Immigration relocation of the poor in rural areas is an effective targeted measure to help people out of poverty in the new normal. The structural constraints lie in the heavy pressure of land resources and environmen...Immigration relocation of the poor in rural areas is an effective targeted measure to help people out of poverty in the new normal. The structural constraints lie in the heavy pressure of land resources and environmental carrying capacity, high cost of immigration settlement and delayed counterpart funds, insufficient industrial support and difficulty in living-making. To realize the goal of targeted poverty alleviation, it demands determination and capability from the policy designer, as well the social basis. The effect imposed by the structural constraints to implementation of such policy should be paid adequate attention by public sectors. It is supposed to change the guiding direction of the policy timely and to relieve financial burden of immigration settlement and resource environmental bearing capacity through mechanism of joint efforts from internal and more external support.展开更多
In 1994, the total Chinese population in the United States were 2,017,799 which were 0.8 percent of the total US population. The Chinese population were highly concentrated by regions and among the total population. B...In 1994, the total Chinese population in the United States were 2,017,799 which were 0.8 percent of the total US population. The Chinese population were highly concentrated by regions and among the total population. By states, 42 percent of total Chinese population were found in California, 17 percent in New York. More than 80 percent total Chinese population were concentrated in 9 states. By metropolitan areas, 14.73 percent of total Chinese population were found in Los Angeles and New York respectively. Compared with the total US population, 60 percent Chinese population were found in less than 20 percent total US population and 80 percent in 50 percent. By studying the Chinese population distribution and the reason behind it, we hope to find some interesting relationships among the characteristics of this distribution and the historical, cultural, social and economic factors influencing it.展开更多
Let(Z_(n))be a branching process with immigration in a random environmentξ,whereξis an independent and identically distributed sequence of random variables.We show asymptotic properties for all the moments of Z_(n) ...Let(Z_(n))be a branching process with immigration in a random environmentξ,whereξis an independent and identically distributed sequence of random variables.We show asymptotic properties for all the moments of Z_(n) and describe the decay rates of the n-step transition probabilities.As applications,a large deviation principle for the sequence log Z_(n) is established,and related large deviations are also studied.展开更多
We are interested in the convergence rates of the submartingale Wn=Z_(n)/Π_(n)to its limit W,where(Π_(n))is the usually used norming sequence and(Z_(n))is a supercritical branching process with immigration(Y_(n))in ...We are interested in the convergence rates of the submartingale Wn=Z_(n)/Π_(n)to its limit W,where(Π_(n))is the usually used norming sequence and(Z_(n))is a supercritical branching process with immigration(Y_(n))in a stationary and ergodic environmentξ.Under suitable conditions,we establish the following central limit theorems and results about the rates of convergence in probability or in law:(i)W-W_(n) with suitable normalization converges to the normal law N(0,1),and similar results also hold for W_(n+k)-W_(n) for each fixed k∈N^(*);(ii)for a branching process with immigration in a finite state random environment,if W_(1) has a finite exponential moment,then so does W,and the decay rate of P(|W-W_(n)|>ε)is supergeometric;(iii)there are normalizing constants an(ξ)(that we calculate explicitly)such that a_(n)(ξ)(W-W_(n))converges in law to a mixture of the Gaussian law.展开更多
A kind of stochastic susceptible-exposed but not infectiousinfectious-removed (SEIR) model with constant immigration in incubation period is presented, based on a deterministic SEIR model, via the technique of paramet...A kind of stochastic susceptible-exposed but not infectiousinfectious-removed (SEIR) model with constant immigration in incubation period is presented, based on a deterministic SEIR model, via the technique of parameter perturbation which is standard in stochastic population modeling. The influence of the environmental noise as a standard Gaussian white noise on the epidemics' transmission is studied. Furthermore,the condition for the epidemics' persistence is obtained by formulating the corresponding function and using It 's formula. And the asymptotic behavior of the model near the endemic disease equilibrium is also studied. In this way, the decision support is provided in the application of this kind of stochastic SEIR model on the epidemics' prevention and control.展开更多
In order to find out the effect of human (sexual) behavior change and immigration in spreading the HIV/AIDS, a deterministic model of HIV/AIDS with infective immigration is formulated. First, basic properties of the m...In order to find out the effect of human (sexual) behavior change and immigration in spreading the HIV/AIDS, a deterministic model of HIV/AIDS with infective immigration is formulated. First, basic properties of the model, including non-negativity and boundedness of the solutions, existence of the endemic equilibrium and the basic reproduction number, R0 are analyzed. The geometrical approach is used to obtain the global asymptotic stability of endemic equilibrium. Then the basic model is extended to include several control efforts aimed at reducing infection and changing behavior. Pontryagin’s maximum principle is used to derive the optimality system and solve the system numerically. Our numerical findings are illustrated through simulations using MATLAB, which shows reliability of our model from the practical point of view.展开更多
Immigration issue is one of the major problems in China today.The implementation of disasterinduced immigration policy is a significant contributor to effectively promote targeted measures of helping people in contigu...Immigration issue is one of the major problems in China today.The implementation of disasterinduced immigration policy is a significant contributor to effectively promote targeted measures of helping people in contiguous poor areas with particular difficulties to be out of poverty.Empirical investigation has been conducted to get a systematic grasp of the implementation deviation of massive disaster-induced immigration phenomenon in southern Shaanxi area.According to the survey,phenomenon of "immigrate the rich,while abandoning the poor,more houses with fewer immigrants,four moves and four drops,poor spot choosing and relaxed project management" demands improvement of execution ability.The implementation of such public policy has a large space to improve.Enough attention should be paid to the negative impact of such deviation,and only in this way can we live up to the desired objectives.展开更多
The new immigration policies introduced by Trump administration have saturated the world's screens,which have gained a mixed reception from the higher education circles amid considerable controversy,exacerbating t...The new immigration policies introduced by Trump administration have saturated the world's screens,which have gained a mixed reception from the higher education circles amid considerable controversy,exacerbating the plight of the brain drains,hurting the enthusiasm of those who have a strong desire to live in the USA,particularly the college leavers,and triggering a decline in the quality of education for foreign students,which could be a game-changer in the competition pattern of higher education and loom large.On this occasion,in matters of China,some more robust methodologies are to jump at the chance,attract qualified personnel and present some more aggressive human resources strategies.展开更多
Immigration density magnitude and entry sizes of shrimp postlarvae to Terminos Lagoon were analyzed through sixteen fortnightly sampling from March to November in 2013, in three levels in the deepest channel of the Pu...Immigration density magnitude and entry sizes of shrimp postlarvae to Terminos Lagoon were analyzed through sixteen fortnightly sampling from March to November in 2013, in three levels in the deepest channel of the Puerto Real inlet. Trapezium nets were used with 1.5 m length, 50 cm mouth diameter and 505 μm mesh, during each sampling 12 casts of 15 minutes/each were made. It was determined the presence of two species Litopenaeus setiferus and Farfantepenaeus duorarum, with total densities of 41.284 and 37.558 Pls 100 m-3 respectively. The annual cycle of immigration of postlarvae was very similar for both species, with a clear pattern of immigration throughout the year, linked to climatic variation, with the highest densities (88%) during rainy season. There were two periods of maximum density, related to the periods of greatest reproduction of these species. The density variation among cast reflects the presence of at least two and probably more postlarvae banks, located some closer than others to the mouth of the lagoon and with different densities in them. The average sizes of the two species were 7.9 mm total length of L. setiferus and 9.0 mm of F. duorarum. The differences in income sizes of both species seem to indicate the habitat preference of adult populations, L. setiferus occurring in more coastal areas than F. duorarum. Considering the variation in density and sizes throughout each sampling period, it is evident that the larvae on the banks belong to different cohorts and that have coincided in their location in front of the mouth.展开更多
Various features of the atmospheric environment affect the number of migratory insects, besides their initial population. However, little is known about the impact of atmospheric low-frequency oscillation(10 to 90 day...Various features of the atmospheric environment affect the number of migratory insects, besides their initial population. However, little is known about the impact of atmospheric low-frequency oscillation(10 to 90 days) on insect migration. A case study was conducted to ascertain the influence of low-frequency atmospheric oscillation on the immigration of brown planthopper, Nilaparvata lugens(Stl), in Hunan and Jiangxi provinces. The results showed the following:(1) The number of immigrating N. lugens from April to June of 2007 through 2016 mainly exhibited a periodic oscillation of 10 to 20 days.(2) The 10-20 d low-frequency number of immigrating N. lugens was significantly correlated with a low-frequency wind field and a geopotential height field at 850 h Pa.(3) During the peak phase of immigration, southwest or south winds served as a driving force and carried N. lugens populations northward, and when in the back of the trough and the front of the ridge, the downward airflow created a favorable condition for N. lugens to land in the study area. In conclusion, the northward migration of N. lugens was influenced by a low-frequency atmospheric circulation based on the analysis of dynamics. This study was the first research connecting atmospheric low-frequency oscillation to insect migration.展开更多
US Latinos experience higher rates of obesity than their non-Latino counterparts. Factors associated with immigration, including length of residence in the United States, are associated with an increased risk of obesi...US Latinos experience higher rates of obesity than their non-Latino counterparts. Factors associated with immigration, including length of residence in the United States, are associated with an increased risk of obesity. Latino community health workers (CHWs) work closely with communities, and are in an ideal position to provide insight on the underlying mechanisms of the Latino obesity epidemic. Focus groups were conducted with 15 CHWs and thematic analyses were performed to explore elements associated with obesity among Latino immigrants. Emergent themes included: reduction in physical activity due to less walkable spaces, more transportation options, and busier schedules in the United States. Interviewees also identified a sudden increase in access to unhealthy food and an abrupt reduction in access to, and affordability of, healthy food choices upon immigration. Culturally appropriate interventions to increase awareness of these factors and neutralize their effects among early Latino immigrants are recommended.展开更多
In this paper,we consider a critical Galton-Watson branching process with immigration stopped at zero W.Some precise estimation on the probability generating function of the n-th population are obtained,and the tail p...In this paper,we consider a critical Galton-Watson branching process with immigration stopped at zero W.Some precise estimation on the probability generating function of the n-th population are obtained,and the tail probability of the life period of W is studied.Based on above results,two conditional limit theorems for W are established.展开更多
This paper establishes an age-structured Tuberculosis(TB)model to investigate the joint impacts of information and immigration of population on the spread of TB disease.Mathematically,we show that the model is point d...This paper establishes an age-structured Tuberculosis(TB)model to investigate the joint impacts of information and immigration of population on the spread of TB disease.Mathematically,we show that the model is point dissipative,and the semi-flow generated by the model has the property of asymptotic smoothness,and then study the existence and global stability of positive steady state by the direct Lyapunov functional.Numerically,by using Matlab software,we verify the theoretical results,and further explore the influence of information(including information coverage and disease-related memory delay)and immigration on the final size of TB disease.The simulation results show that both information coverage and immigration are positive correlated with the final size of disease,and disease-related memory delay can affect the arrival time of positive steady state,which implies us that improving information coverage,enlarging disease-related memory,and reducing the immigration of population(especially latent and infected individuals)can effectively control the progression of TB disease.展开更多
The aerial manipulator expands the scope of unmanned aerial vehicle(UAV)'s application as well as increases the di±culties in the design of the controller.To better control the aerial manipulator for di®...The aerial manipulator expands the scope of unmanned aerial vehicle(UAV)'s application as well as increases the di±culties in the design of the controller.To better control the aerial manipulator for di®erent trajectories tracking under di®erent conditions,a new dual-layer controller is designed in this paper.The integral backstepping sliding mode controller(IBSMC)is applied to the outer-loop controller and backstepping controller(BC)is applied to the innerloop controller.To improve the performance of the system,an improved pigeon-inspired optimization(PIO)algorithm called group coevolution and immigration pigeon-inspired optimization(GCIPIO)algorithm is proposed to optimize the controller parameters of IBSMC.GCIPIO algorithm utilizes the group coevolution and immigration mechanisms.A series of simulations are conducted to show the advantage of the proposed method.The results illustrate that the proposed method ensures the closed-loop system has less end-e®ector tracking error.展开更多
This paper presents the results of a research project on the intercultural climate in schools and the academic success of immigrant students in Quebec.The intercultural climate in eight secondary public schools is doc...This paper presents the results of a research project on the intercultural climate in schools and the academic success of immigrant students in Quebec.The intercultural climate in eight secondary public schools is documented from the standpoint of various school and community stakeholders,students,and parents.More specifically,the paper focuses on the commitment to promoting cultural equity,which is identified through interviews with the targeted stakeholders on exclusionary practices and processes and the practices implemented to counter them.The results identify five areas of vulnerability among certain minoritized groups of students:the transition from welcoming to regular classes for those students learning French,evaluation and support for those experiencing learning or behavioral difficulties,the referral of these students to adult education programs or work-oriented training programs,their participation in extracurricular activities,and their access to special school projects.Nonetheless,some schools do report the introduction of many equity practices in response to the exclusionary ones.However,these initiatives are mostly occasional and voluntary and pertain to interactions between individuals.These findings call for a discussion on the importance of systemic and concerted initiatives towards achieving equity.展开更多
In recent years,Francophone schools in Alberta,a province in western Canada,have seen significant ethnocultural diversification of their school population,thus reflecting recent migratory changes in Canada.The populat...In recent years,Francophone schools in Alberta,a province in western Canada,have seen significant ethnocultural diversification of their school population,thus reflecting recent migratory changes in Canada.The population of a Francophone school board located in an agglomeration of Alberta reflects these new migratory trends.A partial ethnodemographic portrait carried out in 2003 in six of its schools indicates that 50%of the pupils come from an immigrant background and come from 23 different countries;mostly from sub-Saharan African countries.This demographic reality,confirmed more than a decade later,represents a major structural change for Francophone schools.In Alberta,as in other Canadian provinces,inclusion is at the heart of discourse and educational practices.With a transformative aim,it intends to promote ethnocultural diversity in the classroom and equal opportunities through school equity practices.This article focuses on the settlement workers in schools responsible for bridging family,community,and school cultures.The analysis of the interviews of the four workers sheds light on and questions both the institutional practices and the personal strategies put in place to face the challenges encountered in this tripartite collaboration.展开更多
The school placement processes of students from immigrant backgrounds considered to be in“difficulty”is an international concern at the intersection of works relating to special education and those concerning the sc...The school placement processes of students from immigrant backgrounds considered to be in“difficulty”is an international concern at the intersection of works relating to special education and those concerning the school experiences of students from immigrant backgrounds or racialized groups.The research problem of this article concerns the identification of these students as disabled or as having adjustment or learning difficulties.From a perspective anchored in Disability Critical Race Studies,this ethnographic study documents different interpretations of perceived difficulties made by school actors with regard to seven primary school students from immigrant backgrounds.Five interpretation types are presented:(1)medicalization by dismissal of cultural markers,(2)medicalization by professional constraint,(3)medicalization by cultural deficit,(4)precautionary wait,and(5)cultural differentialism.Our results help to shed light on the special education overrepresentation phenomenon regarding these students and to understand how ableism and(neo)racism contribute to it.展开更多
We prove a moderate deviation principle for a super-Brownian motion with immigration of all dimensions, and consequently fill the gap between the central limit theorem and large deviation principle.
We consider a modified Markov branching process incorporating with both state-independent immigration and instantaneous resurrection.The existence criterion of the process is firstly considered.We prove that if the su...We consider a modified Markov branching process incorporating with both state-independent immigration and instantaneous resurrection.The existence criterion of the process is firstly considered.We prove that if the sum of the resurrection rates is finite,then there does not exist any process.An existence criterion is then established when the sum of the resurrection rates is infinite.Some equivalent criteria,possessing the advantage of being easily checked,are obtained for the latter case.The uniqueness criterion for such process is also investigated.We prove that although there exist infinitely many of them,there always exists a unique honest process for a given q-matrix.This unique honest process is then constructed.The ergodicity property of this honest process is analysed in detail.We prove that this honest process is always ergodic and the explicit expression for the equilibrium distribution is established.展开更多
基金supported by Shaanxi Agricultural Collaborative Innovation and Promotion Alliance Foundation (Grant No. LM20150015)Shaanxi Key Theoretical & Realistic Projects of Social Science Research Foundation (Grant No. 2015Z023)
文摘Immigration relocation of the poor in rural areas is an effective targeted measure to help people out of poverty in the new normal. The structural constraints lie in the heavy pressure of land resources and environmental carrying capacity, high cost of immigration settlement and delayed counterpart funds, insufficient industrial support and difficulty in living-making. To realize the goal of targeted poverty alleviation, it demands determination and capability from the policy designer, as well the social basis. The effect imposed by the structural constraints to implementation of such policy should be paid adequate attention by public sectors. It is supposed to change the guiding direction of the policy timely and to relieve financial burden of immigration settlement and resource environmental bearing capacity through mechanism of joint efforts from internal and more external support.
文摘In 1994, the total Chinese population in the United States were 2,017,799 which were 0.8 percent of the total US population. The Chinese population were highly concentrated by regions and among the total population. By states, 42 percent of total Chinese population were found in California, 17 percent in New York. More than 80 percent total Chinese population were concentrated in 9 states. By metropolitan areas, 14.73 percent of total Chinese population were found in Los Angeles and New York respectively. Compared with the total US population, 60 percent Chinese population were found in less than 20 percent total US population and 80 percent in 50 percent. By studying the Chinese population distribution and the reason behind it, we hope to find some interesting relationships among the characteristics of this distribution and the historical, cultural, social and economic factors influencing it.
基金partially supported by the National Nature Science Foundation of China(11601286,11501146)。
文摘Let(Z_(n))be a branching process with immigration in a random environmentξ,whereξis an independent and identically distributed sequence of random variables.We show asymptotic properties for all the moments of Z_(n) and describe the decay rates of the n-step transition probabilities.As applications,a large deviation principle for the sequence log Z_(n) is established,and related large deviations are also studied.
基金supported by the National Natural Science Foundation of China(11571052,11731012)the Hunan Provincial Natural Science Foundation of China(2018JJ2417)the Open Fund of Hunan Provincial Key Laboratory of Mathematical Modeling and Analysis in Engineering(2018MMAEZD02)。
文摘We are interested in the convergence rates of the submartingale Wn=Z_(n)/Π_(n)to its limit W,where(Π_(n))is the usually used norming sequence and(Z_(n))is a supercritical branching process with immigration(Y_(n))in a stationary and ergodic environmentξ.Under suitable conditions,we establish the following central limit theorems and results about the rates of convergence in probability or in law:(i)W-W_(n) with suitable normalization converges to the normal law N(0,1),and similar results also hold for W_(n+k)-W_(n) for each fixed k∈N^(*);(ii)for a branching process with immigration in a finite state random environment,if W_(1) has a finite exponential moment,then so does W,and the decay rate of P(|W-W_(n)|>ε)is supergeometric;(iii)there are normalizing constants an(ξ)(that we calculate explicitly)such that a_(n)(ξ)(W-W_(n))converges in law to a mixture of the Gaussian law.
基金Humanities and Social Science Research Planning Fund of the Education Ministry of China(No.15YJCZH2010)the Research Innovation Program of Shanghai Municipal Education Commission,China(No.14YZ134)Shanghai 085 Project for Municipal Universities,China
文摘A kind of stochastic susceptible-exposed but not infectiousinfectious-removed (SEIR) model with constant immigration in incubation period is presented, based on a deterministic SEIR model, via the technique of parameter perturbation which is standard in stochastic population modeling. The influence of the environmental noise as a standard Gaussian white noise on the epidemics' transmission is studied. Furthermore,the condition for the epidemics' persistence is obtained by formulating the corresponding function and using It 's formula. And the asymptotic behavior of the model near the endemic disease equilibrium is also studied. In this way, the decision support is provided in the application of this kind of stochastic SEIR model on the epidemics' prevention and control.
文摘In order to find out the effect of human (sexual) behavior change and immigration in spreading the HIV/AIDS, a deterministic model of HIV/AIDS with infective immigration is formulated. First, basic properties of the model, including non-negativity and boundedness of the solutions, existence of the endemic equilibrium and the basic reproduction number, R0 are analyzed. The geometrical approach is used to obtain the global asymptotic stability of endemic equilibrium. Then the basic model is extended to include several control efforts aimed at reducing infection and changing behavior. Pontryagin’s maximum principle is used to derive the optimality system and solve the system numerically. Our numerical findings are illustrated through simulations using MATLAB, which shows reliability of our model from the practical point of view.
基金supported by the National Social Science Fond of China(Grant No.13XSH031)Shaanxi Key Theoretical & Realistic Projects of Social Science Research Foundation(Grant No.2015Z023)+1 种基金Shaanxi Agricultural Collaborative Innovation and Promotion Alliance Foundation(Grant No.LM2015015)the Fundamental Research Funds for the Central Universities(Grant No.2013RWYB09)
文摘Immigration issue is one of the major problems in China today.The implementation of disasterinduced immigration policy is a significant contributor to effectively promote targeted measures of helping people in contiguous poor areas with particular difficulties to be out of poverty.Empirical investigation has been conducted to get a systematic grasp of the implementation deviation of massive disaster-induced immigration phenomenon in southern Shaanxi area.According to the survey,phenomenon of "immigrate the rich,while abandoning the poor,more houses with fewer immigrants,four moves and four drops,poor spot choosing and relaxed project management" demands improvement of execution ability.The implementation of such public policy has a large space to improve.Enough attention should be paid to the negative impact of such deviation,and only in this way can we live up to the desired objectives.
文摘The new immigration policies introduced by Trump administration have saturated the world's screens,which have gained a mixed reception from the higher education circles amid considerable controversy,exacerbating the plight of the brain drains,hurting the enthusiasm of those who have a strong desire to live in the USA,particularly the college leavers,and triggering a decline in the quality of education for foreign students,which could be a game-changer in the competition pattern of higher education and loom large.On this occasion,in matters of China,some more robust methodologies are to jump at the chance,attract qualified personnel and present some more aggressive human resources strategies.
基金the Instituto de Ciencias del Mar y Limnologia(UNAM)for the financing of this project
文摘Immigration density magnitude and entry sizes of shrimp postlarvae to Terminos Lagoon were analyzed through sixteen fortnightly sampling from March to November in 2013, in three levels in the deepest channel of the Puerto Real inlet. Trapezium nets were used with 1.5 m length, 50 cm mouth diameter and 505 μm mesh, during each sampling 12 casts of 15 minutes/each were made. It was determined the presence of two species Litopenaeus setiferus and Farfantepenaeus duorarum, with total densities of 41.284 and 37.558 Pls 100 m-3 respectively. The annual cycle of immigration of postlarvae was very similar for both species, with a clear pattern of immigration throughout the year, linked to climatic variation, with the highest densities (88%) during rainy season. There were two periods of maximum density, related to the periods of greatest reproduction of these species. The density variation among cast reflects the presence of at least two and probably more postlarvae banks, located some closer than others to the mouth of the lagoon and with different densities in them. The average sizes of the two species were 7.9 mm total length of L. setiferus and 9.0 mm of F. duorarum. The differences in income sizes of both species seem to indicate the habitat preference of adult populations, L. setiferus occurring in more coastal areas than F. duorarum. Considering the variation in density and sizes throughout each sampling period, it is evident that the larvae on the banks belong to different cohorts and that have coincided in their location in front of the mouth.
基金National Science Foundation of China(41075086,41475106)Science Research Program of Universities and Colleges in Jiangsu Province(14KJA170003)Priority Academic Program Development of Jiangsu Higher Education Institutions(IRT1147)
文摘Various features of the atmospheric environment affect the number of migratory insects, besides their initial population. However, little is known about the impact of atmospheric low-frequency oscillation(10 to 90 days) on insect migration. A case study was conducted to ascertain the influence of low-frequency atmospheric oscillation on the immigration of brown planthopper, Nilaparvata lugens(Stl), in Hunan and Jiangxi provinces. The results showed the following:(1) The number of immigrating N. lugens from April to June of 2007 through 2016 mainly exhibited a periodic oscillation of 10 to 20 days.(2) The 10-20 d low-frequency number of immigrating N. lugens was significantly correlated with a low-frequency wind field and a geopotential height field at 850 h Pa.(3) During the peak phase of immigration, southwest or south winds served as a driving force and carried N. lugens populations northward, and when in the back of the trough and the front of the ridge, the downward airflow created a favorable condition for N. lugens to land in the study area. In conclusion, the northward migration of N. lugens was influenced by a low-frequency atmospheric circulation based on the analysis of dynamics. This study was the first research connecting atmospheric low-frequency oscillation to insect migration.
文摘US Latinos experience higher rates of obesity than their non-Latino counterparts. Factors associated with immigration, including length of residence in the United States, are associated with an increased risk of obesity. Latino community health workers (CHWs) work closely with communities, and are in an ideal position to provide insight on the underlying mechanisms of the Latino obesity epidemic. Focus groups were conducted with 15 CHWs and thematic analyses were performed to explore elements associated with obesity among Latino immigrants. Emergent themes included: reduction in physical activity due to less walkable spaces, more transportation options, and busier schedules in the United States. Interviewees also identified a sudden increase in access to unhealthy food and an abrupt reduction in access to, and affordability of, healthy food choices upon immigration. Culturally appropriate interventions to increase awareness of these factors and neutralize their effects among early Latino immigrants are recommended.
基金supported by China Postdoctoral Science Foundation(Grant No.2020M680269)National Natural Science Foundation of China(Grant No.12101023)+1 种基金the second author is supported by National Natural Science Foundation of China(Grant No.11871103)the National Key Research and Development Program of China(Grant No.2020YFA0712900)。
文摘In this paper,we consider a critical Galton-Watson branching process with immigration stopped at zero W.Some precise estimation on the probability generating function of the n-th population are obtained,and the tail probability of the life period of W is studied.Based on above results,two conditional limit theorems for W are established.
基金the anonymous referees for their careful reading and helpful comments which led to an improvement of our paper.This work was supported by National Natural Science Foundation of China(Nos.12126349,11601293,11901326,11901477)the Natural Science Foundation of Shanxi Province(No.201901D211160)+1 种基金the Natural Science Foundation of Guizhou Province(No.Qian Ke He Jichu-ZK[2021]Yiban002)the Project funded by China Postdoctoral Science Foundation(2019M653816XB).
文摘This paper establishes an age-structured Tuberculosis(TB)model to investigate the joint impacts of information and immigration of population on the spread of TB disease.Mathematically,we show that the model is point dissipative,and the semi-flow generated by the model has the property of asymptotic smoothness,and then study the existence and global stability of positive steady state by the direct Lyapunov functional.Numerically,by using Matlab software,we verify the theoretical results,and further explore the influence of information(including information coverage and disease-related memory delay)and immigration on the final size of TB disease.The simulation results show that both information coverage and immigration are positive correlated with the final size of disease,and disease-related memory delay can affect the arrival time of positive steady state,which implies us that improving information coverage,enlarging disease-related memory,and reducing the immigration of population(especially latent and infected individuals)can effectively control the progression of TB disease.
基金the Science and Technology Innovation 2030-Key Project of\New Generation Articial Intelligence"under grant#2018AAA0102403National Natural Science Foundation of China under grant#U20B2071,#91948204,#T2121003,#U1913602 and#U19B2033.
文摘The aerial manipulator expands the scope of unmanned aerial vehicle(UAV)'s application as well as increases the di±culties in the design of the controller.To better control the aerial manipulator for di®erent trajectories tracking under di®erent conditions,a new dual-layer controller is designed in this paper.The integral backstepping sliding mode controller(IBSMC)is applied to the outer-loop controller and backstepping controller(BC)is applied to the innerloop controller.To improve the performance of the system,an improved pigeon-inspired optimization(PIO)algorithm called group coevolution and immigration pigeon-inspired optimization(GCIPIO)algorithm is proposed to optimize the controller parameters of IBSMC.GCIPIO algorithm utilizes the group coevolution and immigration mechanisms.A series of simulations are conducted to show the advantage of the proposed method.The results illustrate that the proposed method ensures the closed-loop system has less end-e®ector tracking error.
文摘This paper presents the results of a research project on the intercultural climate in schools and the academic success of immigrant students in Quebec.The intercultural climate in eight secondary public schools is documented from the standpoint of various school and community stakeholders,students,and parents.More specifically,the paper focuses on the commitment to promoting cultural equity,which is identified through interviews with the targeted stakeholders on exclusionary practices and processes and the practices implemented to counter them.The results identify five areas of vulnerability among certain minoritized groups of students:the transition from welcoming to regular classes for those students learning French,evaluation and support for those experiencing learning or behavioral difficulties,the referral of these students to adult education programs or work-oriented training programs,their participation in extracurricular activities,and their access to special school projects.Nonetheless,some schools do report the introduction of many equity practices in response to the exclusionary ones.However,these initiatives are mostly occasional and voluntary and pertain to interactions between individuals.These findings call for a discussion on the importance of systemic and concerted initiatives towards achieving equity.
文摘In recent years,Francophone schools in Alberta,a province in western Canada,have seen significant ethnocultural diversification of their school population,thus reflecting recent migratory changes in Canada.The population of a Francophone school board located in an agglomeration of Alberta reflects these new migratory trends.A partial ethnodemographic portrait carried out in 2003 in six of its schools indicates that 50%of the pupils come from an immigrant background and come from 23 different countries;mostly from sub-Saharan African countries.This demographic reality,confirmed more than a decade later,represents a major structural change for Francophone schools.In Alberta,as in other Canadian provinces,inclusion is at the heart of discourse and educational practices.With a transformative aim,it intends to promote ethnocultural diversity in the classroom and equal opportunities through school equity practices.This article focuses on the settlement workers in schools responsible for bridging family,community,and school cultures.The analysis of the interviews of the four workers sheds light on and questions both the institutional practices and the personal strategies put in place to face the challenges encountered in this tripartite collaboration.
文摘The school placement processes of students from immigrant backgrounds considered to be in“difficulty”is an international concern at the intersection of works relating to special education and those concerning the school experiences of students from immigrant backgrounds or racialized groups.The research problem of this article concerns the identification of these students as disabled or as having adjustment or learning difficulties.From a perspective anchored in Disability Critical Race Studies,this ethnographic study documents different interpretations of perceived difficulties made by school actors with regard to seven primary school students from immigrant backgrounds.Five interpretation types are presented:(1)medicalization by dismissal of cultural markers,(2)medicalization by professional constraint,(3)medicalization by cultural deficit,(4)precautionary wait,and(5)cultural differentialism.Our results help to shed light on the special education overrepresentation phenomenon regarding these students and to understand how ableism and(neo)racism contribute to it.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.10071008 and 10121101).
文摘We prove a moderate deviation principle for a super-Brownian motion with immigration of all dimensions, and consequently fill the gap between the central limit theorem and large deviation principle.
基金partially supported by the National Natural Science Foundation of China (Grant No. 10771216)Research Grants Council of Hong Kong (Grant No. HKU 7010/06P)Project-sponsored by SRF for ROCS,SEM
文摘We consider a modified Markov branching process incorporating with both state-independent immigration and instantaneous resurrection.The existence criterion of the process is firstly considered.We prove that if the sum of the resurrection rates is finite,then there does not exist any process.An existence criterion is then established when the sum of the resurrection rates is infinite.Some equivalent criteria,possessing the advantage of being easily checked,are obtained for the latter case.The uniqueness criterion for such process is also investigated.We prove that although there exist infinitely many of them,there always exists a unique honest process for a given q-matrix.This unique honest process is then constructed.The ergodicity property of this honest process is analysed in detail.We prove that this honest process is always ergodic and the explicit expression for the equilibrium distribution is established.
