Climate change is a global issue that poses a significant risk to the global economy and therefore warrants coordinated collective action.Employing a questionnaire survey in China,this study presents urban residents&#...Climate change is a global issue that poses a significant risk to the global economy and therefore warrants coordinated collective action.Employing a questionnaire survey in China,this study presents urban residents'behavioral response to climate change and its influencing factors.The results indicated that urban residents in Tianjin often took low-cost,intuitive,and quickly implementable actions,namely behavioral coping responses.Proactive adaptive behavior was also evident,which involved greater financial investment.Furthermore,according to regression analysis results of urban residents'behavior and its influencing factors,knowledge of climate change manifested a positive correlation with urban residents'behavioral coping response.In contrast,cost manifested a negative correlation with urban residents'proactive adaptive behavior,which was a more complex,costly,and challenging anticipatory action.Knowledge of climate change manifested a positive correlation with both behavioral coping response and proactive adaptive behavior.Finally,recommendations for encouraging beneficial behaviors among urban residents are suggested.展开更多
Throughout evolutionary history,animals are finely tuned to adjust their behaviors corresponding to environmental variations.Behavioral flexibility represents an important component of a species'adaptive capacity ...Throughout evolutionary history,animals are finely tuned to adjust their behaviors corresponding to environmental variations.Behavioral flexibility represents an important component of a species'adaptive capacity in the face of rapid anthropogenetic environmental change,and knowledge of animal behaviors is increasingly recognized in conservation biology.In aquatic ecosystem,variation of water depth is a key factor affecting the availability of food;thus,the foraging behaviors of many waterbirds,especially piscivores.In this study,we compared the foraging behaviors of the Scaly-sided Merganser(Mergus squamatus),an endangered migratory diving duck endemic to East Asia,in habitats with different water depths(Shallow waters:0–40 cm;Deep waters:40–300 cm),using video camera records obtained from the known wintering sites during three winters from 2018 to 2020.Further,the energy expenditure of foraging behavior profile and energy intake based on fish sizes were calculated to study the foraging energetics.In total,200 effective video footages that contained 1086 min with 17,995 behaviors and 163 events of catching fish were recorded.Results showed that:1)time length for fishing(including eye-submerging,head-dipping,diving and food handling)of M.squamatus in shallow waters was significantly more than in deep waters;2)M.squamatuss spent significantly more time for preparing(including vigilance,preening and swimming)in deep waters than in shallow waters;3)the mean catch rate was 0.28 fish/min in shallow waters,which is significantly higher than the value of 0.13 fish/min in deep waters;4)despite the distinct foraging behavior profiles and energy intakes,M.squamatus showed similar energetics in shallow and deep waters.We concluded that M.squamatus is a good example of behavioral flexibility that aligns with expectations of optimal foraging theory,in that it behaves in accordance to resource availability in different environments,resulting in high foraging efficiency.展开更多
The emergence of adventure tourism is indicative of a process of commodification commensurate with the expansive mechanisms of the hospitality industry.The tension between excitement,thrill,and safety is on-going howe...The emergence of adventure tourism is indicative of a process of commodification commensurate with the expansive mechanisms of the hospitality industry.The tension between excitement,thrill,and safety is on-going however and the emergence of climbing walls in urban areas has provided new ways of becoming a climber:It is in the interests of climbing as business to normalise pay-to-climb conditions.Such overt commercial connections are anathema to real climbers;nevertheless the convenience of climbing walls means they are well populated and used.The present study investigates the attitudes and methods of engagement by a group of older climbers who,for the most part,started climbing in their youth before climbing walls were commonplace.A typology of climbing types is presented as a framework for discussion.The methodology is ethnographic and the findings suggest that,despite subscribing to an organic and outdoor adventure climbing ethos in their youth,this group remains active and adventurously inclined as they consider wall-climbing to be making a positive contribution to their present collective identity.展开更多
Thermal comfort is an important factor in hostel buildings when the aim is to maximize the productivity of the students.Due to the extreme weather conditions,achieving thermal comfort in a hostel building in a hot and...Thermal comfort is an important factor in hostel buildings when the aim is to maximize the productivity of the students.Due to the extreme weather conditions,achieving thermal comfort in a hostel building in a hot and humid climate is even more difficult.Studies conducted in naturally ventilated hostel buildings in warm-humid climates involved the influence of outdoor air temperature only up to 34.4℃ and have been conducted in a specific season.In contrast,the Tiruchirappalli climate is characterized by a higher range of environmental variables.Therefore,to understand the thermal comfort conditions and usage of the environmental controls in naturally ventilated hostel buildings at the higher range of the environmental variables,a thermal comfort field study spread over one year was carried out at the National Institute of Technology,Tiruchirappalli,India,in twenty-seven hostel buildings.This study relies on field observation and thermal comfort responses from 2028 questionnaires collected from the students between September 2019 to August 2020.The analysis revealed a neutral temperature of 29.5℃ and a comfort range from 26.1℃ to 32.8℃,indicating a wide range of ther-mal adaptation than suggested by the National Building Code of India and ASHRAE standard 55.The preferred temperature was 27.8℃,indicating that students preferred a cooler environment.Acceptability with sweating conditions extended the upper limit of thermal acceptability from 31.8℃ to 32.4℃.The use of a mosquito net can increase the probability of opening a window.Results indicated that overall behavioral adjustment could extend the comfort limits.The study results would be helpful to develop guidelines and designs for naturally ventilated hostel buildings in warm and humid climates that will contribute to reducing energy demand.展开更多
Advanced traveler information systems （ATIS） can not only improve drivers＇ accessibility to the more accurate route travel time information, but also can improve drivers＇ adaptability to the stochastic network cap...Advanced traveler information systems （ATIS） can not only improve drivers＇ accessibility to the more accurate route travel time information, but also can improve drivers＇ adaptability to the stochastic network capacity degradations. In this paper, a mixed stochastic user equilibrium model was proposed to describe the interactive route choice behaviors between ATIS equipped and unequipped drivers on a degradable transport network. In the proposed model the information accessibility of equipped drivers was reflected by lower degree of uncertainty in their stochastic equilibrium flow distributions, and their behavioral adaptability was captured by multiple equilibrium behaviors over the stochastic network state set. The mixed equilibrium model was formulated as a fixed point problem defined in the mixed route flows, and its solution was achieved by executing an iterative algorithm. Numerical experiments were provided to verify the properties of the mixed network equilibrium model and the efficiency of the iterative algorithm.展开更多
Urbanization has dramatic impacts on natural habitats and such changes may potentially drive local adaptation of urban populations.Behavioral change has been specifically shown to facilitate the fast adaptation of bir...Urbanization has dramatic impacts on natural habitats and such changes may potentially drive local adaptation of urban populations.Behavioral change has been specifically shown to facilitate the fast adaptation of birds to changing environments,but few studies have investigated the genetic mechanisms of this process.Such investigations could provide insights into questions about both evolutionary theory and management of urban populations.In this study,we investigated whether local adaptation has occurred in urban populations of a Neotropical bird species,Coereba flaveola,specifically addressing whether observed behavioral adaptations are correlated to genetic signatures of natural selection.To answer this question,we sampled 24 individuals in urban and rural environments,and searched for selected loci through a genome-scan approach based on RADseq genomic data,generated and assembled using a reference genome for the species.We recovered 46 loci as putative selection outliers,and 30 of them were identified as associated with biological processes possibly related to urban adaptation,such as the regulation of energetic metabolism,regulation of genetic expression,and changes in the immunological system.Moreover,genes involved in the development of the nervous system showed signatures of selection,suggesting a link between behavioral and genetic adaptations.Our findings,in conjunction with similar results in previous studies,support the idea that cities provide a similar selective pressure on urban populations and that behavioral plasticity may be enhanced through genetic changes in urban populations.展开更多
This paper investigates the effect of factors on Farmers Adaptation Behavior in Water Scarcity Conditions in Rural Communities of Sabzevar,Iran.A survey questionnaire was used for collecting data,the study population ...This paper investigates the effect of factors on Farmers Adaptation Behavior in Water Scarcity Conditions in Rural Communities of Sabzevar,Iran.A survey questionnaire was used for collecting data,the study population was 120 farmers in rural Sabzevar County selected based on the Cochran formula.A questionnaire was designed for the target group for the measurement of on farm adaptation behavior in water scarcity conditions.Research models were drawn using structural equation modeling and the relationships between latent variables and indicators.The findings indicate that there is a significant relationship between awareness and adaptation behavior.Meanwhile,there is a significant relationship among network and media on farmer's perception about water scarcity and their activities toward better management of water in the critical condition.There are also significant relationships among perception and awareness with intention however,intention do not effect on adaptation behavior strongly.In other words,even the that means farmers had information about crisis,they are not able to have not operational plans to confront the water scarcity conditions.展开更多
Purpose–This paper aims to explore whether drivers would adapt their behavior when they drive among automated vehicles(AVs)compared to driving among manually driven vehicles(MVs).Understanding behavioral adaptation o...Purpose–This paper aims to explore whether drivers would adapt their behavior when they drive among automated vehicles(AVs)compared to driving among manually driven vehicles(MVs).Understanding behavioral adaptation of drivers when they encounter AVs is crucial for assessing impacts of AVs in mixed-traffic situations.Here,mixed-traffic situations refer to situations where AVs share the roads with existing nonautomated vehicles such as conventional MVs.Design/methodology/approach–A driving simulator study is designed to explore whether such behavioral adaptations exist.Two different driving scenarios were explored on a three-lane highway:driving on the main highway and merging from an on-ramp.For this study,18 research participants were recruited.Findings–Behavioral adaptation can be observed in terms of car-following speed,car-following time gap,number of lane change and overall driving speed.The adaptations are dependent on the driving scenario and whether the surrounding traffic was AVs or MVs.Although significant differences in behavior were found in more than 90%of the research participants,they adapted their behavior differently,and thus,magnitude of the behavioral adaptation remains unclear.Originality/value–The observed behavioral adaptations in this paper were dependent on the driving scenario rather than the time gap between surrounding vehicles.This finding differs from previous studies,which have shown that drivers tend to adapt their behaviors with respect to the surrounding vehicles.Furthermore,the surrounding vehicles in this study are more“free flow’”compared to previous studies with a fixed formation such as platoons.Nevertheless,long-term observations are required to further support this claim.展开更多
Rapid learning in the young of most endothermic animals can be expected to be favored by natural selection because early independence reduces the period of vulnerability.Cases of comparatively slow juvenile developmen...Rapid learning in the young of most endothermic animals can be expected to be favored by natural selection because early independence reduces the period of vulnerability.Cases of comparatively slow juvenile development continue,therefore,to attract scientific attention.In most species of birds,including raptors,the young depend on their parents for some time after fledging for the provisioning of food and for protection while they learn to become nutritionally and otherwise independent.Among raptors,post-fledging dependence periods that exceed 6 months are exclusive to the largest species and these have reproductive cycles that exceed 12 months.By contrast,young of the medium-sized grey falcon Falco hypoleucos have been reported in close company with their parents up to 12 months after fledging,that is,at a time when the adults are expected to breed again.We investigated the occurrence and characteristics of prolonged adult–juvenile association relative to other falcons and similar-sized raptors.We found that the behavioral development of grey falcon young is extremely delayed,and that they even depend nutritionally on their parents for up to 12 months after fledging.We suggest that these 2 distinctive features are,ultimately,adaptations of the grey falcon to its extreme environment,Australia’s arid and semi-arid zone,one of the hottest environments in the world.展开更多
Throughout the progress of epidemic scenarios,individuals in different health classes are expected to have different average daily contact behavior.This contact heterogeneity has been studied in recent adaptive models...Throughout the progress of epidemic scenarios,individuals in different health classes are expected to have different average daily contact behavior.This contact heterogeneity has been studied in recent adaptive models and allows us to capture the inherent differences across health statuses better.Diseases with reinfection bring out more complex scenarios and offer an important application to consider contact disaggregation.Therefore,we developed a nonlinear differential equation model to explore the dynamics of relapse phenomena and contact differences across health statuses.Our incidence rate function is formulated,taking inspiration from recent adaptive algorithms.It incorporates contact behavior for individuals in each health class.We use constant contact rates at each health status for our analytical results and prove conditions for different forward-backward bifurcation scenarios.The relationship between the different contact rates heavily in-fluences these conditions.Numerical examples highlight the effect of temporarily recov-ered individuals and initial conditions on infected population persistence.展开更多
In order to comprehensively study the influence of climate change on economic growth and energy conservation&emission reduction,this paper fi rst uses the non-radial directional distance function(NDDF)to calculate...In order to comprehensively study the influence of climate change on economic growth and energy conservation&emission reduction,this paper fi rst uses the non-radial directional distance function(NDDF)to calculate the city-level green economic efficiency in China during 2003-2016.The causal effect of daily temperature changes on green economic efficiency is then identifi ed to evaluate the economic consequences of climate change.It fi nds that r elative to the 6~12℃temperature benchmark,any decrease or increase in temperature will pose negative influence on green economic efficiency;moreover,such effects are only observed in developed cities,but not signifi cant in less-developed ones.This refl ects that the economic consequences of climate change are“robbing the rich”to some extents,which differs widely from the“pro-poor”conclusion in the majority of literature previously.Subject to the robustness test and with possible competitive explanations excluded,this finding still stands.The mechanism test reveals that temperature rise brings about economic consequences that“rob the rich”by affecting labor productivity,efficiency of energy conservation&emission reduction and execution of environmental regulations by local government.This study brings a different perspective for understanding the economic consequences of climate change and offers empirical basis for identifying responsibilities of local government in climate governance.展开更多
Based on the characteristics of colony emer-gence of artificial organisms,their dynamic interaction with the environment,and the food-chain crucial to the life system,the rules of local activities of artificial organ-...Based on the characteristics of colony emer-gence of artificial organisms,their dynamic interaction with the environment,and the food-chain crucial to the life system,the rules of local activities of artificial organ-isms at different levels are defined.The article proposes an artificial life-based algorithm,which is referred to as the food-chain algorithm.This algorithm optimizes computa-tion by simulating the evolution of natural ecosystems and the information processing mechanism of natural organ-isms.The definition,idea and flow of the algorithm are introduced,and relevant rules on metabolic energy and change in the surroundings where artificial-life individuals live are depicted.Furthermore,key parameters of the algorithm are systematically analyzed.Test results show that the algorithm has quasi-life traits that include being autonomous,evolutionary,and self-adaptive.These traits are highly fit for optimization problems of life-like sys-tems such as the location-allocation problem of a distri-bution network system.展开更多
基金supported by the National Social Science Foundation of China[Grant Number.19XJY007].
文摘Climate change is a global issue that poses a significant risk to the global economy and therefore warrants coordinated collective action.Employing a questionnaire survey in China,this study presents urban residents'behavioral response to climate change and its influencing factors.The results indicated that urban residents in Tianjin often took low-cost,intuitive,and quickly implementable actions,namely behavioral coping responses.Proactive adaptive behavior was also evident,which involved greater financial investment.Furthermore,according to regression analysis results of urban residents'behavior and its influencing factors,knowledge of climate change manifested a positive correlation with urban residents'behavioral coping response.In contrast,cost manifested a negative correlation with urban residents'proactive adaptive behavior,which was a more complex,costly,and challenging anticipatory action.Knowledge of climate change manifested a positive correlation with both behavioral coping response and proactive adaptive behavior.Finally,recommendations for encouraging beneficial behaviors among urban residents are suggested.
基金supported by the Fundamental Research Funds for the Central Universities(BLX202147)the Joint Fund for Regional Innovation and Development of NSFC(U22A20563).
文摘Throughout evolutionary history,animals are finely tuned to adjust their behaviors corresponding to environmental variations.Behavioral flexibility represents an important component of a species'adaptive capacity in the face of rapid anthropogenetic environmental change,and knowledge of animal behaviors is increasingly recognized in conservation biology.In aquatic ecosystem,variation of water depth is a key factor affecting the availability of food;thus,the foraging behaviors of many waterbirds,especially piscivores.In this study,we compared the foraging behaviors of the Scaly-sided Merganser(Mergus squamatus),an endangered migratory diving duck endemic to East Asia,in habitats with different water depths(Shallow waters:0–40 cm;Deep waters:40–300 cm),using video camera records obtained from the known wintering sites during three winters from 2018 to 2020.Further,the energy expenditure of foraging behavior profile and energy intake based on fish sizes were calculated to study the foraging energetics.In total,200 effective video footages that contained 1086 min with 17,995 behaviors and 163 events of catching fish were recorded.Results showed that:1)time length for fishing(including eye-submerging,head-dipping,diving and food handling)of M.squamatus in shallow waters was significantly more than in deep waters;2)M.squamatuss spent significantly more time for preparing(including vigilance,preening and swimming)in deep waters than in shallow waters;3)the mean catch rate was 0.28 fish/min in shallow waters,which is significantly higher than the value of 0.13 fish/min in deep waters;4)despite the distinct foraging behavior profiles and energy intakes,M.squamatus showed similar energetics in shallow and deep waters.We concluded that M.squamatus is a good example of behavioral flexibility that aligns with expectations of optimal foraging theory,in that it behaves in accordance to resource availability in different environments,resulting in high foraging efficiency.
文摘The emergence of adventure tourism is indicative of a process of commodification commensurate with the expansive mechanisms of the hospitality industry.The tension between excitement,thrill,and safety is on-going however and the emergence of climbing walls in urban areas has provided new ways of becoming a climber:It is in the interests of climbing as business to normalise pay-to-climb conditions.Such overt commercial connections are anathema to real climbers;nevertheless the convenience of climbing walls means they are well populated and used.The present study investigates the attitudes and methods of engagement by a group of older climbers who,for the most part,started climbing in their youth before climbing walls were commonplace.A typology of climbing types is presented as a framework for discussion.The methodology is ethnographic and the findings suggest that,despite subscribing to an organic and outdoor adventure climbing ethos in their youth,this group remains active and adventurously inclined as they consider wall-climbing to be making a positive contribution to their present collective identity.
文摘Thermal comfort is an important factor in hostel buildings when the aim is to maximize the productivity of the students.Due to the extreme weather conditions,achieving thermal comfort in a hostel building in a hot and humid climate is even more difficult.Studies conducted in naturally ventilated hostel buildings in warm-humid climates involved the influence of outdoor air temperature only up to 34.4℃ and have been conducted in a specific season.In contrast,the Tiruchirappalli climate is characterized by a higher range of environmental variables.Therefore,to understand the thermal comfort conditions and usage of the environmental controls in naturally ventilated hostel buildings at the higher range of the environmental variables,a thermal comfort field study spread over one year was carried out at the National Institute of Technology,Tiruchirappalli,India,in twenty-seven hostel buildings.This study relies on field observation and thermal comfort responses from 2028 questionnaires collected from the students between September 2019 to August 2020.The analysis revealed a neutral temperature of 29.5℃ and a comfort range from 26.1℃ to 32.8℃,indicating a wide range of ther-mal adaptation than suggested by the National Building Code of India and ASHRAE standard 55.The preferred temperature was 27.8℃,indicating that students preferred a cooler environment.Acceptability with sweating conditions extended the upper limit of thermal acceptability from 31.8℃ to 32.4℃.The use of a mosquito net can increase the probability of opening a window.Results indicated that overall behavioral adjustment could extend the comfort limits.The study results would be helpful to develop guidelines and designs for naturally ventilated hostel buildings in warm and humid climates that will contribute to reducing energy demand.
基金Projects(51378119,51578150)supported by the National Natural Science Foundation of China
文摘Advanced traveler information systems （ATIS） can not only improve drivers＇ accessibility to the more accurate route travel time information, but also can improve drivers＇ adaptability to the stochastic network capacity degradations. In this paper, a mixed stochastic user equilibrium model was proposed to describe the interactive route choice behaviors between ATIS equipped and unequipped drivers on a degradable transport network. In the proposed model the information accessibility of equipped drivers was reflected by lower degree of uncertainty in their stochastic equilibrium flow distributions, and their behavioral adaptability was captured by multiple equilibrium behaviors over the stochastic network state set. The mixed equilibrium model was formulated as a fixed point problem defined in the mixed route flows, and its solution was achieved by executing an iterative algorithm. Numerical experiments were provided to verify the properties of the mixed network equilibrium model and the efficiency of the iterative algorithm.
基金We would like to thank the following organizations for providing funds for this study:FAPESB(RED0045/2014,JCB0026/2016)CNPq(443249/2014-8,465767/2014-1)CAPES(23038.000776/2017-54).
文摘Urbanization has dramatic impacts on natural habitats and such changes may potentially drive local adaptation of urban populations.Behavioral change has been specifically shown to facilitate the fast adaptation of birds to changing environments,but few studies have investigated the genetic mechanisms of this process.Such investigations could provide insights into questions about both evolutionary theory and management of urban populations.In this study,we investigated whether local adaptation has occurred in urban populations of a Neotropical bird species,Coereba flaveola,specifically addressing whether observed behavioral adaptations are correlated to genetic signatures of natural selection.To answer this question,we sampled 24 individuals in urban and rural environments,and searched for selected loci through a genome-scan approach based on RADseq genomic data,generated and assembled using a reference genome for the species.We recovered 46 loci as putative selection outliers,and 30 of them were identified as associated with biological processes possibly related to urban adaptation,such as the regulation of energetic metabolism,regulation of genetic expression,and changes in the immunological system.Moreover,genes involved in the development of the nervous system showed signatures of selection,suggesting a link between behavioral and genetic adaptations.Our findings,in conjunction with similar results in previous studies,support the idea that cities provide a similar selective pressure on urban populations and that behavioral plasticity may be enhanced through genetic changes in urban populations.
文摘This paper investigates the effect of factors on Farmers Adaptation Behavior in Water Scarcity Conditions in Rural Communities of Sabzevar,Iran.A survey questionnaire was used for collecting data,the study population was 120 farmers in rural Sabzevar County selected based on the Cochran formula.A questionnaire was designed for the target group for the measurement of on farm adaptation behavior in water scarcity conditions.Research models were drawn using structural equation modeling and the relationships between latent variables and indicators.The findings indicate that there is a significant relationship between awareness and adaptation behavior.Meanwhile,there is a significant relationship among network and media on farmer's perception about water scarcity and their activities toward better management of water in the critical condition.There are also significant relationships among perception and awareness with intention however,intention do not effect on adaptation behavior strongly.In other words,even the that means farmers had information about crisis,they are not able to have not operational plans to confront the water scarcity conditions.
基金the Swedish Governmental Agency for Innovation Systems(Vinnovagrant no.2018-02891).
文摘Purpose–This paper aims to explore whether drivers would adapt their behavior when they drive among automated vehicles(AVs)compared to driving among manually driven vehicles(MVs).Understanding behavioral adaptation of drivers when they encounter AVs is crucial for assessing impacts of AVs in mixed-traffic situations.Here,mixed-traffic situations refer to situations where AVs share the roads with existing nonautomated vehicles such as conventional MVs.Design/methodology/approach–A driving simulator study is designed to explore whether such behavioral adaptations exist.Two different driving scenarios were explored on a three-lane highway:driving on the main highway and merging from an on-ramp.For this study,18 research participants were recruited.Findings–Behavioral adaptation can be observed in terms of car-following speed,car-following time gap,number of lane change and overall driving speed.The adaptations are dependent on the driving scenario and whether the surrounding traffic was AVs or MVs.Although significant differences in behavior were found in more than 90%of the research participants,they adapted their behavior differently,and thus,magnitude of the behavioral adaptation remains unclear.Originality/value–The observed behavioral adaptations in this paper were dependent on the driving scenario rather than the time gap between surrounding vehicles.This finding differs from previous studies,which have shown that drivers tend to adapt their behaviors with respect to the surrounding vehicles.Furthermore,the surrounding vehicles in this study are more“free flow’”compared to previous studies with a fixed formation such as platoons.Nevertheless,long-term observations are required to further support this claim.
基金This work was supported by the Dampier Bunbury Pipeline,Perth,Western AustraliaThe Peregrine Fund,Boise IDthe Department of Biodiversity,Conservation and Attractions,Western Australia.J.S.was supported by the Australian Government Research Training Program Scholarship.
文摘Rapid learning in the young of most endothermic animals can be expected to be favored by natural selection because early independence reduces the period of vulnerability.Cases of comparatively slow juvenile development continue,therefore,to attract scientific attention.In most species of birds,including raptors,the young depend on their parents for some time after fledging for the provisioning of food and for protection while they learn to become nutritionally and otherwise independent.Among raptors,post-fledging dependence periods that exceed 6 months are exclusive to the largest species and these have reproductive cycles that exceed 12 months.By contrast,young of the medium-sized grey falcon Falco hypoleucos have been reported in close company with their parents up to 12 months after fledging,that is,at a time when the adults are expected to breed again.We investigated the occurrence and characteristics of prolonged adult–juvenile association relative to other falcons and similar-sized raptors.We found that the behavioral development of grey falcon young is extremely delayed,and that they even depend nutritionally on their parents for up to 12 months after fledging.We suggest that these 2 distinctive features are,ultimately,adaptations of the grey falcon to its extreme environment,Australia’s arid and semi-arid zone,one of the hottest environments in the world.
基金support from the Research Center in Pure and Applied Mathematics and the Department of Mathematics at Universidad de Costa Rica.
文摘Throughout the progress of epidemic scenarios,individuals in different health classes are expected to have different average daily contact behavior.This contact heterogeneity has been studied in recent adaptive models and allows us to capture the inherent differences across health statuses better.Diseases with reinfection bring out more complex scenarios and offer an important application to consider contact disaggregation.Therefore,we developed a nonlinear differential equation model to explore the dynamics of relapse phenomena and contact differences across health statuses.Our incidence rate function is formulated,taking inspiration from recent adaptive algorithms.It incorporates contact behavior for individuals in each health class.We use constant contact rates at each health status for our analytical results and prove conditions for different forward-backward bifurcation scenarios.The relationship between the different contact rates heavily in-fluences these conditions.Numerical examples highlight the effect of temporarily recov-ered individuals and initial conditions on infected population persistence.
基金Major Program of the National Social Science Fund of China“Capacity Basis,Capacity Structure and Promotion Mechanism for High-Quality Development of China”(19ZDA049)National Natural Science Foundation of China“Diffusion Mechanism and Policy Effects of Local Environmental Governance Policies:A Case Study on the‘River-Director’System”(71903085)supported by the Fundamental Research Funds for the Central Universities“Economic Effects of Climate Change:Theoretical Mechanism and Evidence from China”(010414370114).
文摘In order to comprehensively study the influence of climate change on economic growth and energy conservation&emission reduction,this paper fi rst uses the non-radial directional distance function(NDDF)to calculate the city-level green economic efficiency in China during 2003-2016.The causal effect of daily temperature changes on green economic efficiency is then identifi ed to evaluate the economic consequences of climate change.It fi nds that r elative to the 6~12℃temperature benchmark,any decrease or increase in temperature will pose negative influence on green economic efficiency;moreover,such effects are only observed in developed cities,but not signifi cant in less-developed ones.This refl ects that the economic consequences of climate change are“robbing the rich”to some extents,which differs widely from the“pro-poor”conclusion in the majority of literature previously.Subject to the robustness test and with possible competitive explanations excluded,this finding still stands.The mechanism test reveals that temperature rise brings about economic consequences that“rob the rich”by affecting labor productivity,efficiency of energy conservation&emission reduction and execution of environmental regulations by local government.This study brings a different perspective for understanding the economic consequences of climate change and offers empirical basis for identifying responsibilities of local government in climate governance.
基金supported by the National Natural Science Foundation of China(Grant Nos.70431003,70571077,75103012).
文摘Based on the characteristics of colony emer-gence of artificial organisms,their dynamic interaction with the environment,and the food-chain crucial to the life system,the rules of local activities of artificial organ-isms at different levels are defined.The article proposes an artificial life-based algorithm,which is referred to as the food-chain algorithm.This algorithm optimizes computa-tion by simulating the evolution of natural ecosystems and the information processing mechanism of natural organ-isms.The definition,idea and flow of the algorithm are introduced,and relevant rules on metabolic energy and change in the surroundings where artificial-life individuals live are depicted.Furthermore,key parameters of the algorithm are systematically analyzed.Test results show that the algorithm has quasi-life traits that include being autonomous,evolutionary,and self-adaptive.These traits are highly fit for optimization problems of life-like sys-tems such as the location-allocation problem of a distri-bution network system.
