Analysis and Prediction of Population Aging Trend Based on Population Development Model

Regional dimensions and trends in population aging: Russia/Eastern Europe Population aging is a global phenomenon and countries of Eastern European also experience rapid increase in the proportion of older people. The proportion of elderly people in the Eastern Europe is currently lower than in the European region as a whole. However this population aging is expected to continue over the next few decades, eventually leading to the convergence in the proportion of older people in the countries of Eastern and Western Europe. Aging of population is often measured through an increase in the percentage of elderly people of retirement ages. A society is considered to be relatively old when the fraction of the population aged 65+ years exceeds 8-10% (Kinsella and Velkoff 2001). According to this definition, the populations of the Eastern Europe and Russia are becoming very old, because the percentage of elderly people reached the levels of 14.2% and 13.8% correspondingly in 2005, and it is expected to increase further. The choice of the boundary for old age (65 years and over) is rather arbitrary therefore many demographers who study Eastern European countries also use 60 years cut-off (retirement age for many countries of the Eastern Europe). In this case a population is considered to be old, when the proportion aged 60+ years exceeds 10-12% (Kinsella and Velkoff 2001). Table 1 presents data on the proportion of population age sixty and over for selected countries. Note that populations of Bulgaria, Hungary and Ukraine were older than the population of the European region in 2005. In addition to these three

BackgroundOphiopogon japonicus, mainly planted in Sichuan (CMD) and Zhejiang (ZMD) province in China, has a lengthy cultivation history. During the long period of domestication, the genetic diversity of cultivated O. japonicus has substantially declined, which will affect the population continuity and evolutionary potential of this species. Therefore, it is necessary to clarify the phylogeography of cultivated O. japonicus to establish a theoretical basis for the utilization and conservation of the genetic resources of O. japonicus.ResultThe genetic diversity and population structure of 266 O. japonicus individual plants from 23 sampling sites were analyzed based on 4 chloroplast DNA sequences (atpB-rbcL, rpl16, psbA-trnH and rpl20-5’rps12) to identify the effects of domestication on genetic diversity of cultivars and determine their geographic origins. The results showed that cultivated O. japonicus and wild O. japonicus had 4 and 15 haplotypes respectively. The genetic diversity of two cultivars (Hd = 0.35700, π = 0.06667) was much lower than that of the wild populations (Hd = 0.76200, π = 0.20378), and the level of genetic diversity in CMD (Hd = 0.01900, π = 0.00125) was lower than that in ZMD (Hd = 0.06900, π = 0.01096). There was significant difference in genetic differentiation between the cultivated and the wild (FST = 0.82044), especially between the two cultivars (FST = 0.98254). This species showed a pronounced phylogeographical structure (NST > GST, P < 0.05). The phylogenetic tree showed that the genetic difference between CMD and ZMD was not enough to distinguish the cultivars between the two producing areas by using O. amblyphyllus Wang et Dai as an outgroup. In addition, both CMD and ZMD have a closer relationship with wild populations in Sichuan than that in Zhejiang. The results of the TCS network and species distribution model suggested that the wild population TQ located in Sichuan province could serve as the ancestor of cultivated O. japonicus, which was supported by RASP analysis.ConclusionThese results suggest that cultivated O. japonicus has experienced dramatic loss of genetic diversity under anthropogenic influence. The genetic differentiation between CMD and ZMD is likely to be influenced by founder effect and strong artificial selection for plant traits. It appears that wild populations in Sichuan area are involved in the origin of not only CMD but also ZMD. In addition, we also raise some suggestions for planning scientific strategies for resource conservation of O. japonicus based on its genetic diversity and population structure.

The article deals with the trends of population ageing in the Republic of Azerbaijan. The author considers the stages of change of population size and age structure in the 20th and the 21st centuries as a result of historical evolution of birth rate and death rate. Based on the analysis of fertility trends and life expectancy, it is shown that the decline in fertility has so far been the most important factor in the population ageing, whereas the decline in the mortality in older ages is only beginning to contribute to this process. It is emphasized that anomalies in the sex ratio at birth lead to accelerated ageing of the population. The gradual ageing and reduction of the share of the working-age population, as well as the growth of the dependency ratio and the exhaustion of the potential of the first demographic dividend, are also analysed in the paper.

Objectives: In 2006, Iran’s fertility rate fell below the replacement level and, after a slight increase in the early 2010s, it has continued to decline thereafter. Replacement-level fertility means that each woman, on average, has only about two children, which is equivalent to zero population growth. Despite this, population growth has remained positive throughout these years. Positive population growth under conditions of replacement-level fertility is a phenomenon called "population momentum." This study aims to examine the impact of population momentum on the aging trend of Iran's population and its implications for social policy. Since population momentum, which results from past changes in fertility and mortality rates, affects particularly elderly age groups, it plays a significant role in accelerating population aging. Materials and methods: This study uses census data, fertility and mortality estimates from 1996 to 2016, and a 100-year population projection for Iran using a cohort-component method by R software. The study calculates population momentum and analyzes population aging trends through age decomposition. Findings: The results show that the positive values of population momentum are gradually declining. Age decomposition of momentum reveals that the highest values of momentum are allocated to the elderly population. According to the population projection, the elderly population of Iran, particularly influenced by population momentum, will increase fourfold, and the aging index will rise from about 25 in 2016 to 110 in 2061. However, this increasing trend of elderly population will not continue beyond 2061, as momentum growth becoming zero and then negative due to low fertility rates. Conclusion: The results show that population momentum plays a key role in accelerating the aging of the Iran’s population. Despite the high rate of population aging in Iran, we face major challenges in the field of social policies for aging. This situation requires policymakers to adopt necessary reforms in retirement, health, elderly care, and family friendly policies.

Objective To investigate the levels of antibody to measles, rubella and mumps viruses in healthy population in Sichuan province, 2018. Methods Totally 1 901 healthy people were selected from 7 age groups in 9 counties of Sichuan province. Serum samples of them were collected to test the IgG antibody to measles, rubella and mumps viruses by enzyme-linked immunosorbent assay (ELISA), and analyzed statistically. Results In 1 901 subjects, the positivity rates of measles, rubella and mumps IgG antibody were 83.69%, 71.59%, 63.12% respectively, and the geometric mean titer (GMCs) were 1 289.92 mIU/ml, 87.63 IU/ml, and 425.62 U/ml respectively. There were significant differences in positivity rates of measles, rubella and mumps antibody among age groups and counties. There were no significant differences in GMCs of measles antibody among age groups and among counties, and the samples with full protection of measles (GMC≥1 000 mIU/ml) accounted for only 34.19%. There were significant differences in GMCs of rubella and mumps antibody among age groups and among counties. Conclusions The levels of antibody to measles, rubella and mumps were lower in healthy population in Sichuan. Vaccination should be strengthened in vulnerable areas and age groups. Key words: Measles; Rubella; Mumps; Antibody levels

The Procambarus clarkii production sector in Sichuan Province, China, is experiencing rapid growth. However, the industry faces significant challenges, including on-farm breeding and the widespread “Catch Big, Keep Small” farming practice, which have led to substantial genetic degradation within P. clarkii populations. Moreover, the uncertainty surrounding the origins of breeding stocks poses an additional obstacle to the local selection and cultivation of high-quality juvenile P. clarkii. With the objective of inferring the genetic lineage of cultivated P. clarkii in Sichuan, twelve microsatellite loci were employed to investigate the genetic characters of six P. clarkii populations from Sichuan and two from Hubei Province, China. The results revealed that the Sichuan populations exhibited higher levels of heterozygosity (Ho = 0.549~0.699, He = 0.547~0.607) and genetic diversity than the Hubei populations (Na = 4.00~5.250, PIC = 0.467~0.535). Notably, the DY population located in northeastern Sichuan showed the highest heterozygosity (Ho = 0.699, He = 0.607) and genetic diversity (Na = 5.250, PIC = 0.535) among the eight populations. Population structure, principal coordinate analysis and clustering analysis illuminated a close genetic relationship between the Qionglai population in Sichuan and the Jianli population in Hubei. Additionally, the remaining five Sichuan populations (Luxian, Nanxi, Xingwen, Neijiang and Daying) exhibited strong genetic affinity with the QianJiang population in Hubei, and particularly high genetic exchange may have occurred between Daying and Qianjiang (Fst = 0.001, Nm = 217.141). These results suggest that the primary cultivated P. clarkii populations in Sichuan likely originated from Qianjiang and Jianli counties in Hubei, with Qianjiang contributing a more substantial proportion. The genetic diversity of Sichuan populations was higher than those of some other Chinese P. clarkii farming provinces and even some native populations. Specifically, the Daying population emerges as a potential breeding germplasm source for crayfish in Sichuan. In contrast, the Qionglai population exhibits relatively low genetic diversity, highlighting the need for strategic enhancement through interactions with other populations to promote diversity and resilience. Furthermore, fostering genetic exchange among locally cultivated populations within the southern Sichuan basin is strategic to elevate the quality of P. clarkii germplasm resources.

SummaryBackgroundGiven the projected trends in population ageing and population growth, the number of people with dementia is expected to increase. In addition, strong evidence has emerged supporting the importance of potentially modifiable risk factors for dementia. Characterising the distribution and magnitude of anticipated growth is crucial for public health planning and resource prioritisation. This study aimed to improve on previous forecasts of dementia prevalence by producing country-level estimates and incorporating information on selected risk factors.MethodsWe forecasted the prevalence of dementia attributable to the three dementia risk factors included in the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 (high body-mass index, high fasting plasma glucose, and smoking) from 2019 to 2050, using relative risks and forecasted risk factor prevalence to predict GBD risk-attributable prevalence in 2050 globally and by world region and country. Using linear regression models with education included as an additional predictor, we then forecasted the prevalence of dementia not attributable to GBD risks. To assess the relative contribution of future trends in GBD risk factors, education, population growth, and population ageing, we did a decomposition analysis.FindingsWe estimated that the number of people with dementia would increase from 57·4 (95% uncertainty interval 50·4–65·1) million cases globally in 2019 to 152·8 (130·8–175·9) million cases in 2050. Despite large increases in the projected number of people living with dementia, age-standardised both-sex prevalence remained stable between 2019 and 2050 (global percentage change of 0·1% [–7·5 to 10·8]). We estimated that there were more women with dementia than men with dementia globally in 2019 (female-to-male ratio of 1·69 [1·64–1·73]), and we expect this pattern to continue to 2050 (female-to-male ratio of 1·67 [1·52–1·85]). There was geographical heterogeneity in the projected increases across countries and regions, with the smallest percentage changes in the number of projected dementia cases in high-income Asia Pacific (53% [41–67]) and western Europe (74% [58–90]), and the largest in north Africa and the Middle East (367% [329–403]) and eastern sub-Saharan Africa (357% [323–395]). Projected increases in cases could largely be attributed to population growth and population ageing, although their relative importance varied by world region, with population growth contributing most to the increases in sub-Saharan Africa and population ageing contributing most to the increases in east Asia.InterpretationGrowth in the number of individuals living with dementia underscores the need for public health planning efforts and policy to address the needs of this group. Country-level estimates can be used to inform national planning efforts and decisions. Multifaceted approaches, including scaling up interventions to address modifiable risk factors and investing in research on biological mechanisms, will be key in addressing the expected increases in the number of individuals affected by dementia.FundingBill & Melinda Gates Foundation and Gates Ventures.

China's economy is still developing rapidly, but the speed of growth has dropped noticeably; food production has broken historic records, and the trend towards price increases has been brought under control and is clearly dissipating; urban and rural living standard have continued to increase, but the rate of increase in income has slowed down; the employment environment has become harsher, and there have been noticeable problems with migrant workers returning to their villages, as well as with finding employment for new graduates. China has made a major effort to avert this critical situation and expanded its investments in order to guarantee stable, rapid economic and social development. The country is also working to break up the dualistic urban and rural structures in education, medical services, social security, and community services, and so on, and 2008 may thus also mark the year when China's social development entered a new historical stage. Keywords: China's economy; China's social development; employment; investments

In recent years, the number and proportion of the elderly population in China has been rising, and it is facing a serious trend of population aging. This paper focuses on the negative impact of Chinas relevant policies on population aging and birth rate. Through literature analysis and data survey, this paper finds that the implementation of Chinas family planning policy has to some extent suppressed the growth of the population, but also exacerbated issues such as population aging, labor shortage, and caused a decline in the fertility rate. To address this issue, the government needs to take more active and effective measures, including the increasing social security investment, encouraging fertility, and strengthening elderly welfare, to ensure the quality of life of the elderly population and sustainable economic development.

With the development of China's economy and the continuous transformation of society, the scale of the population flow in Sichuan Province continues to expand. It can be said that this huge group of floating population has become an important factor influencing Sichuan's economic development and social stability. The continuous inflow of rural population into the cities has played a very good role in promoting the urban economy, the speed of urban development and the process of urbanization. The instability of the floating population also brings certain hidden troubles for urban development. Based on spatial statistics, we use Lorenz curve, population distribution center of gravity, and spatial autocorrelation analysis methods to explore the characteristics of the spatial evolution of the population. Studying the spatial structure in Sichuan Province is of great significance to the promotion of Sichuan's economic development and reasonable development of human resources. 基于

As one of the important natural resources, oil resources play an irreplaceable role in China's social and economic development. At present, the social demand for oil is increasing gradually, and China's oil production is in the forefront of the world, which is both an opportunity and a challenge for the development of the oil industry. The research on petroleum geological exploration and storage in China is relatively lacking. As a non-renewable resource, excessive exploitation of oil will lead to the shortage of natural resources in China, which is not only extremely unfavorable to the development of the oil industry, but also leads to the collapse of China's social economy. Therefore, the relevant staff must do a good job in the corresponding reservoir work, conduct in-depth research on the exploration technology, and fully implement the reservoir evaluation scheme system, so as to improve the overall comprehensive level of China's petroleum geological exploration, carry out protective development on the utilization of petroleum resources on the basis of meeting the needs of China's social development, and improve the utilization rate of petroleum resources.

BackgroundMany endangered species exist in small, genetically depauperate, or inbred populations, hence promoting genetic differentiation and reducing long-term population viability. Forest Musk Deer (Moschus berezovskii) has been subject to illegal hunting for hundreds of years due to the medical and commercial values of musk, resulting in a significant decline in population size. However, it is still unclear to what extent the genetic exchange and inbreeding levels are between geographically isolated populations. By using whole-genome data, we reconstructed the demographic history, evaluated genetic diversity, and characterized the population genetic structure of Forest Musk Deer from one wild population in Sichuan Province and two captive populations from two ex-situ centers in Shaanxi Province.ResultsSNP calling by GATK resulted in a total of 44,008,662 SNPs. Principal component analysis (PCA), phylogenetic tree (NJ tree), ancestral component analysis (ADMIXTURE) and the ABBA-BABA test separated Sichuan and Shaanxi Forest Musk Deer as two genetic clusters, but no obvious genetic differentiation was observed between the two captive populations. The average pairwise FST value between the populations in Sichuan and Shaanxi ranged from 0.05–0.07, suggesting a low to moderate genetic differentiation. The mean heterozygous SNPs rate was 0.14% (0.11%—0.15%) for Forest Musk Deer at the genomic scale, and varied significantly among three populations (Chi-square = 1.22, p < 0.05, Kruskal–Wallis Test), with the Sichuan population having the lowest (0.11%). The nucleotide diversity of three populations varied significantly (p < 0.05, Kruskal–Wallis Test), with the Sichuan population having the lowest genetic θπ (1.69 × 10–3).ConclusionsGenetic diversity of Forest Musk Deer was moderate at the genomic scale compared with other endangered species. Genetic differentiation between populations in Sichuan and Shaanxi may not only result from historical biogeographical factors but also be associated with contemporary human disturbances. Our findings provide scientific aid for the conservation and management of Forest Musk Deer. They can extend the proposed measures at the genomic level to apply to other musk deer species worldwide.

Population aging has become a frequent occurrence due to changes in the global population structure, and it has a significant impact on the economic growth of many nations. Particularly in China, with the decline in fertility rates and the extension of life expectancy, the aging problem is further intensifying. The phenomenon of "fewer children and an aging population" is gradually becoming the norm, posing severe challenges to China's economic development. By searching for the relevant population data of the National Bureau of Statistics, this paper analyzes the current situation of Chinese population structure, analyzes the causes of population aging from four aspectsfertility policy, economic and social development, culture and education, and population migration. It also puts forward the impacts of population aging on economic growth, including the decrease in labor supply, the decline in consumption level and the increase in social pension pressure. This paper argues that even though the aging population structure has had a certain impact on China's social economy, people can turn challenges into opportunities. Furthermore, this paper proposes the coping strategies for China's population aging and promoting high-quality economic development, such as improving the elderly consumer market, giving full play to the leading role of government planning, improving the quality of the labor force, and forming an age-appropriate society. The purpose of this paper is to provide theoretical reference and practical guidance for China to cope with the challenges of population aging and the healthy development of population and economy.

Canada is a country with an aging population, especially in cities with small populations, such as Winnipeg and Yukon. The aging population trend is a double-edged sword, as it has both benefits and drawbacks. The downside is that it leads to a number of economic problems, including a reduced workforce and increased health care costs, while the upside is that it can boost demand for specific services, such as nursing homes and hospitals. Specifically, the paper aims to examine the factors that contribute to Canada's aging population trend and its effect on the workforce in these cities, including the retirement of baby boomers and declining birth rates. Also, it investigated the economic implications of an aging population, such as reduced labor supply and increased healthcare and insurance costs. Additionally, assessing the impact of population aging on these urban emerging industries and identifying potential policy solutions to mitigate the negative economic impact of population aging are presented in detail to provide readers with a clear framework. It can be inferred that the aging population trend in Canada is a complex issue that has both benefits and drawbacks. While it may boost demand for specific services, such as nursing homes and hospitals, it can also lead to a decline in the labor supply, increased healthcare costs, and challenges for emerging industries in smaller cities. It is important to study the impact of Canada's aging population trends on the economy to inform policy decisions aimed at promoting economic growth and stability in the face of demographic change.

Humanity has almost won its battle with many infectious diseases, thus increasing longevity, but is now confronted with challenges arising from population aging (1). A blessing turned into a curse as modern societies began struggling with prosperity diseases proliferation (2). Such obstacles are notable in the largest Western Balkan country (1). One-fifth of the Serbian population is aged 65, where that age group holds 8% globally (3). Serbia has a negative population growth and descending fertility rates, which places its population among the oldest in Europe (4). Following these trends, it is estimated that population older than 75 will make up amajority in the next two decades forming a T shaped age pyramid (5). Within the broader South East European region, population aging trend is clearly present for decades and shows clear signs of acceleration (6). This phenomenon originated from tumultuous changes in terms of political and economic stability affecting the Balkans in past decades. During the civil war in the 1990s, there has been an exodus of refugees from former parts of Yugoslavia to Serbia. This influx of people accounted for 5% of the total Serbian population count, but left no positive mark on the overall fertility rates due to similar reproductive behavior of internally displaced people (7). Destitution caused by sanctions placed by the Security Council of the UN forced indigenous people to embark on massive emigrations toward richer and more viable economies. Additional impacts on renewal of demographic potential were “brain drain” consisting of almost 50% of skilled emigrants younger than 40 (8). Difficulties in finding a partner of the opposite sex are also noteworthy. Even though the ratio of men and women is even at reproductive age, the proportion of each gender in rural and urban settings is significantly off-balance (9). Also, the age for womenwhen couples decide on having their first child has shifted from 25 in 2001 to 27 in 2011 (5).