Hainanese Chicken Rice This is a must-try dish in Singapore.The name comes from the Hainanese immigrants who came to Singapore and adapted their dish,making it better to suit local tastes.If you only have one day,make...Hainanese Chicken Rice This is a must-try dish in Singapore.The name comes from the Hainanese immigrants who came to Singapore and adapted their dish,making it better to suit local tastes.If you only have one day,make sure eating Hainanese chicken rice is on your to-do list.At a good chicken rice restaurant,you can enjoy perfectly cooked chicken and tasty rice.Egg and tofu are highly recommended and they will add to the experience.展开更多
This study sought to analyze the occupational habits of immigrant workers in the formal Brazilian labor market from a sociological perspective.It was understood that a study on occupation should observe professional a...This study sought to analyze the occupational habits of immigrant workers in the formal Brazilian labor market from a sociological perspective.It was understood that a study on occupation should observe professional and employment history,which may include an analysis over time of workers in the same profession or in periods of professional mobility.In order to understand occupational trajectories and related aspects,this study used data that were collected through semi-structured interviews and surveys with immigrant workers who were employed in the Brazilian formal labor market.The interviews and surveys revealed a strong polarization among the immigrant workers present in Brazil-while a small part holds highly skilled occupations,the majority participate at the base of the productivity hierarchy.展开更多
INTRODUCTION Reports indicating that culturally and linguistically diverse(CALD)people-often with migrant backgrounds-in Australia and New Zealand are more likely to be placed in compulsory community treatment(CCT)hav...INTRODUCTION Reports indicating that culturally and linguistically diverse(CALD)people-often with migrant backgrounds-in Australia and New Zealand are more likely to be placed in compulsory community treatment(CCT)have rightlyraised concernsthat such action might be discriminatory.展开更多
Background:Against the backdrop of the complex interplay between global migration flows and the European Union’s governance system,immigrants’subjective well-being(SWB)has become a crucial indicator for assessing bo...Background:Against the backdrop of the complex interplay between global migration flows and the European Union’s governance system,immigrants’subjective well-being(SWB)has become a crucial indicator for assessing both their social integration and the effectiveness of integration policies.However,few studies have systematically linked immigration law and policy to SWB through a structured framework of human needs.This study aims to assess how European Union(EU)immigration policies influence immigrants’SWB by facilitating the fulfillment of hierarchical needs based on Maslow’s theory.Methods:Using data from the European Social Survey(ESS,2010–2023),this study analyzed 28,854 first-generation and second-generation immigrants across 24 EU member states.This study employed hierarchical regression models to assess the relative contribution of five levels of needs-physiological,safety,social,esteem,and self-actualization-in predicting life satisfaction and happiness,controlling for sociodemographic factors.Results:Safety needs-comprising perceived safety and institutional trust-produced the largest model improvement(ΔR^(2)≈0.06–0.07).Physiological needs(stable income and self-rated health)also had significant positive effect(β=0.06–0.25,p<0.001).Social and esteem needs showed moderate associations(β≈0.09–0.17,p<0.001),while self-actualization needs(education and union membership)displayed generational variation(β=0.02–0.10,p<0.01).Conclusion:This study not only validates the applicability of Maslow’s theory in migration research but also empirically establishes a policy hierarchy:ensuring physiological and safety needs as a foundation,supporting social and esteem needs,and enabling self-actualization pathways are essential for enhancing immigrant well-being.The findings offer valuable theoretical insights and practical guidance for refining immigrant integration policies within the EU’s multi-level governance structure.展开更多
The city of São Paulo in Brazil has many Japanese restaurants.Meanwhile,in Hamamatsu,Japan,there are also many places to eat Brazilian food.Why is each country’s food so popular in the other?The answer goes back...The city of São Paulo in Brazil has many Japanese restaurants.Meanwhile,in Hamamatsu,Japan,there are also many places to eat Brazilian food.Why is each country’s food so popular in the other?The answer goes back to the early 20th century.展开更多
With blended learning emerging as a mainstream paradigm in higher education,the Document Security Technology course faces persistent challenges,including vague instructional objectives and low learning efficiency.Simu...With blended learning emerging as a mainstream paradigm in higher education,the Document Security Technology course faces persistent challenges,including vague instructional objectives and low learning efficiency.Simultaneously,the profession demands stronger self-directed learning capabilities from practitioners.To address these issues,this study develops a“Five-in-One”self-directed learning model comprising five interrelated dimensions:goal orientation,instructional regulation,cognitive development,technological resources,and process monitoring.The application of this model has significantly improved course evaluation outcomes,enhanced faculty teaching and research capacity,strengthened students’practical and innovative skills,and expanded the course’s reach and social impact.The model thus provides both a theoretical framework and a practical pathway for the reform of similar applied courses.展开更多
After Donald Trump returned to the White House,the U.S.government launched a host of measures of“tariff wars”.In addition to announcing tariffs on goods imported to the United States from Canada,Mexico and China,the...After Donald Trump returned to the White House,the U.S.government launched a host of measures of“tariff wars”.In addition to announcing tariffs on goods imported to the United States from Canada,Mexico and China,the government also imposed trade restrictions on specific industries including steel,aluminum and copper,as well as advanced plan for“reciprocal tariffs”.Donald Trump claimed that a“tariff war”would correct trade imbalances,boost government revenue and promote the reshoring of manufacturing to the United States.By leveraging tariffs,the U.S.also attempts to achieve goals in border security,illegal immigration and fentanyl control.Undoubtedly at a central position in Trump’s second term in office,the“tariff war”will exert impacts far beyond economic and trade policies and upon the direction of China-U.S.relations.展开更多
Hu Junhui,president of Tianfu Association(Singapore)and recipient of the Public Service Medal(PBM),has been leading community efforts to help new Chinese immigrants integrate into Singaporean society.Originally from H...Hu Junhui,president of Tianfu Association(Singapore)and recipient of the Public Service Medal(PBM),has been leading community efforts to help new Chinese immigrants integrate into Singaporean society.Originally from Hebei Province in China,Hu arrived in Singapore in 1994 as one of the first technical professionals dispatched by China.Since then,he has built a life and career firmly rooted in Singapore.Over more than four years at China Construction(South Pacific)Development Co Pte Ltd,he rose through the ranks from project engineer to site manager and eventually project director.In 1999,he left the company to start his own business,setting up a construction firm with several partners.His focus shifted to real estate in 2007,when he co-founded JVA Venture Pte Ltd.展开更多
Against the backdrop of the 35th anniversary of China-Singapore diplomatic relations,Tianfu Association(Singapore)has emerged as a key force fostering closer people-to-people and economic ties between the two countrie...Against the backdrop of the 35th anniversary of China-Singapore diplomatic relations,Tianfu Association(Singapore)has emerged as a key force fostering closer people-to-people and economic ties between the two countries.Founded in January 2000 by a group of new immigrants from China’s Sichuan Province,the association was the first Chinese immigrant organization established after diplomatic ties were formed between Singapore and China.Over the past two decades,it has actively engaged in local affairs and now serves as a council member of the Singapore Federation of Chinese Clan Associations.Today,it is widely recognized as one of the most vibrant and influential new immigrant groups promoting integration into Singaporean society.展开更多
We study age-structured branching models with reproduction law depending on the remaining lifetime of the parent. The lifespan of an individual is determined at its birth and its remaining lifetime decreases at the un...We study age-structured branching models with reproduction law depending on the remaining lifetime of the parent. The lifespan of an individual is determined at its birth and its remaining lifetime decreases at the unit speed. The models, without or with immigration, are constructed as measure-valued processes by pathwise unique solutions of stochastic equations driven by time-space Poisson random measures. In the subcritical branching case, we give a sufficient condition for the ergodicity of the process with immigration. Two large number laws and a central limit theorem of the occupation times are proved.展开更多
Based on field survey and research of Hanzhong, relocation of Nanzheng County was explored and the existing problems were analyzed. Furthermore, the re- gional characters of Nanzheng County were investigated to analyz...Based on field survey and research of Hanzhong, relocation of Nanzheng County was explored and the existing problems were analyzed. Furthermore, the re- gional characters of Nanzheng County were investigated to analyze the feasibility and necessity of relocation with lots of data and evaluation was made on relocation of Nanzheng County. In addition, the existing problems of relocation were concluded and the prospect of the county was discussed, which is of significance for relocation in Nanzheng County and even southern Shaanxi Province.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
In 1971 the government of Canada adopted the policy of multiculturalism. Since then Canada has become the first western country to announce and implement an official policy of multiculturalism. While it is not easy to...In 1971 the government of Canada adopted the policy of multiculturalism. Since then Canada has become the first western country to announce and implement an official policy of multiculturalism. While it is not easy to achieve this policy. The policies seem just to strengthen the racial consciousness in some extent, and the immigrant groups have to tackle the problem of how to fuse into the Canadian culture. Multiculturalism will have a bright future only if it would experience constant adjustment and improvement.展开更多
Dynamic optimization problems are a kind of optimization problems that involve changes over time. They pose a serious challenge to traditional optimization methods as well as conventional genetic algorithms since the ...Dynamic optimization problems are a kind of optimization problems that involve changes over time. They pose a serious challenge to traditional optimization methods as well as conventional genetic algorithms since the goal is no longer to search for the optimal solution（s） of a fixed problem but to track the moving optimum over time. Dynamic optimization problems have attracted a growing interest from the genetic algorithm community in recent years. Several approaches have been developed to enhance the performance of genetic algorithms in dynamic environments. One approach is to maintain the diversity of the population via random immigrants. This paper proposes a hybrid immigrants scheme that combines the concepts of elitism, dualism and random immigrants for genetic algorithms to address dynamic optimization problems. In this hybrid scheme, the best individual, i.e., the elite, from the previous generation and its dual individual are retrieved as the bases to create immigrants via traditional mutation scheme. These elitism-based and dualism-based immigrants together with some random immigrants are substituted into the current population, replacing the worst individuals in the population. These three kinds of immigrants aim to address environmental changes of slight, medium and significant degrees respectively and hence efficiently adapt genetic algorithms to dynamic environments that are subject to different severities of changes. Based on a series of systematically constructed dynamic test problems, experiments are carried out to investigate the performance of genetic algorithms with the hybrid immigrants scheme and traditional random immigrants scheme. Experimental results validate the efficiency of the proposed hybrid immigrants scheme for improving the performance of genetic algorithms in dynamic environments.展开更多
Two sequencing batch reactors（SBRs） were operated for 100 days under aerobic conditions,with one being fed with unsterilized municipal wastewater（USBR）, and the other fed with sterilized municipal wastewater（SSBR...Two sequencing batch reactors（SBRs） were operated for 100 days under aerobic conditions,with one being fed with unsterilized municipal wastewater（USBR）, and the other fed with sterilized municipal wastewater（SSBR）. Respirometric assays and fluorescence in situ hybridization（FISH） results show that active nitrifiers were present in the unsterilized influent municipal wastewater. The maximum ammonia utilization rate（AUR） and nitrite utilization rate（NUR） of the unsterilized influent were 0.32 ± 0.12 mg NH4＋-N/（L·hr） and0.71 ± 0.18 mg NO2--N/（L·hr）. Based on the maximum utilization rates, the estimated seeding intensity for the ammonia oxidizing bacteria（AOB） and nitrite oxidizing bacteria（NOB） of the USBR was 0.08 g AOB/（g AOB·day） and 0.20 g NOB/（g NOB·day） respectively. The fraction of nitrifiers/total bacteria in the influent was 5.35% ± 2.1%, the dominant AOB was Nitrosomonas spp., Nitrosococcus mobilis hybridizated with Nsm156, and the dominant NOB was Nitrospira hybridizated with Ntspa662. The influent nitrifiers potentially seeded the activated sludge of the bioreactor and hence demonstrated a mitigation of the acclimatization times and instability during start-up and early operation. The AUR and NUR in the USBR was 15% and 13% higher than the SSBR respectively during the stable stage, FISH results showed that nitrifiers population especially the Nitrospira in the USBR was higher than that in the SSBR. These results indicate that the natural continuous immigration of nitrifiers from municipal influent streams may have some repercussions on the modeling and design of bioreactors.展开更多
Organic and inorganic materials migrate downstream and have important roles in regulating environmental health in the river networks.However,it remains unclear whether and how a mixture of materials(i.e.,microbial spe...Organic and inorganic materials migrate downstream and have important roles in regulating environmental health in the river networks.However,it remains unclear whether and how a mixture of materials(i.e.,microbial species)from various upstream habitats contribute to microbial community coalescence upstream of a dam.Here we track the spatial variation in microbial abundance and diversity in the Three Gorges Reservoir based on quantitative PCR and 16 S rRNA gene high-throughput sequencing data.We further quantitatively assess the relative contributions of microbial species from mainstem,its tributaries,and the surrounding riverbank soils to the area immediately upstream of the Three Gorges Dam(TGD).We found an increase of microbial diversity and the convergent microbial distribution pattern in areas immediately upstream of TGD,suggesting this area become a new confluence for microbial diversity immigrating from upstream.Indeed,the number of shared species increased from upstream to TGD but unique species decreased,indicating immigration of various sources of microbial species overwhelms local environmental conditions in structuring microbial community close to TGD.By quantifying the sources of microbial species close to TGD,we found little contribution from soils as compared to tributaries,especially for sites closer to TGD,suggesting tributary microbes have greater influence on microbial diversity and environmental health in the Three Gorges Reservoir.Collectively,our results suggest that tracking microbial geographic origin and evaluating accumulating effects of microbial diversity shed light on the ecological processes in microbial communities and provide information for regulating aquatic ecological health.展开更多
Hepatitis B virus(HBV) is the most common cause of hepatitis worldwide, with nearly 350 million people chronically infected and 600000 deaths per year due to acute liver failure occurring during acute hepatitis or, mo...Hepatitis B virus(HBV) is the most common cause of hepatitis worldwide, with nearly 350 million people chronically infected and 600000 deaths per year due to acute liver failure occurring during acute hepatitis or, more frequently, in HBV-related liver cirrhosis or hepatocellular carcinoma. Ongoing immigration from countries with a high HBV endemicity to those with a low HBV endemicity warrants particular attention to prevent the spread of HBV infection to the native population. This review article analyzes the epidemiology and virological and clinical characteristics of HBV infection in immigrant populations and in their host countries, and suggests prophylactic measures to prevent the spread of this infection. Among the immigrants from different geographical areas, those from South East Asia and sub-Saharan Africa show the highest prevalences of hepatitis B surface antigen(HBs Ag) carriers, in accordance with the high endemicity of the countries of origin. The molecular characteristics of HBV infection in immigrants reflect those of the geographical areas of origin: HBV genotype A and D predominate in immigrants from Eastern Europe, B and C in those from Asia and genotype E in those from Africa. The literature data on the clinical course and treatment of HBs Agpositive immigrants are scanty. The management of HBV infection in immigrant populations is difficult and requires expert personnel and dedicated structures for their assistance. The social services, voluntary operators and cultural mediators are essential to achieve optimized psychological and clinical intervention.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
T cells play a critical role in immunity to protect against pathogens and malignant cells.T cell immunodeficiency is detrimental,especially when T cell perturbation occurs during severe infection,irradiation,chemother...T cells play a critical role in immunity to protect against pathogens and malignant cells.T cell immunodeficiency is detrimental,especially when T cell perturbation occurs during severe infection,irradiation,chemotherapy,and age-related thymic atrophy.Therefore,strategies that enhance T cell reconstitution provide considerable benefit and warrant intensive investigation.Here,we report the construction of a T cell ablation model in Tg(coro1a:Den NTR)zebrafish via metronidazole administration.The nascent T cells are mainly derived from the hematopoietic cells migrated from the kidney,the functional homolog of bone marrow and the complete recovery time is 6.5 days post-treatment.The cxcr4b gene is upregulated in the responsive hematopoietic cells.Functional interference of CXCR4 via both genetic and chemical manipulations does not greatly affect T lymphopoiesis,but delays T cell regeneration by disrupting hematopoietic migration.In contrast,cxcr4b accelerates the replenishment of hematopoietic cells in the thymus.Consistently,Cxcl12b,a ligand of Cxcr4,is increased in the thymic epithelial cells of the injured animals.Decreased or increased expression of Cxcl12b results in compromised or accelerated T cell recovery,respectively,similar to those observed with Cxcr4b.Taken together,our study reveals a role of CXCR4-CXCL12 signaling in promoting T cell recovery and provides a promising target for the treatment of immunodeficiency due to T cell injury.展开更多
文摘Hainanese Chicken Rice This is a must-try dish in Singapore.The name comes from the Hainanese immigrants who came to Singapore and adapted their dish,making it better to suit local tastes.If you only have one day,make sure eating Hainanese chicken rice is on your to-do list.At a good chicken rice restaurant,you can enjoy perfectly cooked chicken and tasty rice.Egg and tofu are highly recommended and they will add to the experience.
文摘This study sought to analyze the occupational habits of immigrant workers in the formal Brazilian labor market from a sociological perspective.It was understood that a study on occupation should observe professional and employment history,which may include an analysis over time of workers in the same profession or in periods of professional mobility.In order to understand occupational trajectories and related aspects,this study used data that were collected through semi-structured interviews and surveys with immigrant workers who were employed in the Brazilian formal labor market.The interviews and surveys revealed a strong polarization among the immigrant workers present in Brazil-while a small part holds highly skilled occupations,the majority participate at the base of the productivity hierarchy.
文摘INTRODUCTION Reports indicating that culturally and linguistically diverse(CALD)people-often with migrant backgrounds-in Australia and New Zealand are more likely to be placed in compulsory community treatment(CCT)have rightlyraised concernsthat such action might be discriminatory.
文摘Background:Against the backdrop of the complex interplay between global migration flows and the European Union’s governance system,immigrants’subjective well-being(SWB)has become a crucial indicator for assessing both their social integration and the effectiveness of integration policies.However,few studies have systematically linked immigration law and policy to SWB through a structured framework of human needs.This study aims to assess how European Union(EU)immigration policies influence immigrants’SWB by facilitating the fulfillment of hierarchical needs based on Maslow’s theory.Methods:Using data from the European Social Survey(ESS,2010–2023),this study analyzed 28,854 first-generation and second-generation immigrants across 24 EU member states.This study employed hierarchical regression models to assess the relative contribution of five levels of needs-physiological,safety,social,esteem,and self-actualization-in predicting life satisfaction and happiness,controlling for sociodemographic factors.Results:Safety needs-comprising perceived safety and institutional trust-produced the largest model improvement(ΔR^(2)≈0.06–0.07).Physiological needs(stable income and self-rated health)also had significant positive effect(β=0.06–0.25,p<0.001).Social and esteem needs showed moderate associations(β≈0.09–0.17,p<0.001),while self-actualization needs(education and union membership)displayed generational variation(β=0.02–0.10,p<0.01).Conclusion:This study not only validates the applicability of Maslow’s theory in migration research but also empirically establishes a policy hierarchy:ensuring physiological and safety needs as a foundation,supporting social and esteem needs,and enabling self-actualization pathways are essential for enhancing immigrant well-being.The findings offer valuable theoretical insights and practical guidance for refining immigrant integration policies within the EU’s multi-level governance structure.
文摘The city of São Paulo in Brazil has many Japanese restaurants.Meanwhile,in Hamamatsu,Japan,there are also many places to eat Brazilian food.Why is each country’s food so popular in the other?The answer goes back to the early 20th century.
基金Hebei Province Higher Education Teaching Reform Research and Practice Program(Project No.:2022GJJG467)。
文摘With blended learning emerging as a mainstream paradigm in higher education,the Document Security Technology course faces persistent challenges,including vague instructional objectives and low learning efficiency.Simultaneously,the profession demands stronger self-directed learning capabilities from practitioners.To address these issues,this study develops a“Five-in-One”self-directed learning model comprising five interrelated dimensions:goal orientation,instructional regulation,cognitive development,technological resources,and process monitoring.The application of this model has significantly improved course evaluation outcomes,enhanced faculty teaching and research capacity,strengthened students’practical and innovative skills,and expanded the course’s reach and social impact.The model thus provides both a theoretical framework and a practical pathway for the reform of similar applied courses.
文摘After Donald Trump returned to the White House,the U.S.government launched a host of measures of“tariff wars”.In addition to announcing tariffs on goods imported to the United States from Canada,Mexico and China,the government also imposed trade restrictions on specific industries including steel,aluminum and copper,as well as advanced plan for“reciprocal tariffs”.Donald Trump claimed that a“tariff war”would correct trade imbalances,boost government revenue and promote the reshoring of manufacturing to the United States.By leveraging tariffs,the U.S.also attempts to achieve goals in border security,illegal immigration and fentanyl control.Undoubtedly at a central position in Trump’s second term in office,the“tariff war”will exert impacts far beyond economic and trade policies and upon the direction of China-U.S.relations.
文摘Hu Junhui,president of Tianfu Association(Singapore)and recipient of the Public Service Medal(PBM),has been leading community efforts to help new Chinese immigrants integrate into Singaporean society.Originally from Hebei Province in China,Hu arrived in Singapore in 1994 as one of the first technical professionals dispatched by China.Since then,he has built a life and career firmly rooted in Singapore.Over more than four years at China Construction(South Pacific)Development Co Pte Ltd,he rose through the ranks from project engineer to site manager and eventually project director.In 1999,he left the company to start his own business,setting up a construction firm with several partners.His focus shifted to real estate in 2007,when he co-founded JVA Venture Pte Ltd.
文摘Against the backdrop of the 35th anniversary of China-Singapore diplomatic relations,Tianfu Association(Singapore)has emerged as a key force fostering closer people-to-people and economic ties between the two countries.Founded in January 2000 by a group of new immigrants from China’s Sichuan Province,the association was the first Chinese immigrant organization established after diplomatic ties were formed between Singapore and China.Over the past two decades,it has actively engaged in local affairs and now serves as a council member of the Singapore Federation of Chinese Clan Associations.Today,it is widely recognized as one of the most vibrant and influential new immigrant groups promoting integration into Singaporean society.
基金supported by the National Key R&D Program of China(2020YFA0712901).
文摘We study age-structured branching models with reproduction law depending on the remaining lifetime of the parent. The lifespan of an individual is determined at its birth and its remaining lifetime decreases at the unit speed. The models, without or with immigration, are constructed as measure-valued processes by pathwise unique solutions of stochastic equations driven by time-space Poisson random measures. In the subcritical branching case, we give a sufficient condition for the ergodicity of the process with immigration. Two large number laws and a central limit theorem of the occupation times are proved.
基金Supported by the Fundamental Research Funds for the Central Universities(GK261002145)Key Teaching Reform Research of Shaanxi Normal University in 2014(14JG07)Teacher Education Program of Shaanxi Normal University in 2014(JSJY2014J014)~~
文摘Based on field survey and research of Hanzhong, relocation of Nanzheng County was explored and the existing problems were analyzed. Furthermore, the re- gional characters of Nanzheng County were investigated to analyze the feasibility and necessity of relocation with lots of data and evaluation was made on relocation of Nanzheng County. In addition, the existing problems of relocation were concluded and the prospect of the county was discussed, which is of significance for relocation in Nanzheng County and even southern Shaanxi Province.
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In 1971 the government of Canada adopted the policy of multiculturalism. Since then Canada has become the first western country to announce and implement an official policy of multiculturalism. While it is not easy to achieve this policy. The policies seem just to strengthen the racial consciousness in some extent, and the immigrant groups have to tackle the problem of how to fuse into the Canadian culture. Multiculturalism will have a bright future only if it would experience constant adjustment and improvement.
基金This work was supported by UK EPSRC(No.EP/E060722/01)Broil FAPESP(Proc.04/04289-6).
文摘Dynamic optimization problems are a kind of optimization problems that involve changes over time. They pose a serious challenge to traditional optimization methods as well as conventional genetic algorithms since the goal is no longer to search for the optimal solution（s） of a fixed problem but to track the moving optimum over time. Dynamic optimization problems have attracted a growing interest from the genetic algorithm community in recent years. Several approaches have been developed to enhance the performance of genetic algorithms in dynamic environments. One approach is to maintain the diversity of the population via random immigrants. This paper proposes a hybrid immigrants scheme that combines the concepts of elitism, dualism and random immigrants for genetic algorithms to address dynamic optimization problems. In this hybrid scheme, the best individual, i.e., the elite, from the previous generation and its dual individual are retrieved as the bases to create immigrants via traditional mutation scheme. These elitism-based and dualism-based immigrants together with some random immigrants are substituted into the current population, replacing the worst individuals in the population. These three kinds of immigrants aim to address environmental changes of slight, medium and significant degrees respectively and hence efficiently adapt genetic algorithms to dynamic environments that are subject to different severities of changes. Based on a series of systematically constructed dynamic test problems, experiments are carried out to investigate the performance of genetic algorithms with the hybrid immigrants scheme and traditional random immigrants scheme. Experimental results validate the efficiency of the proposed hybrid immigrants scheme for improving the performance of genetic algorithms in dynamic environments.
基金supported by the National Natural Science Foundation for Young Scholars of China(No.51208414)the Education Department of Shaanxi Province Special Scientific Research(No.12JK0650)
文摘Two sequencing batch reactors（SBRs） were operated for 100 days under aerobic conditions,with one being fed with unsterilized municipal wastewater（USBR）, and the other fed with sterilized municipal wastewater（SSBR）. Respirometric assays and fluorescence in situ hybridization（FISH） results show that active nitrifiers were present in the unsterilized influent municipal wastewater. The maximum ammonia utilization rate（AUR） and nitrite utilization rate（NUR） of the unsterilized influent were 0.32 ± 0.12 mg NH4＋-N/（L·hr） and0.71 ± 0.18 mg NO2--N/（L·hr）. Based on the maximum utilization rates, the estimated seeding intensity for the ammonia oxidizing bacteria（AOB） and nitrite oxidizing bacteria（NOB） of the USBR was 0.08 g AOB/（g AOB·day） and 0.20 g NOB/（g NOB·day） respectively. The fraction of nitrifiers/total bacteria in the influent was 5.35% ± 2.1%, the dominant AOB was Nitrosomonas spp., Nitrosococcus mobilis hybridizated with Nsm156, and the dominant NOB was Nitrospira hybridizated with Ntspa662. The influent nitrifiers potentially seeded the activated sludge of the bioreactor and hence demonstrated a mitigation of the acclimatization times and instability during start-up and early operation. The AUR and NUR in the USBR was 15% and 13% higher than the SSBR respectively during the stable stage, FISH results showed that nitrifiers population especially the Nitrospira in the USBR was higher than that in the SSBR. These results indicate that the natural continuous immigration of nitrifiers from municipal influent streams may have some repercussions on the modeling and design of bioreactors.
基金supported by the National Key R&D Program of China(No.2016YFC0502204)the National Natural Science Foundation of China(Nos.41672331,U1906223,41807316)。
文摘Organic and inorganic materials migrate downstream and have important roles in regulating environmental health in the river networks.However,it remains unclear whether and how a mixture of materials(i.e.,microbial species)from various upstream habitats contribute to microbial community coalescence upstream of a dam.Here we track the spatial variation in microbial abundance and diversity in the Three Gorges Reservoir based on quantitative PCR and 16 S rRNA gene high-throughput sequencing data.We further quantitatively assess the relative contributions of microbial species from mainstem,its tributaries,and the surrounding riverbank soils to the area immediately upstream of the Three Gorges Dam(TGD).We found an increase of microbial diversity and the convergent microbial distribution pattern in areas immediately upstream of TGD,suggesting this area become a new confluence for microbial diversity immigrating from upstream.Indeed,the number of shared species increased from upstream to TGD but unique species decreased,indicating immigration of various sources of microbial species overwhelms local environmental conditions in structuring microbial community close to TGD.By quantifying the sources of microbial species close to TGD,we found little contribution from soils as compared to tributaries,especially for sites closer to TGD,suggesting tributary microbes have greater influence on microbial diversity and environmental health in the Three Gorges Reservoir.Collectively,our results suggest that tracking microbial geographic origin and evaluating accumulating effects of microbial diversity shed light on the ecological processes in microbial communities and provide information for regulating aquatic ecological health.
文摘Hepatitis B virus(HBV) is the most common cause of hepatitis worldwide, with nearly 350 million people chronically infected and 600000 deaths per year due to acute liver failure occurring during acute hepatitis or, more frequently, in HBV-related liver cirrhosis or hepatocellular carcinoma. Ongoing immigration from countries with a high HBV endemicity to those with a low HBV endemicity warrants particular attention to prevent the spread of HBV infection to the native population. This review article analyzes the epidemiology and virological and clinical characteristics of HBV infection in immigrant populations and in their host countries, and suggests prophylactic measures to prevent the spread of this infection. Among the immigrants from different geographical areas, those from South East Asia and sub-Saharan Africa show the highest prevalences of hepatitis B surface antigen(HBs Ag) carriers, in accordance with the high endemicity of the countries of origin. The molecular characteristics of HBV infection in immigrants reflect those of the geographical areas of origin: HBV genotype A and D predominate in immigrants from Eastern Europe, B and C in those from Asia and genotype E in those from Africa. The literature data on the clinical course and treatment of HBs Agpositive immigrants are scanty. The management of HBV infection in immigrant populations is difficult and requires expert personnel and dedicated structures for their assistance. The social services, voluntary operators and cultural mediators are essential to achieve optimized psychological and clinical intervention.
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 National Key Research and Development Project(2019YFA802703)National Natural Science Foundation of China Grants(331822033,31771623,32000568)+1 种基金Fundamental Research Funds for the Central Universities Grant(XDJK2020C041)Natural Science Foundation of Chongqing(CSTC2020JCYJMSXMX0104)。
文摘T cells play a critical role in immunity to protect against pathogens and malignant cells.T cell immunodeficiency is detrimental,especially when T cell perturbation occurs during severe infection,irradiation,chemotherapy,and age-related thymic atrophy.Therefore,strategies that enhance T cell reconstitution provide considerable benefit and warrant intensive investigation.Here,we report the construction of a T cell ablation model in Tg(coro1a:Den NTR)zebrafish via metronidazole administration.The nascent T cells are mainly derived from the hematopoietic cells migrated from the kidney,the functional homolog of bone marrow and the complete recovery time is 6.5 days post-treatment.The cxcr4b gene is upregulated in the responsive hematopoietic cells.Functional interference of CXCR4 via both genetic and chemical manipulations does not greatly affect T lymphopoiesis,but delays T cell regeneration by disrupting hematopoietic migration.In contrast,cxcr4b accelerates the replenishment of hematopoietic cells in the thymus.Consistently,Cxcl12b,a ligand of Cxcr4,is increased in the thymic epithelial cells of the injured animals.Decreased or increased expression of Cxcl12b results in compromised or accelerated T cell recovery,respectively,similar to those observed with Cxcr4b.Taken together,our study reveals a role of CXCR4-CXCL12 signaling in promoting T cell recovery and provides a promising target for the treatment of immunodeficiency due to T cell injury.
