Changes In Population Structure Research Articles

A palaeogenomic investigation of overharvest implications in an endemic wild reindeer subspecies.

Overharvest can severely reduce the abundance and distribution of a species and thereby impact its genetic diversity and threaten its future viability. Overharvest remains an ongoing issue for Arctic mammals, which due to climate change now also confront one of the fastest changing environments on Earth. The high-arctic Svalbard reindeer (Rangifer tarandus platyrhynchus), endemic to Svalbard, experienced a harvest-induced demographic bottleneck that occurred during the 17-20th centuries. Here, we investigate changes in genetic diversity, population structure, and gene-specific differentiation during and after this overharvesting event. Using whole-genome shotgun sequencing, we generated the first ancient and historical nuclear (n = 11) and mitochondrial (n = 18) genomes from Svalbard reindeer (up to 4000 BP) and integrated these data with a large collection of modern genome sequences (n = 90) to infer temporal changes. We show that hunting resulted in major genetic changes and restructuring in reindeer populations. Near-extirpation followed by pronounced genetic drift has altered the allele frequencies of important genes contributing to diverse biological functions. Median heterozygosity was reduced by 26%, while the mitochondrial genetic diversity was reduced only to a limited extent, likely due to already low pre-harvest diversity and a complex post-harvest recolonization process. Such genomic erosion and genetic isolation of populations due to past anthropogenic disturbance will likely play a major role in metapopulation dynamics (i.e., extirpation, recolonization) under further climate change. Our results from a high-arctic case study therefore emphasize the need to understand the long-term interplay of past, current, and future stressors in wildlife conservation.

Click-click, who’s there? Acoustically derived estimates of sperm whale size distribution off western Ireland

Understanding the structure of populations is a critical element to the establishment of management and conservation measures. Sperm whales Physeter macrocephalus are characterised by a demographic spatial segregation, associated with a conspicuous sexual dimorphism reflected in their vocalisations. These characteristics make acoustic techniques very relevant to the study of sperm whale population structure, especially in remote, challenging environments. The reliability of using inter-pulse intervals of sperm whale clicks to infer body size has long been verified and extensively used. We provide the first size structure estimates of the sperm whale population in an area where assumptions on population structure mainly relied on sparse observations at sea, whaling records and stranding data. Over 10,000 hours of acoustic data collected using both static acoustic recorders and towed hydrophone arrays in Irish offshore waters were processed using a machine learning-based tool aimed at automatically extracting inter-pulse intervals from sperm whale recordings. Our analyses suggested that, unlike previously thought, large males would not account for the majority of the animals recorded in the area. We showed that adult females/juvenile males (length 9-12 m) were predominant, accounting for 49% (n = 788) of the number of individuals recorded (n = 1,595), while the proportions of immature individuals (length<9 m) and adult males (length >12 m) were well balanced, accounting for 25% (n = 394) and 26% (n = 413) of the recorded whales, respectively. Our data also suggested some size segregation may be occurring within the area, with smaller individuals to the south. The implications of such findings are crucial to the management of the population and provide an important baseline to monitor changes in population structure, particularly relevant under changing habitat conditions.

Future Projections of Global Plastic Pollution: Scenario Analyses and Policy Implications

Plastic pollution has attracted the attention of the media, public, and government worldwide. Analysis of the inverted U-shaped environmental Kuznets curve (EKC) relationship between economic development and plastic pollution is crucial because economic growth is a critical driver of plastic pollution. In this study, for the first time, we (i) used the stochastic impacts of regression on population, affluence, and technology (STIRPAT) model to investigate the EKC relationship; (ii) performed a comprehensive analysis of the effects of sociodemographic factors on plastic pollution; and (iii) used a panel dataset of 128 countries for empirical analyses. The STIRPAT model was used to conduct scenario analyses to explore the impacts of sociodemographic driving forces on future plastic pollution by 2050 on a national (217 countries) and global scale. The empirical results confirmed the EKC relationship and revealed that changes in population structure and urbanization could substantially affect plastic pollution. Global plastic pollution was projected to reach 66.1 MT/y by 2050 under the business-as-usual scenario. Low-income countries and sub-Saharan Africa are projected to become major contributors to plastic pollution, leading to a global trend of increasing plastic pollution. These findings will help policymakers identify targets to effectively reduce future global plastic pollution.

Population structure and microscale morphological differentiation in a freshwater snail from the Chilean Altiplano

BackgroundThe diversity and population genetic structure of many species have been shaped by historical and contemporary climatic changes. For the species of the South American Altiplano, the historical climatic changes are mainly related to the wet events of great magnitude and regional influence that occurred during the Pleistocene climatic oscillations (PCOs). In contrast, contemporary climate changes are associated with events of lesser magnitude and local influence related to intensifications of the South American Summer Monsoon (SASM). Although multiple studies have analyzed the effect of PCOs on the genetic patterns of highland aquatic species, little is known about the impact of contemporary climate changes in recent evolutionary history. Therefore, in this study, we investigated the change in population structure and connectivity using nuclear and mitochondrial markers throughout the distribution range of Heleobia ascotanensis, a freshwater Cochliopidae endemic to the Ascotán Saltpan. In addition, using geometric morphometric analyses, we evaluated the concomitance of genetic divergence and morphological differentiation.ResultsThe mitochondrial sequence analysis results revealed the presence of highly divergent co-distributed and geographically nested haplotypes. This pattern reflects an extension in the distribution of groups that previously would have differentiated allopatrically. These changes in distribution would have covered the entire saltpan and would be associated with the large-scale wet events of the PCOs. On the other hand, the microsatellite results defined five spatially isolated populations, separated primarily by geographic barriers. Contemporary gene flow analyses suggest that post-PCO, climatic events that would have connected all populations did not occur. The morphometric analyses results indicate that there is significant morphological differentiation in the populations that are more isolated and that present the greatest genetic divergence.ConclusionsThe contemporary population structure and morphological variation of H. ascotanensis mainly reflect the post-PCO climatic influence. Although both markers exhibit high genetic structuring, the microsatellite and morphology results show the preponderant influence of fragmentation in recent evolutionary history. The contemporary genetic pattern shows that in species that have limited dispersal capabilities, genetic discontinuities can appear rapidly, erasing signs of historical connectivity.

Using whole genome sequencing to characterize Clostridioides difficile isolates at a tertiary center in Melbourne, Australia.

Clostridioides difficile infection (CDI) is the commonest cause of healthcare-associated diarrhea and undergoes standardized surveillance and mandatory reporting in most Australian states and territories. Historically attributed to nosocomial spread, local and international whole genome sequencing (WGS) data suggest varied sources of acquisition. This study describes C. difficile genotypes isolated at a tertiary center in Melbourne, Australia, their likely source of acquisition, and common risk factors. Retrospective observational study. The Royal Melbourne Hospital (RMH), a 570-bed tertiary center in Victoria, Australia. Short-read whole genome sequencing was performed on 75 out of 137 C. difficile isolates obtained from 1/5/2021 to 28/2/2022 and compared to previous data from 8/11/2015 to 1/11/2016. Existing data from infection control surveillance and electronic medical records were used for epidemiological and risk factor analysis. Eighty-five (62.1%) of the 137 cases were defined as healthcare-associated from epidemiological data. On genome sequencing, 33 different multi-locus sequence type (MLST) subtypes were identified, with changes in population structure compared to the 2015-16 period. Risk factors for CDI were present in 130 (94.9%) cases, including 108 (78.8%) on antibiotics, 86 (62.8%) on acid suppression therapy, and 25 (18.2) on chemotherapy. In both study periods, most C. difficile isolates were not closely related, suggesting varied sources of acquisition and that spread of C. difficile within the hospital was unlikely. Current infection control precautions may therefore warrant review. Underlying risk factors for CDI were common and may contribute to the proportion of healthcare-associated infections in the absence of proven hospital transmission.

Ways to Enhance the Adaptability of Business English Majors in Higher Vocational Colleges

In the face of high-quality development requirements and changes in population structure, China's demand for highly skilled personnel is stronger. The professional setting of some vocational education is disjointed with the social needs, among which, the business English major in higher vocational colleges has prominent problems, the professional structure is not reasonable, and the adaptability is not strong, which restricts the economic and social development. This paper takes the business English major of Guangzhou Huanan Business College as an example, analyzes its current development situation and dilemma, and puts forward several strategies to enhance the adaptability of higher vocational education majors. This paper mainly adopts literature research, investigation method, case study, etc. By clarifying the orientation of “business trade plus English” majors, exploring the “three+two-stages” joint training mode, giving full play to the role of enterprise subjects as well as the dual subjects of schools and enterprises jointly educated people, actively expanding the cross-disciplinary advantages, creating major highlights, constructing the “four-double” foreign language business trade plus 321 talent mode, it constantly improves the adaptability of business English majors in higher vocational colleges, making the business English major better.

Trend and determinants of minimum dietary diversity consumption change among children aged 6-23 months in Ethiopia from 2011 to 2019: A multivariate decomposition analysis.

Sustainable Development Goals 2 target 2.2 aimed to end all forms of malnutrition by 2030. However, the prevalence of inadequate minimum dietary diversity (MDD) is high in Ethiopia and the evidence of trends and determinants of MDD consumption change among children over time is limited. Therefore, this study aimed to determine trends and determinants of MDD consumption change among children aged 6 to 23 months in Ethiopia from 2011-2019 Demographic and Health Survey (DHS) data. The study used the data on nationally representative weighted samples of 6,971, 7,467, and 3,154 children aged 6-23 months from the 2011, 2016, and 2019 rounds of the DHS. Trend and Multivariate Decomposition analysis was conducted to determine MDD consumption change from 2011-2016, and 2016-2019 into two components: one that was explained by differences in the level of the determinants (endowment), and the other component was explained by differences in the effect of the covariates on the outcome (coefficient effects). The trends analysis showed that adequate MDD consumption significantly increased from 2% to 10.41% from 2011 to 2016 but decreased from 10.41% to 7.11% from 2016 to 2019 in Ethiopia. The compositional and behavioral change factors like maternal age, occupational status of parents, sex of the household head, wealth index, residence, and sex of child statistically contributed to changes in MDD consumption from 2011 to 2016, and from 2016 to 2019 at p-value <0.05. The trend of minimum dietary diversity consumption among children aged 6 to 23 months in Ethiopia increased from 2011-2016 and decreased from 2016-2019 in the last decade. The study revealed that the changes in behavioral response and population composition contributed to MDD consumption change among children in Ethiopia. The finding highlights the urgent need for targeted interventions and policies to address the issue of MDD consumption change among young children due to population structure changes like wealth status, residence, and behavioral response related to employment, household head, and sex of the child in Ethiopia. Therefore, efforts should be geared to reduce poverty and improve maternal employment status, particularly for women, by producing equitable economic opportunities.

Pension’s Impact to the Subjective Well-being of Retirees

The aging population is a growing concern of many countries worldwide. The change in population structure has forced governments of these countries to actively deal with this problem. Many countries’ governments are taking measures to the aging population problem, and the pension system is one important way to ensure old people’s welfare by transfer payment from other parties of the society. This paper aims to conclude and discuss the mechanism about how pension affects the subjective well-being of retirees. It is important to fully understand the implications behind pension’s impact for policy makers to make wise decisions. Researchers found that pension mainly contributes to financial security and health situation, which are two important factors affecting subjective well-being of retirees. Financial security is enhanced by increased income, so that retirees can transfer payment to other family member and increase their own consume costs. The positive impact of pension to health situation are only significant for poor population.

Estimation of Premature Deaths due to Exposure to Particulate Matter (PM2.5) Reflecting Population Structure Change in South Korea

Estimation of Premature Deaths due to Exposure to Particulate Matter (PM_2.5) Reflecting Population Structure Change in South Korea

Reexamining the impact of financial development on ecological footprint: The roles of population aging, per capita GDP, and technological innovation

Existing research results on the impact of financial development on ecological footprint are inconsistent or even opposite. In order to better understand the impact of financial development on ecological footprint, this study explores the relationship between financial development and ecological footprint from the perspectives of population aging, GDP per capita, and technological innovation. The results show that when the population aging level is below the threshold, the coefficient of financial development on ecological footprint is 0.285, but when the aging level exceeds the second threshold, the coefficient of financial development on ecological footprint becomes faint negative. Similarly, after per capita GDP crosses the threshold, the correlation coefficient between financial development and ecological footprint turns from positive to faint negative. Compared to this, when the level of technological innovation is below the threshold, the coefficient of financial development and ecological footprint is 0.155, while when the level of technological innovation is above the threshold, the coefficient of financial development and ecological footprint is −0.597. The above results indicates that the impact of financial development on the ecological footprint is affected by other factors. Compared with changes in population structure (aging) and social wealth (GDP per capita), technological innovation has a greater impact on the relationship between financial development and ecological footprint.

EAST MEETS WEST: INNOVATIVE APPROACHES TO GERONTOLOGY EDUCATION AND TRAINING

Abstract The global population is aging at an increasingly fast pace compared to past generations. Although the magnitudes and rates of aging in the United States and Japan differ, the drastic change in population structure has resulted in common challenges for both countries. One challenge is preparing people and society for living a long life while promoting well-being in old age for everyone. Combating ageism, delivering accurate information about aging, and encouraging people to have a balanced view of the aging process are all important topics for living in an aging society. Therefore, gerontology education and training plays a critical role. In this symposium, we will present examples of current efforts and research findings on aging education and training in both the United States and Japan. The first presenter will discuss their efforts on promoting gerontology education through redesigning communities with interdisciplinary collaboration in Japan. The second presenter will explain gerontology curriculum and degree programs in Japan. The third presenter will introduce an international gerontology education course designed for United States graduate students. The last presenter will report findings from a scoping review on intergenerational activities in higher education. Implications for future gerontology education will also be discussed.

PATTERN RECOGNITION AND INNOVATION OF HOME-BASED CARE IN CHINA: FROM THE PERSPECTIVE OF MULTINATIONAL COMPARISON

Abstract The development trend of family structure’s miniaturization and nucleation in China and the overlapping occurrence of population aging and associated frailty and morbidities have created an urgent need for innovation in the home care service model. In this paper, home-based care is regarded as a dynamic pension method. Based on the analysis of dynamic changes in population structure and family structure, this paper uses multi-stage microsimulation technology to scientifically predict the evolution of the older adult population’s distribution state and multi-health state. This approach leads to early identification of the risks of various home-based care models in the process of family structure changes. Based on this, with reference to the home-based care model cases in China, Japan, Europe, and the United States, this paper proposes the innovation of the multi-health state and the “ integrated care at home” model for households with an aging resident and brings up the optimization plan of home-based care service for accelerating the aging process. Implications for policies and practices to support family members to realize this optimized home care model will be discussed.

How Does Energy Intake Change in China? A Life Cycle Perspective.

China's population is showing the characteristics of "fewer children" and "aging", which will have a long-term and far-reaching impact on the food and nutritional needs of China and the world. In this paper, adult equivalent scale (AES) variables representing the household population structure were introduced into the energy intake model to quantify the impact of population structure changes on energy intake and reveal the characteristics of energy intake changes in the life cycle of Chinese residents. It is found that the change in the population structure has a significant impact on the energy intake of urban households in China, and the elasticity is 0.446. The energy intake of Chinese elderly over the age of 60 shows a trend of first increasing and then decreasing, especially after the age of 65, which indicates that the aging will promote a decline in food consumption in China. The energy intake of 1-10-year-old children, 22-30 year old, and 40-45 year old women all showed a change of first a decrease and then an increase, which may be related to parents' care for young children and women with children's management of body size. The average household size expressed by the adult equivalent scales of energy consumption is 2.341, which is smaller than the 3.052 calculated by the population number. The conclusion indicates that the prediction of the food and nutritional demand should be adjusted according to the changes and differences in accordance with the intensification of "fewer children" and "aging", as well as the life cycle changes in residents' energy intake, which is conducive to the formulation of food and nutrition security policies.

Adaptation Centers for Migrants in the Context of Russian Migration Policy

Migration has become an integral part of sociocultural and economic dynamics, but the successful adaptation of migrants remains a priority to ensure the stability and development of society. As international migration continues to increase, greater understanding is needed of how migrant adaptation measures affect a country’s demographic indicators and prospects. In this connection, the need to create migration adaptation centers and to identify their role in the demographic development of the state is becoming urgent. This aspect of the study represents scientific novelty and complements knowledge about migration and demographic changes. The purpose of this research is to study the attitude of state and municipal employees to the problems of regulating migration processes and the creation of migration adaptation centers, identifying the main trends that require systemic changes and new approaches to migration. The concept of “demographic integration” is substantiated, reflecting the relationship and influence of successful adaptation of migrants on the demographic development of society, covering such aspects as changes in population structure, fertility, labor force and other demographic parameters that may be directly or indirectly related to the process of adaptation of migrants. Initial data: a pilot sociological study conducted among state and municipal employees who were trained under a professional development program in different regions of Russia. Data collection was carried out using the method of expert survey. The results of the study showed a multidirectional approach of state and municipal employees to key aspects of migration processes. The majority of respondents expressed support for the creation of migration adaptation centers, which indicates the need to provide migrants with knowledge and skills that would contribute to their more successful adaptation to Russian society. This factor emphasizes the importance of carefully developing adaptation educational programs and services of migration centers. Scientific contribution: the concept of “demographic integration” is introduced, in the context of which the role of migration adaptation centers in the demographic development of Russia is assessed and the need to take into account the social and demographic aspects of migration processes is emphasized. Scope of application: the results of the study can be used to develop and improve policies in the field of migration and adaptation of migrants, as well as to study the dynamics of demographic processes in Russia.

Impacts of in situ urbanisation on grain production: Evidence from the Yangtze River Delta, China

With the promotion of county-level urban–rural integrated development policies in China, counties in economically developed regions have achieved sound in situ urbanisation (ISU), resulting in changes in regional population and production structures. However, to date, relatively few studies have focused on the ISU process and the variation in regional grain production in the Yangtze River Delta (YRD). This study evaluated the ISU rate (ISUR) at the county level using the entropy based TOPSIS model, introduced a super efficiency slacks-based measure (SBM) model to calculate cropland production efficiency (CPE), and reflected the status of grain production from grain yield and CPE. Spatio-temporal dynamics of ISU and grain production were examined from 2000 to 2020, and the impact mechanism of ISU on the grain production were explored encompassing regional differences and spatiotemporal evolution. The ISUR of the YRD showed a high distribution in the east and low in the west, with all counties showing a continuous increase, and an average increase from 0.15 in 2010 to 0.33 in 2020. The most rapid increases occurred in northern Zhejiang, southern Jiangsu, and the coastal areas. The grain yield in the entire region was high in the north and low in the south, with a continuous increase in the north and a continuous decrease in the south. The CPE distribution changed from high in the south in 2000 to high in the north in 2020, with a higher growth rate in the north and a significant decrease in the south. The initial advancement of ISU promoted grain production. The plains with medium ISU levels showed the highest grain yield and CPE. Where the ISU level reached extremely high levels, it had a suppressive effect on grain production. In mountainous areas, the CPE and grain yield decreased during ISU. The findings of this study are of great value to policymakers in adjusting the regional agricultural production structure according to ISU stages to implement food security strategies in a regionally integrated manner.

A Study on the Influence of Economic Policy on Fertility Reduction and the Countermeasures Based on China and Foreign Policy

It has been confirmed that China's fertility rate has fallen below the fifth lowest globally and has fully entered the low fertility trap. There is an urgent need to increase the fertility rate. This paper mainly studies the causes of the gradual decline in fertility in China in recent years. It compares the subsidy measures taken by various countries to cope with the low fertility rate. It compares the living cost and economic policy system in China to analyze how China should raise the fertility rate. Through the analysis and summary of the literature, it is found that the reasons for the decrease in China's fertility rate year by year are that the explicit and implicit costs of birth and raising are too high, and the allocation of educational resources is unfair, resulting in low social identity and low happiness. With the gradual decrease of the fertility rate, the population structure changes, and the risk increases, making it difficult for the fertility rate to return to normal. Therefore, China should follow the Nordic countries' policies on parenting costs and social welfare, favor multi-child families, reduce parenting costs after childbirth, improve family happiness, and introduce economic support policies for child-rearing. At the same time, China should avoid the policy risk of "only giving money" and avoid the ineffective phenomenon of increasing welfare but declining fertility rates instead of rising.

Aging, education and some other implications for the silver dividend in developing countries: Evidence from Brazil

Population aging increases dependency levels and can influence the transition from working life to retirement. Changes in population structure have important economic effects, which can be positive when analyzing the impacts of a more educated older labor force but could also impact families and governments. It is important to consider how age and education composition are associated with each other in contexts marked by high levels of inequality. In this paper, we analyze the economic consequences of the aging process in Brazil considering the role of improvements in education and the possibility of the constitution of a silver dividend in the country. We use a series of simulation models, based on the determinants of labor supply and labor income of people aged 45 years and over, to investigate the impacts of changes in the educational composition of the labor force. Our simulations show that the positive association between education, labor supply, and labor income would be more pronounced in scenarios of higher levels of education, labor market stability (high status activities and informality reduction), and changes in retirement rules, specifically the establishment of minimum ages. Such a context would increase the number of older workers and improve productivity, allowing appropriate conditions for the development of a silver dividend in Brazil in a quantitative and a qualitative way.

Population age structure – An underlying driver of national, regional and urban economic development

Abstract This paper argues that population age structure plays a significant role alongside institutional, technological, political, and cultural factors when it comes to explaining shifts in urban, regional and national economic development. The paper demonstrates how demographic transitions lead to changes in population age structure which in turn correlate with global shifts in economic development from 1950 onwards. It then analyzes the role of population age structure at the sub-national level by reviewing some prominent cases of regional and urban shifts in Western Europe and North America. Population size, population density and migration have always been an integrated part of economic geography, and the consequences of ageing in national and regional economies are increasingly being studied. The specific role of population age structure as a driver of economic development has, however, so far largely been ignored in the field.

Estimated impact of the UK soft drinks industry levy on childhood hospital admissions for carious tooth extractions: interrupted time series analysis

IntroductionTooth extraction due to dental caries is associated with socioeconomic deprivation and is a major reason for elective childhood hospital admissions in England. Consumption of sugar-sweetened beverages is a risk...

Health Burden and Driving Force Changes Due to Exposure to PM2.5 and O3 from 2014 to 2060 in a Typical Industrial Province, China

While air quality in China has improved significantly in recent years, the population is becoming increasingly vulnerable to air pollution due to the aging population. In this study, we assessed premature deaths attributable to long- and short-term exposures to PM2.5 and O3, as well as their driving forces in Shandong from 2014 to 2060 based on county-level near-real-time air pollutant concentration datasets and projected concentrations of PM2.5 and O3. We found that the concentrations of PM2.5 and O3 in most districts and counties from Shandong are still higher than the corresponding concentration limit of Grade II. Premature mortality caused by long- and short-term exposures to PM2.5 decreased by 13,045 and 8092 in 2020 compared with those in 2014, respectively. Furthermore, premature mortality attributable to short-term exposure to O3 was 36.08% higher than that due to short-term exposure to PM2.5 in 2020. The results of the driving force analysis indicate that the health benefits brought about by the improvement in air quality have been offset by the changes in population age structure. In the future, the increase in O3 concentration and population aging are the top two driving forces having adverse effects on the health burden. This study provides support for controlling the health risks of PM2.5 and O3 pollution, especially for the development of dual-pollutant concentration targets and synergistic control strategies.