With the knowledge that cuckoos and cowbirds lay their eggs parasitically,and that some hosts eject parasitic eggs,ornithologists began to ponder the question of how host females discriminate between a foreign egg and...With the knowledge that cuckoos and cowbirds lay their eggs parasitically,and that some hosts eject parasitic eggs,ornithologists began to ponder the question of how host females discriminate between a foreign egg and their own eggs,wondering how hosts 'know' which egg to remove.Results of one of the rst uncontrolled experiments were inappropriately interpreted to imply ejection was based on discordancy,with hosts simply ejecting the egg in the minority,or the 'odd-looking' egg.Controlled experiments eventually revealed that hosts rst learn the appearance of own their eggs and discriminate between them and any odd egg in their nest,regardless of which egg type is in the minority.Recent work has shown that discordancy may play a role in discrimination by males mated successively with females that lay polymorphic eggs.We examine the details of the early experiments,in light of recent advances in studies of egg recognition.An ability to recognize eggs also has been extended,implicitly,to include obligate brood parasites,as it underlies several hypotheses in explanation of the behavior of parasites toward their hosts.Egg recognition in parasites,however,has not been experimentally con rmed,nor has a mechanism been identi ed by which parasites could discriminate between their own eggs and the other eggs in a nest.We review hypotheses(parasite competition,egg removal and multiple parasitism,ma a,farming) that require the ability of obligate brood parasites to discriminate eggs at di erent levels and the potential mechanisms used by parasites to recognize their own eggs and suggest experiments to test for egg discrimination.An assessment of the egg recognition ability of parasites is germane to our understanding of how parasites counteract defenses of hosts.展开更多
Mutualisms are cooperative interactions between members of different species. We focus on obligate mutualism, where each species cannot survive without the other. From a theoretical aspect, obligate mutualism is simil...Mutualisms are cooperative interactions between members of different species. We focus on obligate mutualism, where each species cannot survive without the other. From a theoretical aspect, obligate mutualism is similar to the relationship between male and female. Empirical data indicate a sex-ratio selection: male and female have a specific ratio in their population sizes. In the present paper, we apply lattice model to obligate mutualism between two species, and present a theory of “ratio selection” which is a generalization of sex-ratio selection. Computer simulations are carried out by two methods: local and global interactions. In the former, interactions occur between neighbouring cells, while in the latter they occur between any pair of cells. Simulations in both interactions show the so-called Allee effect: both species can survive, when both densities are large in some extent. However, we find a large difference between local and global simulations. In the case of local interaction, restriction for survival is found to be extremely severe compared to global interaction. Both species require a proper ratio for their sustainability. This result leads to the theory of ratio selection: when interaction occurs locally, the ratio of both species is uniquely determined. We discuss that the ratio selection explains not only the evolution of endosymbionts from free-living ancestors but also the evolution from endosymbionts to organelles.展开更多
By constructing a suitable Lyapunov function,sufficient conditions which ensure the global asymptotical stability of the positive equilibrium and boundary equilibrium of an obligate Lotka-Volterra mutualism model are ...By constructing a suitable Lyapunov function,sufficient conditions which ensure the global asymptotical stability of the positive equilibrium and boundary equilibrium of an obligate Lotka-Volterra mutualism model are obtained,respectively.It is shown that the conditions which ensure the local stability of the nonnegative equilibria is enough to ensure their global asymptotical stability.Our result supplements and complements some known result.展开更多
Long long ago,there was a young girl named Hua Mulan.Her father was a soldier.One day,the emperor needed more soldiers.Each family had to send one man.But Mulan’s father was too old,and her brother was too young.So,M...Long long ago,there was a young girl named Hua Mulan.Her father was a soldier.One day,the emperor needed more soldiers.Each family had to send one man.But Mulan’s father was too old,and her brother was too young.So,Mulan cut her long hair short,dressed up as a man,and joined the army in place of her father.展开更多
The legal protection of human dignity can be explored from the perspective of regulating“hate speech.”The practices of most countries worldwide demonstrate that human dignity serves as a fundamental value limiting t...The legal protection of human dignity can be explored from the perspective of regulating“hate speech.”The practices of most countries worldwide demonstrate that human dignity serves as a fundamental value limiting the freedom of expression.Legally protected human dignity encompasses three levels of meaning:the dignity of life as an inherent aspect of human existence,the dignity of individuals as members of specific groups,and the personal dignity of individuals as unique beings.These three levels collectively emphasize the principle that human beings are ends in themselves,underscoring that individuals must not be degraded to mere means or subjected to harm.The inherent nature of human dignity necessitates its protection by both the state and societal entities.Traditionally,the safeguarding of human dignity has primarily depended on state intervention.However,with the advent of the digital age,this responsibility has increasingly extended to social entities,imposing changes of enhanced and expanded obligations of respect.Consequently,the key to protecting human dignity lies in adjusting the allocation of responsibilities between the state and society in accordance with the development of the times.Under the guidance of human dignity as a constitutional value,China should focus on establishing a comprehensive protection system by improving legislation,law enforcement,and judicial practices.This includes specifying the obligations of social entities and constructing multi-level regulatory mechanisms to form an effective system of protection by the state and society.展开更多
The understanding of the scope of protection for the right to health should not be limited to fragmented descriptions in departmental laws,such as those focusing on rights,interests,or legal benefits.Instead,it should...The understanding of the scope of protection for the right to health should not be limited to fragmented descriptions in departmental laws,such as those focusing on rights,interests,or legal benefits.Instead,it should be analyzed holistically within the constitutional framework of fundamental rights.From the perspective of defense right function,the right to health addresses physiological harm that progresses through stages of“risk-danger-infringement,”psychological harm that targets inner distress,and minor harm arising from challenges in social adaptation,to clarify the negative defensive obligations of the state to prevent health-related harm.From the perspectives of the beneficiary right function and the objective value order function,the right to health requires a minimum level of constitutional protection and delineating the positive obligations of the state to ensure it through the fulfillment of basic obligations in healthcare and health promotion.展开更多
The incorporation of human rights clauses into the constitution has propelled the innovation of fundamental rights hermeneutics in terms of the subjects of the legal relationships of fundamental rights,the nature of f...The incorporation of human rights clauses into the constitution has propelled the innovation of fundamental rights hermeneutics in terms of the subjects of the legal relationships of fundamental rights,the nature of fundamental rights,the forms of state obligations,the scope of fundamental rights,among other aspects.Regarding the subjects of the legal relationships of fundamental rights,human rights clauses have expanded the subjects of fundamental rights from citizens to natural persons.They have also narrowed down the duty-bearing subjects directed by fundamental rights in clauses that do not define duty-bearing subjects from all entities to state public power.Additionally,in fundamental rights clauses that stipulate private entities as duty-bearing subjects,the duty-bearing subjects have been narrowed down from all private entities to social public power entities.In terms of the nature of fundamental rights,human rights clauses have endowed each specific basic right with dual characteristics of the right to respect and the right to protection.Regarding the forms of state obligations,human rights clauses have established the state obligations corresponding to each specific basic right as obligations to respect and to protect.In terms of the scope of fundamental rights,human rights clauses do not have the function of independently justifying unenumerated fundamental rights,but they can assist other clauses in justifying unenumerated fundamental rights,thereby expanding the scope of fundamental rights to a limited extent.展开更多
Traditional constitutional theory holds that Article 33,Paragraph 4 of the Chinese Constitution establishes the principle of the consistency of rights and obligations.However,with the evolution of constitutional theor...Traditional constitutional theory holds that Article 33,Paragraph 4 of the Chinese Constitution establishes the principle of the consistency of rights and obligations.However,with the evolution of constitutional theory and practice,its interpretation has shifted.It is increasingly viewed as a concretization of the principle of equality,although this perspective has not been thoroughly substantiated in academic circles.Upon closer analysis,interpreting this provision as the“consistency of rights and obligations”reveals several issues,including counterevidence from the constitutional drafting history,a lack of internal coherence,and a misalignment with the functions of the Constitution.By revisiting the specific context of this provision,it can be understood as an anti-privilege clause,serving as a special annotation of the equality principle.This approach enables a harmonious interpretation of this provision alongside other constitutional provisions.展开更多
Viral diseases have been studied in-depth for reducing quality,yield,health and longevity of the fruit,to highlight the economic losses.Positive-sense single-stranded RNA viruses are more devastating among all viruses...Viral diseases have been studied in-depth for reducing quality,yield,health and longevity of the fruit,to highlight the economic losses.Positive-sense single-stranded RNA viruses are more devastating among all viruses that infect fruit trees.One of the best examples is papaya ringspot virus(PRSV).It belongs to the genus Potyvirus and it is limited to cause diseases on the family Chenopodiaceae,Cucurbitaceae and Caricaceae.This virus has a serious threat to the production of papaya,which is famous for its high nutritional and pharmaceutical values.The plant parts such as leaves,latex,seeds,fruits,bark,peel and roots may contain the biological compound that can be isolated and used in pharmaceutical industries as a disease control.Viral disease symptoms consist of vein clearing and yellowing of young leaves.Distinctive ring spot patterns with concentric rings and spots on fruit reduce its quality and taste.The virus has two major strains P and W.The former cause disease in papaya and cucurbits while the later one in papaya.Virion comprises 94.4%protein,including a 36 kDa coat protein which is a component responsible for a non-persistent transmission through aphids,and 5.5%nucleic acid.Cross protection,development of transgenic crops,exploring the resistant sources and induction of pathogen derived resistance have been recorded as effective management of PRSV.Along with these practices reduced aphid population through insecticides and plant extracts have been found ecofriendly approaches to minimize the disease incidence.Adoption of transgenic crops is a big challenge for the success of disease resistant papaya crops.The aim of this review is to understand the genomic nature of PRSV,detection methods and the different advanced control methods.This review article will be helpful in developing the best management strategies for controlling PRSV.展开更多
Glochidion(Phyllanthaceae;leafflower trees)is a genus of trees which is widely reported to be pollinated by leafflower moths(Gracillariidae:Epicephala)in temperate and subtropical Asia,Australia,and the Pacific island...Glochidion(Phyllanthaceae;leafflower trees)is a genus of trees which is widely reported to be pollinated by leafflower moths(Gracillariidae:Epicephala)in temperate and subtropical Asia,Australia,and the Pacific islands.However,the pollination ecology of Glochidion is not well described from tropical Asia,the region where it is most species-rich at both local(<9 spp.)and regional(~200 spp.)scales.Here we report investigations of pollination biology and species-specificity of five Glochidion species in tropical Southeast Asia(Cambodia).Through nocturnal observations and fruit dissections,we find that at least three and likely five Glochidion species in Cambodia are pollinated by seed-parasitic leafflower moths.We find no evidence that any of these leafflower moths are non-mutualistic parasites,despite known examples of such parasites of this mutualism elsewhere in Asia.While the presence of a single larva in a fruit results in only a fraction of seeds being consumed,the presence of more than one larva per fruit-a frequent occurrence in some species—can result in almost all seeds within the fruit being infested.Multilocus phylogenetic analysis indicates that there are five different minimally monophyletic leafflower moth clades,each of which pollinates a unique Glochidion host species.Our results indicate that in its center of diversity in tropical Asia this system is an obligate pollination mutualism as previously described at the global margins of its distribution.These findings provide insights into the processes that generate and maintain biodiversity and maintain mutualism stability in plant-insect interactions in this biodiversity hotspot.展开更多
Background:In fire-prone ecosystems,plant species having different post-fire regeneration strategies(PFRS)coexist at the local scale while showing different growth dynamics.To evaluate the effect of PFRS on species re...Background:In fire-prone ecosystems,plant species having different post-fire regeneration strategies(PFRS)coexist at the local scale while showing different growth dynamics.To evaluate the effect of PFRS on species regeneration,we investigated the plant communities burned in different years in the central Yunnan Province,Southwest China.Several indicators describing plant growth and population importance were measured to compare the regeneration of four dominant tree species,including one facultative seeders(FS)and three obligate resprouters(OR).Partial correlation and mixed linear effect modeling were applied to disentangle the contribution of intrinsic and environmental factors to the interspecific variation in post-fire regeneration.Results:We identified two subtypes of plant growth strategy in the early post-fire stage for OR species;i.e.,number growth(ORþN)priority and height growth(ORþH)priority for sprouting stems.Generally,the FS and OR species varied in height growth rate with different temporal dynamics.The ORþN species occupied post-fire space horizontally with more resprouts and larger coverage than ORþH and FS species at the earlier stage.In contrast,the ORþH species generally had far less resprouts per clump,more variations in stem height and basal diameter.Factor analysis showed that the variation of post-fire plant regeneration was not effectively explained by environmental factors(R2<20%);however,the linear mixed models with the modified PFRS as a random effect substantially increased the explanation.Conclusions:The differentiated regeneration dynamics and growth priorities in the four dominant tree species indicated a critical dichotomy of habitat occupation strategy for the resprouter species during the early stage of post-fire forest restoration.Our study uncovered a trade-off between height versus number growth priority in the post-fire tree growth strategy and provides a novel perspective in understanding the living space occupying(niche partitioning)process and species coexistence in post-fire forest community assembly.展开更多
The International Health Regulations was enforced in June 2007,emphasizing the obligation of State Parties to detect,report,and respond to public health emergencies[1].An effective public health response requires a co...The International Health Regulations was enforced in June 2007,emphasizing the obligation of State Parties to detect,report,and respond to public health emergencies[1].An effective public health response requires a coordinated laboratory response in the Ministry of Health(MOH)network with credible laboratories capable of providing accurate and reliable results in a timely manner to enable effective public health measures展开更多
一、教学设计思路1.教学目标（Teaching objectives）（1）To teach new words：slide show,object,wave,shelter.（2）To enable students to use modal verb＂may＂to talk about possibility and＂should＂to talk about obligation....一、教学设计思路1.教学目标（Teaching objectives）（1）To teach new words：slide show,object,wave,shelter.（2）To enable students to use modal verb＂may＂to talk about possibility and＂should＂to talk about obligation.（3）To make students know the dangerous results of typhoons and learn to take precautions.展开更多
In the early Middle Ages the Europe was a chaotic social environment.The empire was so vast that no king could build a centralized government,so the king depended on counts to administrate the regions.There were confl...In the early Middle Ages the Europe was a chaotic social environment.The empire was so vast that no king could build a centralized government,so the king depended on counts to administrate the regions.There were conflicts,wars,invasion and famine at that time.The decentralized government could not protect people from these sufferings,so the people just could search for the strong to secure them.The lord could provide protection to his vassals and grant fiefs to his vassals,and in turn vassals needed to perform their obligation to the lord.These obligation included loyalty,military service,assistance,offering material and counsel which stabilized the area that the lord ruled.The feudalism in the administration of Merovingian and Carolingian even after the breakup of Carolingian could illustrate the stable units of the empire.展开更多
The sea level has increased abruptly in the Indian Ocean in the last four decades.Data shows that the increase in sea level is not homogeneous.The rise in bay of Bengal is more than that of the Arabian Sea. Global war...The sea level has increased abruptly in the Indian Ocean in the last four decades.Data shows that the increase in sea level is not homogeneous.The rise in bay of Bengal is more than that of the Arabian Sea. Global warming has caused an increase in sea surface temperature.The sea surface temperature has a direct impact on the sea level rise as well as on the intensity and frequency of storms and cyclones.This展开更多
Although there is no uniform concept about social forestry in the world,its aim of servicing mankind is commonly considered,and the importance ofwomen’s participation is recognized. Women in China,as an important par...Although there is no uniform concept about social forestry in the world,its aim of servicing mankind is commonly considered,and the importance ofwomen’s participation is recognized. Women in China,as an important part of the labor force involved in thedevelopment of social forestry,can be divided into three categories according tothe type of women’s participation. Firstly women(as well as men)have the obligation to participate in展开更多
基金funded chiefly by grants from the Natural Sciences and Engineering Research Council of Canada
文摘With the knowledge that cuckoos and cowbirds lay their eggs parasitically,and that some hosts eject parasitic eggs,ornithologists began to ponder the question of how host females discriminate between a foreign egg and their own eggs,wondering how hosts 'know' which egg to remove.Results of one of the rst uncontrolled experiments were inappropriately interpreted to imply ejection was based on discordancy,with hosts simply ejecting the egg in the minority,or the 'odd-looking' egg.Controlled experiments eventually revealed that hosts rst learn the appearance of own their eggs and discriminate between them and any odd egg in their nest,regardless of which egg type is in the minority.Recent work has shown that discordancy may play a role in discrimination by males mated successively with females that lay polymorphic eggs.We examine the details of the early experiments,in light of recent advances in studies of egg recognition.An ability to recognize eggs also has been extended,implicitly,to include obligate brood parasites,as it underlies several hypotheses in explanation of the behavior of parasites toward their hosts.Egg recognition in parasites,however,has not been experimentally con rmed,nor has a mechanism been identi ed by which parasites could discriminate between their own eggs and the other eggs in a nest.We review hypotheses(parasite competition,egg removal and multiple parasitism,ma a,farming) that require the ability of obligate brood parasites to discriminate eggs at di erent levels and the potential mechanisms used by parasites to recognize their own eggs and suggest experiments to test for egg discrimination.An assessment of the egg recognition ability of parasites is germane to our understanding of how parasites counteract defenses of hosts.
文摘Mutualisms are cooperative interactions between members of different species. We focus on obligate mutualism, where each species cannot survive without the other. From a theoretical aspect, obligate mutualism is similar to the relationship between male and female. Empirical data indicate a sex-ratio selection: male and female have a specific ratio in their population sizes. In the present paper, we apply lattice model to obligate mutualism between two species, and present a theory of “ratio selection” which is a generalization of sex-ratio selection. Computer simulations are carried out by two methods: local and global interactions. In the former, interactions occur between neighbouring cells, while in the latter they occur between any pair of cells. Simulations in both interactions show the so-called Allee effect: both species can survive, when both densities are large in some extent. However, we find a large difference between local and global simulations. In the case of local interaction, restriction for survival is found to be extremely severe compared to global interaction. Both species require a proper ratio for their sustainability. This result leads to the theory of ratio selection: when interaction occurs locally, the ratio of both species is uniquely determined. We discuss that the ratio selection explains not only the evolution of endosymbionts from free-living ancestors but also the evolution from endosymbionts to organelles.
基金supported by the Natural Science Foundation of Pujian Province(2013J01011,2013J01010)the Foundation of Fujian Edication Bureau(JA13361)
文摘By constructing a suitable Lyapunov function,sufficient conditions which ensure the global asymptotical stability of the positive equilibrium and boundary equilibrium of an obligate Lotka-Volterra mutualism model are obtained,respectively.It is shown that the conditions which ensure the local stability of the nonnegative equilibria is enough to ensure their global asymptotical stability.Our result supplements and complements some known result.
文摘Long long ago,there was a young girl named Hua Mulan.Her father was a soldier.One day,the emperor needed more soldiers.Each family had to send one man.But Mulan’s father was too old,and her brother was too young.So,Mulan cut her long hair short,dressed up as a man,and joined the army in place of her father.
文摘The legal protection of human dignity can be explored from the perspective of regulating“hate speech.”The practices of most countries worldwide demonstrate that human dignity serves as a fundamental value limiting the freedom of expression.Legally protected human dignity encompasses three levels of meaning:the dignity of life as an inherent aspect of human existence,the dignity of individuals as members of specific groups,and the personal dignity of individuals as unique beings.These three levels collectively emphasize the principle that human beings are ends in themselves,underscoring that individuals must not be degraded to mere means or subjected to harm.The inherent nature of human dignity necessitates its protection by both the state and societal entities.Traditionally,the safeguarding of human dignity has primarily depended on state intervention.However,with the advent of the digital age,this responsibility has increasingly extended to social entities,imposing changes of enhanced and expanded obligations of respect.Consequently,the key to protecting human dignity lies in adjusting the allocation of responsibilities between the state and society in accordance with the development of the times.Under the guidance of human dignity as a constitutional value,China should focus on establishing a comprehensive protection system by improving legislation,law enforcement,and judicial practices.This includes specifying the obligations of social entities and constructing multi-level regulatory mechanisms to form an effective system of protection by the state and society.
文摘The understanding of the scope of protection for the right to health should not be limited to fragmented descriptions in departmental laws,such as those focusing on rights,interests,or legal benefits.Instead,it should be analyzed holistically within the constitutional framework of fundamental rights.From the perspective of defense right function,the right to health addresses physiological harm that progresses through stages of“risk-danger-infringement,”psychological harm that targets inner distress,and minor harm arising from challenges in social adaptation,to clarify the negative defensive obligations of the state to prevent health-related harm.From the perspectives of the beneficiary right function and the objective value order function,the right to health requires a minimum level of constitutional protection and delineating the positive obligations of the state to ensure it through the fulfillment of basic obligations in healthcare and health promotion.
基金the Ministry of Education’s Major Special Project for Philosophical and Social Science Research,“A Study on the Conceptual System of China’s Independent Legal Knowledge System”(Project Number 2023JZDZ014)the Ministry of Education’s Humanities and Social Science Research Planning Fund Project,“A Study on the Improvement of the Villager Self-Governance System in the Context of Land Circulation”(Project Number 19YJA820027).
文摘The incorporation of human rights clauses into the constitution has propelled the innovation of fundamental rights hermeneutics in terms of the subjects of the legal relationships of fundamental rights,the nature of fundamental rights,the forms of state obligations,the scope of fundamental rights,among other aspects.Regarding the subjects of the legal relationships of fundamental rights,human rights clauses have expanded the subjects of fundamental rights from citizens to natural persons.They have also narrowed down the duty-bearing subjects directed by fundamental rights in clauses that do not define duty-bearing subjects from all entities to state public power.Additionally,in fundamental rights clauses that stipulate private entities as duty-bearing subjects,the duty-bearing subjects have been narrowed down from all private entities to social public power entities.In terms of the nature of fundamental rights,human rights clauses have endowed each specific basic right with dual characteristics of the right to respect and the right to protection.Regarding the forms of state obligations,human rights clauses have established the state obligations corresponding to each specific basic right as obligations to respect and to protect.In terms of the scope of fundamental rights,human rights clauses do not have the function of independently justifying unenumerated fundamental rights,but they can assist other clauses in justifying unenumerated fundamental rights,thereby expanding the scope of fundamental rights to a limited extent.
基金This paper is an phased result of the“Research on Constitutional Review Methods of fundamental rights Restrictions”(Project Number 21BFX040),a general project of 2021 supported by National Social Science Fund of China.
文摘Traditional constitutional theory holds that Article 33,Paragraph 4 of the Chinese Constitution establishes the principle of the consistency of rights and obligations.However,with the evolution of constitutional theory and practice,its interpretation has shifted.It is increasingly viewed as a concretization of the principle of equality,although this perspective has not been thoroughly substantiated in academic circles.Upon closer analysis,interpreting this provision as the“consistency of rights and obligations”reveals several issues,including counterevidence from the constitutional drafting history,a lack of internal coherence,and a misalignment with the functions of the Constitution.By revisiting the specific context of this provision,it can be understood as an anti-privilege clause,serving as a special annotation of the equality principle.This approach enables a harmonious interpretation of this provision alongside other constitutional provisions.
文摘Viral diseases have been studied in-depth for reducing quality,yield,health and longevity of the fruit,to highlight the economic losses.Positive-sense single-stranded RNA viruses are more devastating among all viruses that infect fruit trees.One of the best examples is papaya ringspot virus(PRSV).It belongs to the genus Potyvirus and it is limited to cause diseases on the family Chenopodiaceae,Cucurbitaceae and Caricaceae.This virus has a serious threat to the production of papaya,which is famous for its high nutritional and pharmaceutical values.The plant parts such as leaves,latex,seeds,fruits,bark,peel and roots may contain the biological compound that can be isolated and used in pharmaceutical industries as a disease control.Viral disease symptoms consist of vein clearing and yellowing of young leaves.Distinctive ring spot patterns with concentric rings and spots on fruit reduce its quality and taste.The virus has two major strains P and W.The former cause disease in papaya and cucurbits while the later one in papaya.Virion comprises 94.4%protein,including a 36 kDa coat protein which is a component responsible for a non-persistent transmission through aphids,and 5.5%nucleic acid.Cross protection,development of transgenic crops,exploring the resistant sources and induction of pathogen derived resistance have been recorded as effective management of PRSV.Along with these practices reduced aphid population through insecticides and plant extracts have been found ecofriendly approaches to minimize the disease incidence.Adoption of transgenic crops is a big challenge for the success of disease resistant papaya crops.The aim of this review is to understand the genomic nature of PRSV,detection methods and the different advanced control methods.This review article will be helpful in developing the best management strategies for controlling PRSV.
基金the National Natural Science Foundation of China(grants no.31170217 and 31370268 to S.-X.Luo)the Chinese Academy of Sciences’"The Belt and Road"Master Fellowship Programme for providing P.Chheang a fully funded master’s scholarship。
文摘Glochidion(Phyllanthaceae;leafflower trees)is a genus of trees which is widely reported to be pollinated by leafflower moths(Gracillariidae:Epicephala)in temperate and subtropical Asia,Australia,and the Pacific islands.However,the pollination ecology of Glochidion is not well described from tropical Asia,the region where it is most species-rich at both local(<9 spp.)and regional(~200 spp.)scales.Here we report investigations of pollination biology and species-specificity of five Glochidion species in tropical Southeast Asia(Cambodia).Through nocturnal observations and fruit dissections,we find that at least three and likely five Glochidion species in Cambodia are pollinated by seed-parasitic leafflower moths.We find no evidence that any of these leafflower moths are non-mutualistic parasites,despite known examples of such parasites of this mutualism elsewhere in Asia.While the presence of a single larva in a fruit results in only a fraction of seeds being consumed,the presence of more than one larva per fruit-a frequent occurrence in some species—can result in almost all seeds within the fruit being infested.Multilocus phylogenetic analysis indicates that there are five different minimally monophyletic leafflower moth clades,each of which pollinates a unique Glochidion host species.Our results indicate that in its center of diversity in tropical Asia this system is an obligate pollination mutualism as previously described at the global margins of its distribution.These findings provide insights into the processes that generate and maintain biodiversity and maintain mutualism stability in plant-insect interactions in this biodiversity hotspot.
基金supported by the National Natural Science Foundation of China(41971228)the National Key R and D Program of the Ministry of Science and Technology of China(2017YFC0505200).
文摘Background:In fire-prone ecosystems,plant species having different post-fire regeneration strategies(PFRS)coexist at the local scale while showing different growth dynamics.To evaluate the effect of PFRS on species regeneration,we investigated the plant communities burned in different years in the central Yunnan Province,Southwest China.Several indicators describing plant growth and population importance were measured to compare the regeneration of four dominant tree species,including one facultative seeders(FS)and three obligate resprouters(OR).Partial correlation and mixed linear effect modeling were applied to disentangle the contribution of intrinsic and environmental factors to the interspecific variation in post-fire regeneration.Results:We identified two subtypes of plant growth strategy in the early post-fire stage for OR species;i.e.,number growth(ORþN)priority and height growth(ORþH)priority for sprouting stems.Generally,the FS and OR species varied in height growth rate with different temporal dynamics.The ORþN species occupied post-fire space horizontally with more resprouts and larger coverage than ORþH and FS species at the earlier stage.In contrast,the ORþH species generally had far less resprouts per clump,more variations in stem height and basal diameter.Factor analysis showed that the variation of post-fire plant regeneration was not effectively explained by environmental factors(R2<20%);however,the linear mixed models with the modified PFRS as a random effect substantially increased the explanation.Conclusions:The differentiated regeneration dynamics and growth priorities in the four dominant tree species indicated a critical dichotomy of habitat occupation strategy for the resprouter species during the early stage of post-fire forest restoration.Our study uncovered a trade-off between height versus number growth priority in the post-fire tree growth strategy and provides a novel perspective in understanding the living space occupying(niche partitioning)process and species coexistence in post-fire forest community assembly.
基金funded by the operational budget of the Disease Control Division,Ministry of Health,Malaysia
文摘The International Health Regulations was enforced in June 2007,emphasizing the obligation of State Parties to detect,report,and respond to public health emergencies[1].An effective public health response requires a coordinated laboratory response in the Ministry of Health(MOH)network with credible laboratories capable of providing accurate and reliable results in a timely manner to enable effective public health measures
文摘一、教学设计思路1.教学目标（Teaching objectives）（1）To teach new words：slide show,object,wave,shelter.（2）To enable students to use modal verb＂may＂to talk about possibility and＂should＂to talk about obligation.（3）To make students know the dangerous results of typhoons and learn to take precautions.
文摘In the early Middle Ages the Europe was a chaotic social environment.The empire was so vast that no king could build a centralized government,so the king depended on counts to administrate the regions.There were conflicts,wars,invasion and famine at that time.The decentralized government could not protect people from these sufferings,so the people just could search for the strong to secure them.The lord could provide protection to his vassals and grant fiefs to his vassals,and in turn vassals needed to perform their obligation to the lord.These obligation included loyalty,military service,assistance,offering material and counsel which stabilized the area that the lord ruled.The feudalism in the administration of Merovingian and Carolingian even after the breakup of Carolingian could illustrate the stable units of the empire.
文摘The sea level has increased abruptly in the Indian Ocean in the last four decades.Data shows that the increase in sea level is not homogeneous.The rise in bay of Bengal is more than that of the Arabian Sea. Global warming has caused an increase in sea surface temperature.The sea surface temperature has a direct impact on the sea level rise as well as on the intensity and frequency of storms and cyclones.This
文摘Although there is no uniform concept about social forestry in the world,its aim of servicing mankind is commonly considered,and the importance ofwomen’s participation is recognized. Women in China,as an important part of the labor force involved in thedevelopment of social forestry,can be divided into three categories according tothe type of women’s participation. Firstly women(as well as men)have the obligation to participate in
