Age Structure Of Population Research Articles

Hierarchical Bayesian Integrated Modeling of Age- and Sex-Structured Wildlife Population Dynamics

AbstractBiodiversity of large wild mammals is declining at alarming rates worldwide. It is therefore imperative to develop effective population conservation and recovery strategies. Population dynamics models can provide insights into processes driving declines of particular populations of a species and their relative importance. But there are insufficient tools, namely population dynamics models for wild herbivores, for characterizing their decline and for guiding conservation and management actions. Therefore, we have developed a model which can serve as a tool to fill that void. Specifically, we develop an integrated Bayesian state-space population dynamics model for wildlife populations and illustrate it using a topi population inhabiting the Greater Mara-Serengeti Ecosystem in Kenya and Tanzania. The model integrates ground demographic survey with aerial survey monitoring data. It incorporates population age and sex structure and life history traits and strategies and relates birth rates, age-specific survival rates and sex ratios with meteorological covariates, prior population density, environmental seasonality and predation risk. It runs on a monthly time step, enabling accurate characterization of reproductive seasonality, phenology, synchrony and prolificacy of births, juvenile and adult recruitments. Model performance is evaluated using balanced bootstrap sampling and by comparing model predictions with empirical aerial population size estimates. The hierarchical Bayesian model is implemented using MCMC methods for parameter estimation, prediction and inference and reproduces several well-known features of the Mara topi population, including striking and persistent population decline, seasonality of births, juvenile and adult recruitments. It is general and can be readily adapted for other wildlife species and extended to incorporate several additional useful features. Supplementary materials accompanying this paper appear on-line.

Social vs. individual age-dependent costs of imperfect vaccination

In diseases with long-term immunity, vaccination is known to increase the average age at infection as a result of the decrease in the pathogen circulation. This implies that a vaccination campaign can have negative effects when a disease is more costly (financial or health-related costs) for higher ages. This work considers an age-structured population transmission model with imperfect vaccination. We aim to compare the social and individual costs of vaccination, assuming that disease costs are age-dependent, while the disease’s dynamic is age-independent. A model for pathogen deterministic dynamics in a population consisting of juveniles and adults, assumed to be rational agents, is introduced. The parameter region for which vaccination has a positive social impact is fully characterized and the Nash equilibrium of the vaccination game is obtained. Finally, collective strategies designed to promote voluntary vaccination, without compromising social welfare, are discussed.

A GIS methodology for mapping regional and community vitality for Canada using the CanEcumene 3.0 Geodatabase with census data

Many ecosystem-based management (EBM) and related applications require integrating geospatial information about socio-economic conditions of human populated areas within a study area. However, integrating socio-economic data in such a way that it can be related to ecological data is challenging due to issues associated with spatial representation between socio-economic and ecological data frameworks. In Canada, this problem is particularly acute given its large geographic size, diversity of environments and highly irregular population distribution. Although several indices have been developed for Canada related to well-being and vulnerability, their suitability for EBM-related applications is limited. This article presents a GIS-based methodology for mapping regional and community vitality index (RVI/CVI) for Canada using standard Census data integrated with the CanEcumene 3.0 Geospatial Database (GDB). The method uses percentile ranks of five sub-indicators of vitality covering population growth, age structure, education, employment and economic wealth. Results reveal a number of notable patterns and trends in socio-economic conditions across the country and across different types of communities and regions. Most notable are decreasing CVI values from economic core regions to rural and remote communities; decreasing scores from high population centres to lower populated areas and lower scores for Indigenous communities when compared with non-Indigenous communities. A series of maps show variation in RVI/CVI values for specific locations with changes over time.

Excess deaths and loss of life expectancy attributed to long-term NO2 exposure in the Chinese elderly

BackgroundEvidence linking nitrogen dioxide (NO2) air pollution to life span of high-vulnerability older adults is extensively scarce in low- and middle-income countries. This study seeks to quantify mortality risk, excess deaths, and loss of life expectancy (LLE) associated with long-term exposure to NO2 among elderly individuals in China. MethodsA nationwide dynamic cohort of 20352 respondents ≥65 years old were enrolled from the China Longitudinal Health and Longevity Survey during 2005–2018. Residential exposures to NO2 and co-pollutants were assessed by well-validated spatiotemporal prediction models. A Cox regression model with time-dependent covariates was utilized to quantify the association of all-cause mortality with NO2 exposure, controlling for confounders such as demographics, lifestyle, health status, and ambient temperature. NO2-attributable deaths and LLE were evaluated for the years 2010 and 2020 based on the pooled NO2-mortality relation derived from multi-national cohort investigations. Decomposition analyses were conducted to dissociate net shift in NO2-related deaths between 2010 and 2020 into four primary contributing factors. ResultsA total of 14313 deaths were recorded during follow-up of approximately 100 hundred person-years (median 3.6 years). We observed an approximately linear relationship (nonlinear P = 0.882) of NO2 exposure with all-cause death across a broad range from 6.6 to 95.7 μg/m3. Every 10-μg/m3 rise in yearly average NO2 concentration was linked to a hazard ratio (HR) of 1.045 (95% confidence interval [CI]: 1.031–1.059). In the updated meta-analysis of this study and 9 existing cohorts, we estimated a pooled HR of 1.043 (95% CI: 1.023–1.063) for each 10-μg/m3 growth in NO2. Reaching a 10-μg/m3 counterfactual target of NO2 concentration in China could avoid 0.33 (95% empirical CI: 0.19–0.49) million premature deaths and an LLE of 0.40 (95% empirical CI: 0.23–0.59) years in 2010, which greatly dropped to 0.24 (95% empirical CI: 0.14–0.36) million deaths and 0.21 (95% empirical CI: 0.12–0.31) years of LLE in 2020. The net fall in NO2-attributable deaths (–26.8%) between 2010 and 2020 was primarily driven by the declines in both NO2 concentration (–41.6%) and mortality rate (–27.1%) under population growth (+41.0%) and age structure transition (+0.9%). ConclusionsOur findings provide national evidence for increased risk of premature death and loss of life expectancy attributed to later-life NO2 exposure among the elderly in China. In an accelerated aging society, strengthened clean air actions should be formulated to minimize the health burden and regional inequality in NO2-attributable mortality.

Use of Fin Rays and Fin Spines in Nonlethal Age Estimation of Florida Bass

Abstract Nonlethal age-estimation methods for Florida Bass Micropterus salmoides using fin rays and spines would enhance trophy-bass research, management, and conservation. Nonlethal removal of fin structures would also expand opportunities for collecting age-related information, specifically during small-population projects as well as tournaments and citizen-science programs, for which sacrificing fish is not an option. We assessed the bias of age estimates derived from Florida Bass anal-, pelvic-, dorsal-, and pectoral-fin rays and anal-, pelvic-, and dorsal-fin spines by comparing them to age estimates derived from otoliths (i.e., sagittae), which are the standard for ageing Florida Bass. We evaluated the precision of age estimates by calculating the absolute difference between replicate reads of each ageing structure for each reader. Linear-mixed effects model selection indicated that precision was most affected by age, structure, and the age*structure interaction, in which the effect of age varied by structure. Age estimates from otoliths were the most precise whereas pelvic spines were the least precise among all structures examined. Bias was similar across all fin structures, but the effect of age on bias varied by reader. Marginal increment analysis indicated that annulus formation was completed from November to March in Florida Bass dorsal spines, 5 months earlier than in Florida Bass otoliths. Our results suggest that nonlethally removed fin structures, especially dorsal spines, have potential for use in estimating age, growth rates, mortality, and age structure of bass populations, which could be particularly beneficial where bass can reach unusual trophy sizes.

THE TRANSFORMATION IN THE AGE STRUCTURE OF THE POPULATION OF UKRAINE IN THE YEARS 2001-2021: GENDER AND INTERREGIONAL ASPECTS

The territorial and gender differences of the transformational process in the age structure of the Ukrainian population during the 20-years’ period are analyzed in the article. The key factors and tendencies in age structure in various regions are determined. The comparative analysis of its changes among urban and country-side population is performed. The general tendency characterizing the age structure of the urban and country-side population of Ukraine is pointed out – that is the decrease in the share of the younger than active work force, and the increase in the share of the senior citizens. In the present-day structure of the urban population every fourth citizen represents the 60+ age group. The differences in the degree and intensity of aging of the rural and urban population are shown. The index of aging among urban population is much higher and makes 175,6% against 146,9% on the rural territory. The intensification of the process of demographic aging by gender is proven. In 2021, in the total number of population of Ukraine the share of men in the 60+ age group was 36,1%, while the share of women of the same age group was 63,9%. In the years 2001- 2021, the share of women at post-workable age grew to 29,5% of the total number of female population, and that of men grew to 19,3% of the total number of male population. The growth in the share of women and men at post-workable age in the urban area and its decline in the rural area are indicated. Interregional differences in the transformational process in the age structure of the Ukrainian population are defined. The smallest share of the citizens in post-workable age is observed in Volyn, Rivne, and Transcarpathean regions. The biggest share of the citizens in post-workable age is observed in Luhansk, Donetsk, Chernihiv, Sumy, Cherkasy, Zaporizhzhia, Kirovohrad, and Poltava regions. The chare of the workable age citizens is growing in 22 administrative units of Ukraine. The consequences of the transformation in the age structure of population are evaluated. The hypothesis has been proven that the age structure changes are correlated with the share of women at reproductive age, and demographic load. The decrease in the share of workable population was caused by the decrease in the share of women at reproductive age from 48,4% to 43,4%. In the years 2000 – 2021 the demographic load on the workable population grew mainly due to the older age group population (in 2021 the demographic load difference between children and the retired was 148 people). The demographic load on the workable population is 7,8% higher in the rural area than in the urban. The attention is drawn to the necessity of taking into consideration territorial peculiarities in the process of transformation in the population age structure when substantiating national programs and measures of active demographic policy. The regions of Ukraine characterized by low economic development are facing the biggest hardships in the adaptation process towards the changes of population age structure. Key words: transformation in the age structure of population, urban and rural population, demographic aging, demographic load.

The burden, causes, and determinants of blindness and vision impairment in Asia: An analysis of the Global Burden of Disease Study.

Asia accounts for more than half of the world's population and carries a substantial proportion of the global burden of blindness and vision impairment. Characterising this burden, as well as its causes and determinants, could help with devising targeted interventions for reducing the occurrence of blindness and visual impairment. Using the Global Burden of Disease Study 2019 database, we retrieved data on the number of disability-adjusted life years (DALYs); crude and age-standardised rates; and the prevalence (with 95% uncertainty intervals (95%UIs)) of blindness and vision loss due to six causes (age-related macular degeneration, cataracts, glaucoma, near-vision impairment, refractive error, and other vision loss) for Asian countries for the period between 1990 and 2019. We defined DALYs as the sum of the years lost due to disability and years of life lost, and calculated age-standardised figures for the number of DALYs and prevalence by adjusting for population size and age structure. We then evaluated the time trend of the disease burden and conducted subgroup analyses by gender, age, geographic locations, and socio-demographic index (SDI). In 2019, the DALYs and prevalence of blindness and vision loss had risen by 90.1% and 116% compared with 1990, reaching 15.84 million DALYs (95% UI = 15.83, 15.85) and 506.71 million cases (95% UI = 506.68, 506.74). Meanwhile, the age-standardised rate of DALYs decreased from 1990 to 2019. Cataracts, refractive error, and near vision impairment were the three most common causes. South Asia had the heaviest regional disease burden (age-standardised rate of DALYs = 517 per 100 000 population; 95% UI = 512, 521). Moreover, the burden due to cataracts ranked high in most Asian populations. Being a woman; being older; and having a lower national SDI were factors associated with a greater vision loss burden. The burden due to vision loss remains high in Asian populations. Cataracts, refractive error, and near vision loss were the primary causes of blindness and vision loss. Greater investment in ocular disease prevention and care by countries with lower socioeconomic status is needed, as well as specific strategies targeting cataract management, women and the elderly.

Growth and longevity of the endangered freshwater pearl mussel (Margaritifera margaritifera): Implications for conservation and management

AbstractKey life‐history data, such as growth and age, are necessary to effectively manage and conserve threatened freshwater mussel species. Traditionally growth and age studies require large yet destructive sample sizes covering all age classes. Such methods pose a risk to populations of conservation concern, and therefore, alternative methods that need only limited sample sizes are necessitated to prevent further threats to such populations. We applied retrospective shell growth at age reconstructions to 98 critically endangered freshwater pearl mussel (FPM) individuals from 34 populations across Finland and Sweden, enabling the use of extremely small sample sizes (n = 1–6 per population). We compared the performance of six different growth models with the reconstructed size‐at‐age data across FPM juvenile (<20 years old) and adult life stages. The growth reconstruction model showed reasonable skill in reconstructing FPM growth patterns. The von Bertalanffy model showed to be a good general descriptor of growth for FPM, but it systematically underestimated the asymptotic size. The power law model was the most accurate in estimating juvenile growth (lowest deviances from the size‐at‐age data). FPM showed great variability in longevity (Amax = 54–254 years) and growth constant k (0.018–0.057 year−1). Our results show that reasonable estimates of growth can be attained even when sample sizes are extremely limited. The results can be further applied to gain knowledge on the population's age structure, size at maturation, and recovery potential. The methodology is applicable to other freshwater mussel species of conservation concern.

Demographics and Emissions: The Life Cycle of Consumption Carbon Intensity

The consumption carbon intensity – defined as the carbon emissions per unit of consumption – varies with age: it is hump‐shaped over the life cycle, but becomes flatter at high levels of income. We document this novel fact using US household‐level consumption data. This relationship holds not only at the individual level, but also at the aggregate: we leverage information across US states and countries all around the world to show that the carbon intensity of the economy depends on the population age structure. Consequently, policy changes that alter carbon prices affect relatively more middle‐age individuals, and especially so in low‐income economies.

Population Change and Residential Segregation in Italian Small Areas, 2011–2021: An Analysis With New Spatial Units

This article explores spatial patterns of demographic change and residential segregation in Italy over the past decade, a topic which has not been studied in detail in the literature. Population ageing and migration are unfolding rapidly in a number of European countries, generating tensions and challenges at local level. Aggregate regional or national statistics can conceal significant variations at local level, which are of considerable interest and relevance. This is particularly the case in Italy, where spatial heterogeneity and regional disparities are marked. The analysis presented in this paper uses a new source of data derived from large public archives, which permits comparisons to be made at local level with the 2011 census of population. In this way, it is possible to map out and to analyse demographic trends at a fine level of spatial definition. In order to exploit the potential of these data, the authors use a new set of spatial units which were derived by applying automatic rezoning procedures. These output areas are well suited to the study of the age structure of local populations, population change, and migration in a uniform way across the entire national territory, as the empirical results confirm.

Modeling Population Growth under Climate Stressors Using Age-Structured Matrix Models.

Climate resilience, a focus of many recent studies, has been examined from ecological, physiological, and evolutionary perspectives. However, sampling biases toward adults, males, and certain species have made establishing the link between environmental change and population-level change problematic. Here, we used data from four laboratory studies, in which we administered pre- and postnatal stressors, such as suboptimal incubation temperature, heat stress, and food restriction, to zebra finches. We then quantified hatching success, posthatch survival, and reproductive success, to parameterize age-structured population dynamics models with the goal of estimating the effect of the stressors on relative population growth rates. Using the same model structure, we tested the hypothesis that early life stages influence population growth rate more than later life stages. Our models suggested that stressful events during embryonic development, such as suboptimal incubation temperatures and reduced gas exchange for the embryos, have a greater total impact on population growth than posthatch stressors, such as heat stress and food restriction. However, among life history traits, differences in hatching success and sex ratio of offspring in response to stressors changed population growth rates more than differences in any other demographic rate estimates. These results suggest that when predicting population resilience against climate change, it is critical to account for effects of climate change on all life stages, including early stages of life, and to incorporate individuals' physiology and stress tolerance that likely influence future stress responses, reproduction, and survival.

Analysis of the global burden of cervical cancer in young women aged 15-44 years old.

Understanding the burden of cervical cancer (CC) in young women aged 15-44 years old are essential for formulating effective preventive strategies. Utilizing the Global Burden of Disease 2019 Study, we estimated incidence, disability-adjusted life-years (DALYs), years of life lost (YLLs) and years lived with disability (YLDs) due to CC among young women from 1990 to 2019. Additionally, we evaluated the temporal trends using estimated annual percentage changes (EAPCs) during this period. We conducted a decomposition analysis to assess the absolute contributions of three components: population growth, population age structure and epidemiologic changes. Globally, there were 187 609.22 incident cases of CC worldwide, resulting in 2621 917.39 DALYs in 2019. From1990 to 2019, the age-standardized rates were decline, only the age-standardized YLDs rate (EAPC = 0.02; 95% CI: -0.02 to 0.05) showed a stable trend. The largest increase in age-standardized incidence rate (ASIR) and age-standardized YLDs rate observed in the high-middle social demographic index (SDI) quintiles. Population growth and age structure changes were associated with substantial changes in cases of CC, especially in South Asia and East Asia. Globally, the burden of CC in young women continues to increase, as measured by the absolute number. As populations are growing and age structure changes were associated with substantial changes in cases of CC, governments will face increasing demand for treatment, and support services for CC, especially in South Asia and East Asia.

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

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

Coding Optimization for an Ecological non-linear Age-structured Fish Population Model with a Shepherd Recruitment Function

The study of the optimally density-regulated recruitment plays a crucial role in the overall management and determining of fishing efforts of marine fish populations. This paper will develop a Matlab code can determine what an optimal recruitment density regulation strategy would be for the un-fished population and what it changes to when fishing efforts are applied. This code can determine threshold values used to avoid fisheries from collapsing. The code will be applied to the Gulf of California Pacific sardine (Sardinops caeruleus) population. An age structured design with a Shepherd density regulating stock-recruitment function is used in this study. In this work, the parameter which is varied is captured in the Shepherd recruitment function and is associated with behavioral interventions such as selecting different drift routes and clumping on resources that will increase egg-larvae survival to the recruitment stage. A detailed background study of other models is explored, then a derivation of the Shepherd recruitment model is developed from the traditional discrete model. A special MATLAB code is then developed to illustrate the pair-wise invasive plots for the model structures. The code is for theoretical analysis of fish population models.

The burden of disease and economic growth: The nonlinear effect of population age structure

This study aims to detangle the impact of health on economic growth as empirical evidence shows a mixture of findings. We use data on the Burden of Disease (BoD) from the Institute of Health Metric Evaluation (IHME) to measure health capital and the economic data of 87 countries from 1990 to 2018. Using panel threshold regression, this study shows that the old dependency ratio is a good measure of the threshold variable, which divides the country groups into four. The BoD, whether it comes from communicable diseases (CD), non-communicable diseases (NCD), or injuries, has a negative impact on economic growth. However, the negative relation is somewhat diminished as the population gets older, demonstrating that the BoD's impact on economic growth is less pronounced for the older population than the younger population.

Modelled impact of Tiny Targets on the distribution and abundance of riverine tsetse.

The insecticide-treated baits known as Tiny Targets are one of the cheapest means of controlling riverine species of tsetse flies, the vectors of the trypanosomes that cause sleeping sickness in humans. Models of the efficacy of these targets deployed near rivers are potentially useful in planning control campaigns and highlighting the principles involved. To evaluate the potential of models, we produced a simple non-seasonal model of the births, deaths, mobility and aging of tsetse, and we programmed it to simulate the impact of seven years of target use against the tsetse, Glossina fuscipes fuscipes, in the riverine habitats of NW Uganda. Particular attention was given to demonstrating that the model could explain three matters of interest: (i) good control can be achieved despite the degradation of targets, (ii) local elimination of tsetse is impossible if invasion sources are not tackled, and (iii) with invasion and target degradation it is difficult to detect any effect of control on the age structure of the tsetse population. Despite its simplifications, the model can assist planning and teaching, but allowance should be made for any complications due to seasonality and management challenges associated with greater scale.

Study of Populations of Urtica dioica L. in the Mountain Areas of Nakhchivan Autonomous Republic

The distribution, ontogenetic structure, age and growth structure of hay meadow populations, productivity in different periods of ontogenesis of all populations of Urtica dioica L. are considered. Populations of this species are identified and studied. Urtica dioica is a common plant in the highlands of the Nakhchivan Autonomous Republic. An assessment of 10 populations was carried out, the data were presented in the form of tables and graphs. The structure of ontogenesis was studied based on the population method. It has been established that this plant is distributed as part of plant groups in the herbaceous, shrub and forest vegetation of the Sharur, Babek, Kengerli, Shahbuz and Ordubad administrative regions of the Nakhchivan Autonomous Republic.

A note on the compactness of the resolvent of the age-diffusion operator

The generator of the semigroup associated with linear age-structured population models including spatial diffusion is shown to have compact resolvent.

Socioeconomic inequalities in accumulation of multimorbidity in England from 2019 to 2049: a microsimulation projection study

There are socioeconomic inequalities in the prevalence of multimorbidity and its accumulation across the life course. Estimates of multimorbidity prevalence in English primary care increased by more than two-thirds from 2004 to 2019. We developed a microsimulation model to quantify current and projected multimorbidity inequalities in the English adult population. We used primary care data for adults in England from the Clinical Practice Research Datalink Aurum database between 2004 and 2019, linked to the 2015 English Index of Multiple Deprivation (IMD), to model time individuals spent in four health states (healthy, one chronic condition, basic multimorbidity [two or more chronic conditions], and complex multimorbidity [three or more chronic conditions affecting three or more body systems]) by sex, age, IMD quintile, birth cohort, and region. We applied these transition times in a stochastic dynamic continuous-time microsimulation model to Office for National Statistics population estimates for adults aged 30-90 years. We calculated projected prevalence and cumulative incident cases from 2019 to 2049 by IMD quintile, age group (younger than 65 years vs 65 years and older), and years to be lived without multimorbidity at age 30 years. Under the assumption that all chronic conditions were lifelong, and that once diagnosed there was no recovery, we projected prevalence of multimorbidity (basic or complex) increases by 34% from 53·8% in 2019 to 71·9% (95% uncertainty interval 71·8-72·0) in 2049. This rise equates to an 84% increase in the number of people with multimorbidity: from 19·2 million in 2019 to 35·3 million in 2049 (35·3 million to 35·4 million). This projected increase is greatest in the most deprived quintile, with an excess 1·07 million (1·04 million to 1·10 million) cumulative incident basic multimorbidity cases and 0·70 million (0·67 million to 0·74 million) complex multimorbidity cases over and above the projected cases for the least deprived quintile, largely driven by inequalities in those younger than 65 years. The median expected number of years to be lived without multimorbidity at age 30 years in 2019 is 15·12 years (14·62-16·01) in the least deprived IMD quintile and 12·15 years (11·61-12·60) in the most deprived IMD quintile. The number of people living with multimorbidity will probably increase substantially in the next 30 years, a continuation of past observed increases partly driven by changing population size and age structure. Inequalities in the multimorbidity burden increase at each stage of disease accumulation, and are projected to widen, particularly among the working-age population. Substantial action is needed now to address population health and to prepare health-care and social-care systems for coming decades. University of Liverpool and National Institute for Health and Care Research School for Public Health Research.

Warmer autumns and winters could reduce honey bee overwintering survival with potential risks for pollination services

Honey bees and other pollinators are critical for food production and nutritional security but face multiple survival challenges. The effect of climate change on honey bee colony losses is only recently being explored. While correlations between higher winter temperatures and greater colony losses have been noted, the impacts of warmer autumn and winter temperatures on colony population dynamics and age structure as an underlying cause of reduced colony survival have not been examined. Focusing on the Pacific Northwest US, our objectives were to (a) quantify the effect of warmer autumns and winters on honey bee foraging activity, the age structure of the overwintering cluster, and spring colony losses, and (b) evaluate indoor cold storage as a management strategy to mitigate the negative impacts of climate change. We perform simulations using the VARROAPOP population dynamics model driven by future climate projections to address these objectives. Results indicate that expanding geographic areas will have warmer autumns and winters extending honey bee flight times. Our simulations support the hypothesis that late-season flight alters the overwintering colony age structure, skews the population towards older bees, and leads to greater risks of colony failure in the spring. Management intervention by moving colonies to cold storage facilities for overwintering has the potential to reduce honey bee colony losses. However, critical gaps remain in how to optimize winter management strategies to improve the survival of overwintering colonies in different locations and conditions. It is imperative that we bridge the gaps to sustain honey bees and the beekeeping industry and ensure food and nutritional security.