Simulation of Spread of Infectious Diseases and Population Mobility in a Deterministic Epidemic Patch Model

Computer simulation models are widely applied in various areas of the health care sector, including the spread of infectious diseases. Patch models involve explicit movements of people between distinct locations. The aim of the present work has been designed and explored a patch model with population mobility between different patches and between each patch and an external population. The authors considered a SIR （susceptible-infected-recovered） scheme. The model was explored by computer simulations. The results show how endemic levels are reached in all patches of the system. Furthermore, the performed explorations suggest that the people mobility between patches, the immigration from outside the system and the infection rate in each patch, are factors that may influence the dynamics of epidemics and should be considered in health policy planning.

On Population Mobility in Market Economy

Regular and extensive social population mobility in natural economy is neither necessary nor possible while in a planned economic system, social population distribution is necessary but social population mobility is unlikely. Modern market economy as a highly mobile economy has a free-mobile population characteristic of market economy, which is fundamental to optimize human resource distribution. The rule for the modern market-based population movement is as follows: If the mobile population is the rational behavior choosers, under the permissive developmental environment as arranged by the social system, they tend to move from low profit-making fields to high income fields when there exists comparable difference of income in different regions and different industries, and various potential and practical profit-making chances. The degree of difference in comparable income is positively co-relative to the velocity and flux of mobile population.

Population mobility change for controlling the transmission of COVID-19:mobile phone data analysis in nine cities of China

Mobility restriction measures were the main tools to control the spread of COVID-19,but the extent to which the mobility has decreased remained unsure.We investigated the change in local population mobility and its correlation with COVID-19 infections,using 1185 billion aggregated mobile phone data records in nine main cities in China from 10 January to 24 February 2020.The mobility fell by as much as 79.57%compared to the normal days in 2020 and by 58.13%compared to the same lunar period in 2019.The daily incidence of COVID-19 was significantly correlated with local daily mobility(R2=0.77,P<0.001).The instantaneous reproduction number R(t)declined by 3%when mobility was reduced by 10%in the GLM analysis(P<0.05).Our study indicated that the decreased mobility level,driven by a mixture effect of holiday and public health interventions,could substantially reduce the transmission of COVID-19 to a low level.Our study could provide evidence of mobility restriction to control local transmission for other places facing COVID-19 outbreaks or potential next waves.

An Analysis on the Improvement of the Housing Security System Based on Population Mobility

China's urban housing security system has developed for years. The dual division between registered population and migrant population in cities still exists. While local governments undertake responsibility of the housing security through intergovernmental duty division, it is not appropriate because housing security is a kind of national income redistribution that belongs to the central government. From the perspective of the population mobility, the article discusses the problems of the current housing security system, based on which it proposes three recommendations for improving the existing housing security system. First, we should make a distinction between the national income redistribution carried out by the central government and the public services provided by local governments. The responsibility and fi scal expenditure of the local, provincial, and central government should be clearly defined. Second, intergovernmental fiscal transfer payment should be designed according to the population mobility status. Third, the housing security system should protect the demands of the new generation of peasant workers and migrant families.

Malaria elimination in Lao PDR:the challenges associated with population mobility

Although the Lao People’s Democratic Republic(Lao PDR)is comparatively small landlocked country with patterns of both in-and out-migration,its human migration situation has been poorly studied.This is despite all of the country’s 18 provinces sharing both official and unofficial border checkpoints with neighboring countries.Economic reforms in the last decade have seen a gradual increase in the promotion of foreign investment,and main towns and transportation networks have been expanding thus offering new opportunities for livelihoods and economic activities.In the last decade,there has also been a significant reduction of reported malaria cases in Lao PDR and while this is an important prerequisite for eliminating malaria in the country,malaria outbreaks reported in the last four years suggest that population mobility,particularly in the south,is an important factor challenging current control efforts.Bolder investment in social sector spending should be geared towards improving health service provision and utilization,ensuring equitable access to primary health care(including malaria)through efforts to achieve universal health coverage targets.This should be extended to populations that are mobile and migrants.The local government plays a critical role in supporting policy and enforcement issues related to private sector project development in the provinces.Cross-border initiatives with neighboring countries,especially in terms of data sharing,surveillance,and response,is essential.Mechanisms to engage the private sector,especially the informal private sector,needs to be explored within the context of existing regulations and laws.Existing and new interventions for outdoor transmission of malaria,especially in forest settings,for high-risk groups including short-and long-term forest workers and their families,mobile and migrant populations,as well as the military must be combined into integrated packages with innovative delivery mechanisms through social marketing approaches.This should happen at multiple points in the mobility pathway and involve the private sector rather than being fully reliant on the national malaria vertical program This article based on the review of existing literature from abstracts and full texts,includes published,peer-reviewed English language literature sourced through PubMed and grey literature sources through Google and Google Scholar.The review included also case reports,sector reports,conference proceedings,research reports,epidemiology studies,qualitative studies,and census reports in both Lao and English languages.The authors used the search terms:malaria and mobile populations,malaria control program and elimination,health system performance,malaria outbreak,Lao PDR;and included articles published until June 2015.

Study on Influencing Factors of Mental Health of Mobile Young White-Collar Workers in China

Mobile young white-collar workers not only have the characteristics of mobile young people,but also have the characteristics of general white-collar workers.Under the influence of both,their mental health may be suffering from“double disadvantage”.So,based on an ecological model of the stress process,this paper tries to use the data of the questionnaire on the mental health of mobile young white-collar workers in Zhejiang Province to explore the influence of some factors in the middle workplace and residence place on the mental health of micro individuals.The results show that:(1)The working environment with high control and low freedom and the workplace discrimination against the mobile status will have a negative impact on the mental health of mobile young white-collar workers;(2)Financial anxiety in daily life will lead to a decline in the mental health level of mobile young white-collar workers;(3)Good organizational support and neighborhood social relations can significantly relieve life pressure,so as to effectively improve the mental health of mobile young white-collar workers.It can be seen that we also need to pay more attention to the mental health of mobile young white-collar workers in order to improve their situation.

Assessing the Effect of Global Travel and Contact Restrictions on Mitigating the COVID-19 Pandemic

Travel restrictions and physical distancing have been implemented across the world to mitigate the coronavirus disease 2019(COVID-19)pandemic,but studies are needed to understand their effectiveness across regions and time.Based on the population mobility metrics derived from mobile phone geolocation data across 135 countries or territories during the first wave of the pandemic in 2020,we built a metapopulation epidemiological model to measure the effect of travel and contact restrictions on containing COVID-19 outbreaks across regions.We found that if these interventions had not been deployed,the cumulative number of cases could have shown a 97-fold(interquartile range 79–116)increase,as of May 31,2020.However,their effectiveness depended upon the timing,duration,and intensity of the interventions,with variations in case severity seen across populations,regions,and seasons.Additionally,before effective vaccines are widely available and herd immunity is achieved,our results emphasize that a certain degree of physical distancing at the relaxation of the intervention stage will likely be needed to avoid rapid resurgences and subsequent lockdowns.

Can Talent Policies Attract Population Inflows?—An Empirical Analysis Based on Spatial Panel Modeling

To analyze the spatial influence mechanism of talent policy on population flow, this study compares the government work reports of 31 provinces between 2008 and 2020, and quantifies regional talent policies in nine aspects, including talent evaluation and incentives, utilizing a comprehensive, standardized, and continuous approach. Additionally, this paper develops a spatial econometric analysis model and expands on the conventional neighborhood, distance, and economic matrices by constructing a spatial weight matrix that reflects talent flow. The findings indicate that population movement exhibits spatial clustering patterns. The regional government's talent policy, primarily based on talent evaluation and incentives, positively influences population inflow. Moreover, during the implementation of talent policies, local governments demonstrate cooperative relationships. The inter-regional spillover effect between talent evaluation and talent incentives is significantly positive. In other words, a stronger local talent evaluation policy, along with robust talent incentives, encourages population inflow from neighboring provinces. However, this conclusion may vary in different regions and over time. Recently, the spatial spillover effect of population inflow and the impact of talent policies have not shown significant results. Additionally, the attractiveness of talent evaluation in the eastern region surpasses that of talent incentives, while the opposite holds true for the central and western regions. This study investigates the impact of local government talent policies on population inflow and its spatial spillover effect, offering theoretical support for intergovernmental cooperation.

The spatiotemporal analysis of the population migration network in China,

Population migration is a critical component of large-scale spatiotemporal models of infectious disease transmission.Identifying the most influential spreaders in networks is vital to controlling and understanding the spreading process of infectious diseases.We used Baidu Migration data for the whole year of 2021 to build mobility networks.The nodes of the network represent cities,and the edges represent the population flow between cities.By applying the k-shell decomposition and the Louvain algorithm,we could get the k-shell values for each city and community partition.Then,we identified the most efficient nodes or pathways in a complex network by generating random networks.Furthermore,we analyzed the eigenvalue of the migration matrix to find the nodes that have the most impact on the network.We also found the consistency between k-shell value and eigenvalue through Kendall's t test.The main result is that in Spring Festival and National Day,the network is at higher risk of an infectious disease outbreak and the Yangtze River Delta is at the highest risk of an epidemic all year around.Shanghai is the most significant node in both k-shell value and eigenvalue analysis.The spatiotemporal property of the network should be taken into account to model the transmission of infectious diseases more accurately.

模拟城际人口流动的量子谐振子模型

The simulation of intercity population mobility helps to deepen the understanding of intercity population mobility and its underlying laws,which has great importance for epidemic prevention and control,social management,and even urban planning.There are many factors that affect intercity population mobility,such as socioeconomic attributes,geographical distance,and industrial structure.The complexity of the coupling among these factors makes it difficult to simulate intercity population mobility.To address this issue,we propose a novel method named the quantum harmonic oscillator model for simulation of intercity population mobility(QHO-IPM).QHO-IPM describes the intercity population mobility as being affected by coupled driving factors that work as a multioscillator-coupled quantum harmonic oscillator system,which is further transformed by the oscillation process of an oscillator,namely,the breaking point of intercity population mobility.The intercity population mobility among seven cities in the Beijing-Tianjin-Hebei region and its surrounding region is taken as an example for verifying the QHO-IPM.The experimental results show that(1)compared with the reference methods(the autoregressive integrated moving average(ARIMA)and long and short-term memory(LSTM)models),the QHO-IPM achieves better simulation performance regarding intercity population mobility in terms of both overall trend and mutation.(2)The simulation error in the QHO-IPM for different-level intercity population mobility is small and stable,which illustrates the weak sensitivity of the QHO-IPM to intercity population mobility under different structures.(3)The discussion regarding the influence degree of different driving factors reveals the significant“one dominant and multiple auxiliary”factor pattern of driving factors on intercity population mobility in the study area.The proposed method has the potential to provide valuable support for understanding intercity population mobility laws and related decision-making on intercity population mobility control.

The Influence of Significant Public Health Events on Offline Consumption and Its Pathways

In the face of a significant public health event,consumers may either increase their panic buying or decrease their willingness to make purchases.This study focuses on the impact of a significant public health event on offline store sales and consumer consumption,utilizing data from chain convenience stores in Hefei and Wuhu during early 2019 and early 2020 in China.Employing a difference-in-differences model,the study investigates the effect of the significant public health event outbreak on weekly store sales,order numbers,and consumer consumption in terms of product quantities,transaction amount,average amount per order,and transaction frequency.Different from prior literature that finds hoarding behavior of consumers online,the findings of this paper indicate a significant reduction in stores’offline weekly sales and order numbers,as well as consumers’offline weekly consumption across the four dimensions,as a result of the significant public health event outbreak.Additionally,employing a mediation model,the study explores the pathway of population mobility through which the significant public health event adversely affects offline consumption.Furthermore,subset analysis is conducted for stores located in different areas and consumers with varying characteristics,revealing that the aforementioned conclusions predominantly apply to stores situated in office areas and residential areas,as well as consumers with either no apparent preference for different product categories or a noticeable preference for food.

Population Migration and Brain Drain in Northeast China

Migration has been the mam driver during the last decade of population change in Northeast China,an area made up of three provinces,Heilongjiang,Jilin and Liaoning.A net out flow of population has resulted in the loss of younger laborers in the area.More than two million people migrate out of Northeast China,and the number is increasing.The flow direction is from north to south.Liaoning in the south is a province of net in-migration,and Jilin and Heilongjiang in the north are provinces of net out-migration.There are large differences in the education and age structure of inflow and outflow migrants;the out-flow areas are losing human capital.This study uses a Dynamic Monitoring Survey of Migrant Population to analyze population flows in Northeast China,and uses employment information for university graduates to analyze the problem of brain drain in this area.

Mobile population dynamics and malaria vulnerability:a modelling study in the China-Myanmar border region of Yunnan Province,China

Background:The China-Myanmar border region presents a great challenge in malaria elimination in China,and it is essential to understand the relationship between malaria vulnerability and population mobility in this region.Methods:A community-based,cross-sectional survey was performed in five villages of Yingjiang county during September 2016.Finger-prick blood samples were obtained to identify asymptomatic infections,and imported cases were identified in each village(between January 2013 and September 2016).A stochastic simulation model(SSM)was used to test the relationship between population mobility and malaria vulnerability,according to the mechanisms of malaria importation.Results:Thirty-two imported cases were identified in the five villages,with a 4-year average of 1 case/year(range:0-5 cases/year).No parasites were detected in the 353 blood samples from 2016.The median density of malaria vulnerability was 0.012(range:0.000-0.033).The average proportion of mobile members of the study population was 32.56%(range:28.38-71.95%).Most mobile individuals lived indoors at night with mosquito protection.The SSM model fit the investigated data(χ2=0.487,P=0.485).The average probability of infection in the members of the population that moved to Myanmar was 0.011(range:0.0048-0.1585).The values for simulated vulnerability increased with greater population mobility in each village.Conclusions:A high proportion of population mobility was associated with greater malaria vulnerability in the China-Myanmar border region.Mobile population-specific measures should be used to decrease the risk of malaria re-establishment in China.

Assessment of net lending strategy to better reach mobile and migrant populations in malaria endemic areas of Cambodia

Background:In Cambodia,internal migration involves migrants moving from non-malaria endemic areas to malaria endemic areas and vice versa.The majority of them work in farms or forests with various malaria transmission levels.In Cambodia,as one of the national approaches to ensure LLIN accessibility and use among mobile and migrant populations(MMPs),a lending scheme of long lasting insecticide treated nets(LLINs)was initiated among farm workers.Through this net lending program,LLINs and long-lasting insecticide treated hammock nets(LLIHNs)will be distributed annually at workplace(e.g.longstanding farms,plantations,industrial sites,as identified by operational district and health center staff)on a ratio of one LLIN per one worker.The main objective of this study is to assess MMPs’accessibility to LLINs through a lending scheme with plantation owners in remote malaria endemic areas of Cambodia.Methods:The study used a cross-sectional survey among MMPs using two-stage cluster sampling method.The sampling frame is the list of farms in the four provinces of Banteay Meanchey,Battambang,Pailin,and Pursat in western and northwestern Cambodia bordering with Thailand where the LLIN lending scheme was implemented and where an estimated 100000 MMPs worked annually.The assessment was carried out from January to February 2013 in these four provinces.It was estimated that 768 workers would be required.Results:A total of 702 MMPs were interviewed.The ratio of male:female is 1:1.The age group of 21-60 was the largest accounting for 77.6%.About 91%of the MMPs stayed on the farm for less than 6 months.93.2%of them owned either untreated or insecticide treated nets.LLINs and LLIHNs accounted for 89.5%;and 46.6%of them borrowed the nets from a lending scheme.Among those workers who have LLINs/LLIHNs,99%slept under LLINs/LLIHNs the night before.However,only 87.4%knew that sleeping under LLINs/LLIHNs protects against malaria.Conclusions:LLIN lending scheme provides an important delivery channel for a substantial percentage of net accessibility(46.6%)to the Cambodian national free-net distribution campaign in remote malaria endemic areas.

Assessment of malaria control consultation and service posts in Yunnan, P. R. China

Background:This paper seeks to assess the function of malaria control consultation and service posts(MCCSPs)that are located on the border areas of Yunnan province,P.R.China,as a strategy for eliminating malaria among the mobile and migrant population in these areas.Methods:A retrospective descriptive analytical study was conducted.Blood smear examinations conducted at all MCCSPs in Yunnan from 2008 to 2014 were analysed.A cross-sectional survey was conducted in 2014 to understand how the MCCSPs function and to elucidate the quality of the blood smear examinations that they conduct.Results:Out of the surveyed MCCSPs,66%(39/59),22%(13/59),and 12%(7/59)were attached to local township hospitals,village health clinics,and the county centre for disease control and prevention or private clinics,respectively.More than 64%(38/59)of the posts’staff were part-time workers from township hospitals and village health facilities.Less than 31%(18/59)of the posts’staff were full-time workers.A total of 35 positive malaria cases were reported from seven MCCSPs in 2014.Four MCCSPs were unable to perform their functions due to under staffing in 2014.There was a small fluctuation in blood smear examinations from January 2008 to June 2009,with two peaks during the period from July 2009 to October 2010.The number of blood smear examinations has been increasing since 2011.The yearly mean number of blood smear examinations in each post increased from 44 per month in 2011 to 109 per month in 2014,and the number of positive malaria cases detected by blood smear examinations has declined(χ^(2)=90.67,P=0.000).The percentage of people from Yingjiang county getting blood smear examinations increased between 2008 and 2014,while percentages of the mobile population including Myanmar people,people from other provinces,and people from other Yunnan counties getting blood smear examinations decreased.Conclusion:MCCSPs face challenges in the phase of malaria elimination in Yunnan,China.New case detection strategies should be designed for MCCSPs taking into account the current trends of migration.