within remnant forest patches,thereby enhancing our understanding of plant adaptive strategies and contributing to the conservation of urban biodiversity.Methods:Our study examined woody plants within 120 sample plots across 15 remnant forest patches in Guiyang,China.We constructed leaf trait networks (LTNs) based on 26 anatomical,structural,and compositional leaf traits and assessed the effects of the spatiotemporal dynamics of urban expansion on these LTNs.Results and conclusions:Our results indicate that shrubs within these patches have greater average path lengths and diameters than trees.With increasing urban expansion intensity,we observed a rise in the edge density of the LTN-shrubs.Additionally,modularity within the networks of shrubs decreased as road density and urban expansion intensity increased,and increases in the average path length and average clustering coefficient for shrubs were observed with a rise in the composite terrain complexity index.Notably,patches subjected to‘leapfrog’expansion exhibited greater average patch length and diameter than those experiencing edge growth.Stomatal traits were found to have high degree centrality within these networks,signifying their substantial contribution to multiple functions.In urban remnant forests,shrubs bolster their resilience to variable environmental pressures by augmenting the complexity of their leaf trait networks.
文摘Climate change studies are diverse with no single study giving a comprehensive review of climate change impacts,adaptation strategies,and policy development in West Africa.The unavailability of an all-inclusive study to serve as a guide for practitioners affects the effectiveness of climate change adaptation strategies proposed and adopted in the West African sub-region.The purpose of this study was to review the impacts of climate change risks on the crop,fishery,and livestock sectors,as well as the climate change adaptation strategies and climate-related policies aimed at helping to build resilient agricultural production systems in West Africa.The review process followed a series of rigorous stages until the final selection of 56 articles published from 2009 to 2023.Generally,the results highlighted the adverse effects of climate change risks on food security.We found a continuous decline in food crop production.Additionally,the livestock sector experienced morbidity and mortality,as well as reduction in meat and milk production.The fishery sector recorded loss of fingerlings,reduction in fish stocks,and destruction of mariculture and aquaculture.In West Africa,climate-smart agriculture technologies,physical protection of fishing,and inclusion of gender perspectives in programs appear to be the major adaptation strategies.The study therefore recommends the inclusion of ecosystem and biodiversity restoration,weather insurance,replacement of unsafe vessels,and strengthening gender equality in all climate change mitigation programs,as these will help to secure enough food for present and future generations.
文摘Crop and livestock production is critical to food security in The Gambia. Over the years, the country has experienced a reduced yield due to perceived climate change events with limited studies on how climate change and pollution affect crop production. This study assesses farmers’ knowledge and perceptions of the effects of climate variability and pollution on crop production and their varying adaptation strategies in The Gambia. Both quantitative and qualitative methods were used in this study. The sample size for quantitative data collection was calculated as 432 while the qualitative data involves both the focus group discussions and key informant interviews. The focus group discussions comprised two districts in each of the six agricultural regions and two farming communities engaged in crop production were chosen from each district. Furthermore, eight key informant interviews from relevant institutions were conducted. The study shows that The Gambia is highly vulnerable to extreme climatic events. Although most farmers opined that agricultural land contamination emanates from farm runoff and indiscriminate waste dumping, they had little knowledge of heavy metal pollution and bioremediation. The results showed that farmers experienced constraints such as inadequate access to credit, water, and irrigation facilities, insufficient access to efficient inputs, salt intrusion, etc. which threatened food security. The study concludes that crop farmers acknowledged the existence and impacts of climate change, and therefore recommend the availability and affordability of climate change resilient crops and promote variability awareness campaigns to address climate change impacts in The Gambia.
基金Supported by the National Natural Science Foundation of China(61573378)the Fundamental Research Funds for the Central Universities(15CX06064A)
文摘This paper presents an adaptive rationalized Haar function approximation method to obtain the optimal injection strategy for alkali-surfactant-polymer(ASP) flooding. In this process, the non-uniform control vector parameterization is introduced to convert original problem into a multistage optimization problem, in which a new normalized time variable is adopted on the combination of the subinterval length. Then the rationalized Haar function approximation method, in which an auxiliary function is introduced to dispose path constraints, is used to transform the multistage problem into a nonlinear programming. Furthermore, an adaptive strategy proposed on the basis of errors is adopted to regulate the order of Haar function vectors. Finally, the nonlinear programming for ASP flooding is solved by sequential quadratic programming. To illustrate the performance of proposed method,the experimental comparison method and control vector parameterization(CVP) method are introduced to optimize the original problem directly. By contrastive analysis of results, the accuracy and efficiency of proposed method are confirmed.
基金Supported by Major State Basic Research Development Program of China(2007CB411507)Open Foundation Project of State Key Laboratory of Cryospheric Sciences,Chinese Academy of Sciences(SKLCS08-04)
文摘[Objective] The aim was to test the reliability and validity of questionnaire on the adaptation strategy of cryosphere changes in arid inland river basin. [Method] A questionnaire on 'the adaptation strategy of cryosphere changes in arid inland river basin' was carried out in Urumchi River basin and Aksu River basin, and its reliability and validity were tested by means of statistical method, so as to investigate the stability and accuracy of questionnaire. [Result] Reliability analysis of questionnaire showed that the split-half reliability coefficient of questionnaire in Urumchi River basin and Aksu River basin was 0.729 and 0.750, respectively, and Cronbach’s α reliability coefficient was 0.613 and 0.616, respectively, which revealed that the questionnaire had good equivalence and internal consistency which reflected good reliability and stability. According to validity analysis on questionnaire, there was significant correlation between the score of most questions and questionnaire, and it indicated that questionnaire had high content validity. There were 8 common factors collected from 26 questions, which were summarized as agricultural planting, agricultural water conservation, life satisfaction, cultivated land variation, social integration sense, climate and cryosphere changes, capital input improved by environment and family economic condition, respectively. Meanwhile, the contribution rate of various questions in corresponding indexes was higher, and reflected structure was in full accord with questionnaire content, which revealed that questionnaire owned good construct validity. [Conclusion] With higher stability and accuracy, the questionnaire could determine the desired topic and content and was suitable for the study on the perception of common people and choices of adaptive strategy under cryosphere changes in arid inland river basin in northwestern China.
基金support of the Natural Science Foundation of China (NSFC10572117and 50875213)Aviation Science Foundation(2007ZA53012)863 Project (2007AA04Z401)
文摘The reliability and reliability sensitivity ( RS ) models are presented for the engineering problem involving truncated correlated normal variables (CNV), and in the case an adaptive radial based sampling is used to analyze the reliability and the RS. In the presented models, the truncated CNV is transformed to general CNV, and the value domains of the truncated CNV are treated as multiple failure modes, then the reliability and the RS with the truncated CNV are transformed to the general cases, on which an e^cient radial based sampling is used to analyze the trans- formed reliability and RS. An adaptive strategy is employed to search for the optimal radial in the sampling, by which the robustness of the method is improved. After the model concepts and the detailed implementation are given, several examples are presented to demonstrate the feasibility of the model and the efficiency of the solutions.
基金supported by the National Natural Science Foundation of China (41301149)the National Major Scientific Research Project, China (2012CB955800)+3 种基金the China Postdoctoral Science Foundation of the Fifty-Seventh Batch of Funds (2015M570626)the Open Research Fund of the Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions, Ministry of Education, China (JOF 201601)the Open Research Funding Program of Key Laboratory of Geographic Information Science, Ministry of Education (KLGIS2014A03)the Science and Technology Innovation Team Support Plan Funded for University in Henan Province, China (16IRTSTHN012)
文摘Farmers’ perceptions, beliefs, adaptive strategies, and barriers regarding climate change are critical to promoting sustainable ecosystems and societal stability. This paper is based on an extensive survey of 1 500 farmers and their households in Henan Province in China during 2013–2014. Henan is the largest agricultural province in China with over 51 million farmers. The survey results showed that approximately 57% of the respondents perceived the direct impact of climate change during the past 10 years, with 70.3% believing that climate change posed a risk to their livelihood. Not surprisingly, most farmers reported that they have adopted new measures to mitigate the negative impacts of climate change. The main barriers hindering farmers’ adopting adaptation measures were lack of funds and timely information. A multinomial logit model revealed that land ownership, knowledge of crop variety and the causes of climate change, as well as the belief of climate change, were all positively related to the likelihood of employing adaptive strategies. Moreover, the percentage of households engaging in agriculture activity, and years of engaging in farming were both negatively correlated with famer’s likelihood of adopting adaptation strategies. More importantly, farmers with high incomes were less likely to adopt adaptive strategies and more willing to engage in other business activities. In conclusion, it is important to communicate climate change related information and government policies in rural areas, promote farmer associations and other educational outreach efforts to assist Chinese farmers to deal with climate change.
基金supported by the Special Climate Change Research Program of China Meteorological Administration(No.CCSF-09-11,CCSF2011-25,and CCSF201307)the Science and Technology Planning Project of Guangdong Province(No.2011A030200021)
文摘This paper reviews assessment of climate change impacts on economy, society and ecological environment in the coastal areas of South China based on published literatures; it also proposes suitable adaptation strategies and counter- measures. Review shows that climate change has resulted in sea level rise in the coastal areas of South China, increasing the occurrence and intensity of storm surges, aggravating the influence of saltwater intrusion, coastal erosion, urban drainage and flood control, threatening the coastal facility and infrastructures, inundating lowland areas, offsetting mudflat silting, and degrading mangroves and corm reef ecosystem. Therefore, in order to reduce the adverse effects of climate change and to support the sustainable development in the coastal areas of South China, it is critical to improve the monitoring and early warning system, enhance prevention criteria, fortify coastal protection engineering, strengthen saltwater prevention, and reinforce the ecological restoration and protection.
文摘It can be seen from the calculation that the vulnerable area along China's coast in which the elevation is less than 5 m, is 143 900 km2, accounting for about 11. 3% of the total area of the 11 coastal provinces, municipalities and autonomous regions. These areas are threatened to varying extent by sea level rise. According to prediction, the relative sea level rise (including global sea level rise caused by climate change and local relative as level rise caused by vertical crust movement and ground subsidence) along China's coast will be 4~16 cm by the year 2030 with the optimum estimated value of 6~14cm. It will be 9~26 cm by the year 2050 with the optimum estimated value of 12-23 cm. And it will be 31-74 cm by the year 2100 with the optimum estimated value of 47~65 cm. The calcuation result shows that the percentage of the cost for up-grading (heightening and consolidating) sea dykes/walls in adaptation strategy in the losses of submerged areas varies from area to area: 6. 9% in the Zhujiang (Pearl) River Deta, 1. 3% ~24. 6% in the Changjiang (Yangtze) River Delta, and 0. 9%~2. 0% in the Huanghe River Delta.
基金funded by Ministry of Science and Technology of China (Grant No.2011BAD31B03)Chinese Academy of Sciences(Grant No. KZCX2-XB3-09)Ministry of Environmental Protection of China (Grant No.2009ZX07014-002-06)
文摘The worldwide extension and intensification of farming during the last century has led to ecosystem degradation and caused a series of environmental problems.Conservation of ecosystem services in agricultural regions has been implemented by top-down government actions or initiated by resilience scientists in the developed countries,but little attention was paid in the developing countries,especially in some remote mountainous regions.The present paper presents a case study showing how local farmers obtained both maximal societal outcomes and agroecosystem conservation interests in the absence of distinct boundaries between agricultural and protected ecological areas in the densely populated purple-soiled hilly region of southwestern China.The local community(Yanting County) has developed a mosaic agricultural-forestry-fishery-stock breeding system with spatially targeted land uses,diverse agricultural productions and multiple ecological partnerships.It indicates that the local farmers have hereditarily perceived sound strategies on maximizing sustainable societal outcomes and optimizing tradeoffs among macro-market,state policy,new technological facility and ecological reinforcement.
基金This work was supported by the Key Research and Development Program of Shandong Province(Grant No.2019JZZY010912)the Key Research and Development Program of Shandong Province(Grant No.2020CXGC010406)。
文摘Fuel cell hybrid electric vehicles are currently being considered as ideal means to solve the energy crisis and global warming in today’s society.In this context,this paper proposes a method to solve the problem related to the dependence of the so-called optimal equivalent factor(determined in the framework of the equivalent consumption minimum strategy-ECMS)on the working conditions.The simulation results show that under typical conditions(some representative cities being considered),the proposed strategy can maintain the power balance;for different initial battery’s states of charge(SOC),after the SOC stabilizes,the fuel consumption is 5.25 L/100 km.
文摘Looking from China’s neighboring environment, the America factor is undoubtedly the most important factor in analyzing China’s neighboring security. Speaking of U. S. influence on China’s neighboring security, some scholars tend to believe that the unfavorable factors play a dominant role. This conclusion comes from the "new moonshape encirclement" already existing since the Cold War in America,
文摘Managing severe burns remains problematic due to the lack of specialized units, but also because of the delay in implementing emergency care. The aim is to show that an adapted strategy, can lead to satisfying management of chemical burns. The authors report retrospectively the case of a patient admitted for chemical burns, and treated in a non-specialized intensive care unit;a 38 years old male, referred for burns by sulfuric acid at his workplace. On admission to H15, the clinic did not reveal any vital organs failure. Burns were localized on two legs and soles of the two feet (18% TBSA). Treatment combined daily dressings with silver sulfadiazine. On day 14, the wound healing associated occlusive gauze dressing, iodine cream application, and mechanical debridement. On day 47, a 5% dermal autograft performed on right foot favored with good attachment grafts. On day 58, the patient was released after complete skin recovery. Then, in a non-specialized burn unit and without early surgery access, our wound healing adapted strategy was successful. In Senegal, chemical burns represent about 2.5% of burn cases. They are often from accidents on occupation job, while generally in Africa chemical burns result from criminal attacks. Patients with severe lesions are admitted in non-specialized environments after an extended time of transfer, and don’t have efficient initial care. This may explain the high morbidity and mortality after burns in our country. The lack of surgical facilities such as skin substitutes, in non-specialized unit on low or median income countries (LMICs), explains this long period of wound healing. The treatment of severe burn in LMICs is hazardous.
文摘Economic impact of climate extremes on beef operation is expected to be significant due to its direct impact on feed production. Impact of such events on farm management and longer term farm financial situation is relatively unstudied in the Canadian Prairie. This study compared three alternative beef herd management strategies in dealing with climate extreme events under reference climate scenario of 1971-2000 and the future scenario of 2041-2070. The study used farm simulation model that integrated the model of cattle herd simulation, pasture model, crop simulation model combined with models of economic decisions. Purchasing feed and maintaining herd size is preferred option in dealing with drought Changes in management such as early weaning combined with limit feeding strategies reduce the feed demand and also reduce the financial burden during the years of extreme event, but it has severe negative consequences on amount of slaughter cattle sold. Cull herd strategy not only reduces feed demand but also increases income from sell of herd during the year/s of extreme event, but it severely impacts the farm's long term output supply potential. However, expansion of existing agriculture risk management policy to cover climate risk in beef production is necessary to support farmers in the year/s to extreme events.
基金This work was financially supported by the National Natural Science Foundation of China(41877542,41907411).
文摘In arid and semi-arid sand dune ecosystems,belowground bud bank plays an important role in population regeneration and vegetation restoration.However,the responses of belowground bud bank size and composition to sand burial and its induced changes in soil environmental factors have been rarely studied.In arid sand dunes of Northwestern China,we investigated belowground bud bank size and composition of the typical rhizomatous psammophyte Psammochloa villosa as well as three key soil environmental factors(soil moisture,total carbon and total nitrogen)under different depths of sand burial.Total buds and rhizome buds increased significantly with increasing burial depth,whereas tiller buds first increased and then decreased,with a peak value at the depth of 20-30 cm.Soil moisture increased significantly with sand burial depth,and was positively correlated with the number of all buds and rhizome buds.Soil total carbon concentration first increased and then decreased with sand burial depth,and total nitrogen concentration was significantly lower under deep sand burial than those at shallow depths,and only the number of tiller buds was positively correlated with soil total nitrogen concentration.These results indicate that soil moisture rather than soil nutrient might regulate the belowground bud bank of P.villosa,and that clonal psammophytes could regulate their belowground bud bank in response to sand burial and the most important environmental stress(i.e.,soil moisture).These responses,as the key adaptive strategy,may ensure clonal plant population regeneration and vegetation restoration in arid sand dunes.