Ergodicity of age structure in populations with Markovian vital rates, III: Finite-state moments and growth rate; an illustration

1977 ◽  
Vol 9 (3) ◽  
pp. 462-475 ◽  
Author(s):  
Joel E. Cohen
Keyword(s):  
Age Structure ◽  
Total Population ◽  
Age Groups ◽  
Linear Integral Equation ◽  
Vital Rates ◽  
Single Sex ◽  
Long Run ◽  
Finite State ◽  
Finite Set ◽  
Linear Integral

Leslie (1945) models the evolution in discrete time of a closed, single-sex population with discrete age groups by multiplying a vector describing the age structure by a matrix containing the birth and death rates. We suppose that successive matrices are chosen according to a Markov chain from a finite set of matrices. We find exactly the long-run rate of growth and expected age structure. We give two approximations to the variance in age structure and total population size. A numerical example illustrates the ergodic features of the model using Monte Carlo simulation, finds the invariant distribution of age structure from a linear integral equation, and calculates the moments derived here.

Ergodicity of age structure in populations with Markovian vital rates, III: Finite-state moments and growth rate; an illustration

1977 ◽  
Vol 9 (03) ◽  
pp. 462-475 ◽  
Author(s):  
Joel E. Cohen
Keyword(s):  
Age Structure ◽  
Total Population ◽  
Age Groups ◽  
Linear Integral Equation ◽  
Vital Rates ◽  
Single Sex ◽  
Long Run ◽  
Finite State ◽  
Finite Set ◽  
Linear Integral

Leslie (1945) models the evolution in discrete time of a closed, single-sex population with discrete age groups by multiplying a vector describing the age structure by a matrix containing the birth and death rates. We suppose that successive matrices are chosen according to a Markov chain from a finite set of matrices. We find exactly the long-run rate of growth and expected age structure. We give two approximations to the variance in age structure and total population size. A numerical example illustrates the ergodic features of the model using Monte Carlo simulation, finds the invariant distribution of age structure from a linear integral equation, and calculates the moments derived here.

Impact of the War in Croatia (1991-1995) on the Differentiation of Age Structure between Serbs and Croats: A Case Study of the Banija Region

2021 ◽  
pp. 1-17
Author(s):  
Aleksandar Kovjanić ◽  
Mila Pavlović ◽  
Vedran Živanović ◽  
Filip Krstić
Keyword(s):  
Age Structure ◽  
Scientific Community ◽  
Total Population ◽  
Population Aging ◽  
Population Decline ◽  
Age Groups ◽  
Economic Conditions ◽  
The Subject ◽  
The Impact

Abstract Aging is the subject of various studies by the scientific community and monitoring by responsible institutions. The intensity of aging and the proportion of age groups among various communities differ due to different socio-economic conditions and characteristics. This article researches the impact of the war in Croatia 1991–1995 and postwar living conditions on the divergence of population aging in the ethnically heterogeneous Banija region. The first postwar census in 2001 recorded a population decline of 44.9% compared to the 1991 census. We analyze the effects of the war on changes in ethnic and age structure, as well as their interrelations. The quantitative and qualitative magnitude of these demographic changes in the inter-census period had a decisive influence on the correlation of age and ethnic structure. The article examines whether the relative share of Serbs or Croats in the total population of a settlement affects the average age of the settlement. The results confirmed that the Serbs are older than the Croats, and are in the phase of the most advanced demographic age. These changes raise the question of the demographic future and the biological viability of the Serbs, who were the majority in the region before the war.

scholarly journals Three Economic Myths about Ageing: Participation, Immigration and Infrastructure

2020 ◽  
Author(s):  
Cameron Murray
Keyword(s):  
Economic Growth ◽  
Older People ◽  
Natural Resources ◽  
Age Structure ◽  
Total Population ◽  
Population Level ◽  
Population Ageing ◽  
Successful Result ◽  
Long Run ◽  
Modern Era

Population ageing due to longevity is one of the greatest successes of the modern era. However, it is widely thought to dramatically reduce workforce participation and overall output resulting in significant economic costs.This widely held view is wrong. Ageing countries have higher economic growth and the improved health and longevity of older people increases their economic contributions.High immigration is also thought to combat population ageing and be a remedy for these non-existent costs of ageing.This is wrong. Low immigration can affect the age structure by helping to stabilise the population, but high immigration has almost no long-run effect besides increasing the total population level. This creates bigger problems in the future.It is also widely thought that simply investing in infrastructure will accommodate high immigration and population growth at little cost.This too is wrong.Diseconomies of scale are a feature of rapid infrastructure expansion due to (1) the need to retrofit built-up cities, (2) the dilution of irreplaceable natural resources, and (3) the scale of investment relative to the stock of infrastructure.This ageing-immigration-infrastructure story is wrong on all three of its major points. Population ageing should be seen as the successful result of improvements in medical and health practices that have improved longevity and fostered a long-lived and economically productive society.

The population age structure and reproductive biology of Gyrodactylus salaris Malmberg (Monogenea)

Parasitology ◽  
1994 ◽  
Vol 108 (2) ◽  
pp. 167-173 ◽  
Author(s):  
P. D. Harris ◽  
P. A. Jansen ◽  
T. A. Bakke
Keyword(s):  
Age Structure ◽  
Total Population ◽  
Morphological Variability ◽  
Age Groups ◽  
Exponential Model ◽  
Population Age Structure ◽  
Mortality Schedule ◽  
Wide Range ◽  
Specific Mortality ◽  
Best Fit

SUMMARYGyrodactylus salaris has recently become a major pathogen of Atlantic Salmon (Salmo salar) in Norway. The survivorship, population age structure and pattern of insemination of G. salaris were studied to determine the extent to which this species reproduces sexually. The age-specific mortality schedule of G. salaris could be described by an exponential model but day to day variations were large, with an increase in mortality after each birth. Modelling population growth using the best fit mortality schedule indicated that, at stable age structure, 35% of the population would consist of newborn and pre-1st birth flukes. Using testis, penis and embryo development, pre-1st birth and immediately post-1st birth flukes could be unambiguously identified, and established infections were found to contain 35% pre-1st birth flukes, as predicted. The proportion of pre-1st birth flukes in newly established infections was significantly smaller, probably because of differences in the rate of transmission between newborn and older flukes. Gyrodactylus salaris is relatively long-lived, and more than 40% of the population may survive to give birth for the third time. As gyrodactylids are protogynous, and the first daughter is probably produced asexually, this long-lived strategy ensures that a large part of the G. salaris population possesses a functional male system, and that the asexually derived flukes are a smaller component of the total population in this species. Flukes with whorls of inseminated spermatozoa within the seminal receptacle were found in all age groups possessing a functional male system, and were interpreted as having been cross-inseminated. G. salaris on susceptible Norwegian salmon appears to regularly reproduce sexually, possibly accounting for its morphological variability and wide range of potential salmonid hosts.

scholarly journals The dynamics of sex-age structure of the population in urban and rural areas in the Republic of Kazakhstan in the years 1991-2013

2016 ◽  
Vol 31 (31) ◽  
pp. 87-111 ◽  
Author(s):  
Gulnara Nyussupova ◽  
Aisulu Kalimurzina
Keyword(s):  
Age Structure ◽  
Rural Areas ◽  
Rural Population ◽  
Total Population ◽  
Statistical Data ◽  
Economic Status ◽  
Age Groups ◽  
Working Age ◽  
The Republic ◽  
Urban And Rural Areas

Abstract In this article we discuss and analyse changes in the sex-age structure of both the urban and the rural population of the Republic of Kazakhstan since independence (1991) and until 2013. Spatial analysis by age and sex was carried out for the urban and rural population of the Republic of Kazakhstan. The article focuses on the population of Astana and Almaty as cities of “republican subordination”. The aim of this article is to study and analyse the sex-age structure of the total population taking the urban and rural population from 1991 to 2013 separately. For comparison and analysis of statistical data in the dynamics, the data by sex and age of the urban and rural population for 1991, 2001 and 2011 were examined. Thus changes over 10 years are considered. The age groups for which the data were collected were based on differentiation of the population by economic status: pre-working (0-14 years), working (15-64), and post-working age (over 65 years).

Management of Haemophilia in Sweden

1976 ◽  
Vol 35 (03) ◽  
pp. 510-521 ◽  
Author(s):  
Inga Marie Nilsson
Keyword(s):  
Factor Viii ◽  
Total Population ◽  
Age Groups ◽  
Factor Ix ◽  
Haemophilia A ◽  
Severe Haemophilia ◽  
Haemophilia B ◽  
Human Fraction ◽  
Mild Haemophilia

SummaryThe incidence of living haemophiliacs in Sweden (total population 8.1 millions) is about 1:15,000 males and about 1:30,000 of the entire population. The number of haemophiliacs born in Sweden in 5-year periods between 1931-1975 (June) has remained almost unchanged. The total number of haemophilia families in Sweden is 284 (77% haemophilia A, 23% haemophilia B) with altogether 557 (436 with A and 121 with B) living haemophiliacs. Of the haemophilia A patients 40 % have severe, 18 % moderate, and 42 % mild, haemophilia. The distribution of the haemophilia B patients is about the same. Inhibitors have been demonstrated in 8% of the patients with severe haemophilia A and in 10% of those with severe haemophilia B.There are 2 main Haemophilia Centres (Stockholm, Malmo) to which haemophiliacs from the whole of Sweden are admitted for diagnosis, follow-up and treatment for severe bleedings, joint defects and surgery. Minor bleedings are treated at local hospitals in cooperation with the Haemophilia Centres. The concentrates available for treatment in haemophilia A are human fraction 1-0 (AHF-Kabi), cryoprecipitate, Antihaemophilic Factor (Hyland 4) and Kryobulin (Immuno, Wien). AHF-Kabi is the most commonly used preparation. The concentrates available for treatment in haemophilia B are Preconativ (Kabi) and Prothromplex (Immuno). Sufficient amounts of concentrates are available. In Sweden 3.2 million units of factor VIII and 1.0 million units of factor IX are given per year. Treatment is free of charge.Only 5 patients receive domiciliary treatment, but since 1958 we in Sweden have practised prophylactic treatment of boys (4–18 years old) with severe haemophilia A. At about 5-10 days interval they receive AHF in amounts sufficient to raise the AHF level to 40–50%. This regimen has reduced severe haemophilia to moderate. The joint score is identical with that found in moderate haemophilia in the same age groups. For treatment of patients with haemophilia A and haemophilia B complicated by inhibitors we have used a large dose of antigen (factor VIII or factor IX) combined with cyclophosphamide. In most cases this treatment produced satisfactory haemostasis for 5 to 30 days and prevented the secondary antibody rise.

Aging of rural population in Yugoslavia

Stanovnistvo ◽  
1999 ◽  
Vol 37 (1-4) ◽  
pp. 73-92
Author(s):  
Jelena Antonovic
Keyword(s):  
Age Structure ◽  
Rural Population ◽  
Urban Areas ◽  
Age Groups ◽  
Population Ageing ◽  
Low Fertility ◽  
Demographic Ageing ◽  
Substantial Impact ◽  
Mass Migration ◽  
Rural And Urban

Mass migration to urban areas constitutes the basic direct factor of the decline in rural population of Yugoslavia in the second half of the 20th century. Due to the characteristic migration patterns by age and sex, they have had a substantial impact on the change in age structure of rural population towards rapid demographic ageing. By inducing decline in fertility and an increase in mortality, the newly formed age structure is increasingly becoming one of the basic factors to further decline in population, or even the major factor to rural depopulation in the majority of regions. The paper analyzes changes in age structure of rural population in the FR of Yugoslavia and across its republics and provinces during the period from 1961 to 1991. The conditions prevailing during the last census (1991) are particularly highlighted. The author points to distinct differences in ageing of urban versus rural populations, and considerable regional differences at the achieved level of demographic age. Based on the main demographic age indicators (the share of five-year and larger age groups, average age, ageing index and movement in major age-specific contingents), the author concludes that the process of population ageing had taken place in both rural and urban populations, but was more intensive in villages (higher share of the aged, higher index of ageing and higher average age) during the period under review. The author points to distinct ageing of rural population in all republics and provinces. It was most prominent in central Serbia and Vojvodina, while being quite slow in Kosovo and Metohia and recorded mainly in between the last two censuses (1981-1991). Likewise, Kosovo and Metohia constitute the only major region of Yugoslavia in which rural population in 1991 is still demographically younger than the population in urban settlements. Rural versus urban population ageing was much more intensive in other major regions of the country, both from the base and from the apex of the age pyramid. In view of the minimal differences in fertility and mortality levels by type of settlement (particularly in central Serbia and Vojvodina), the author argues that the inherited age structure constitutes the main cause of rapid acceleration in rural population ageing in low fertility regions.

scholarly journals Polarized nature of the COVID-19 pandemic in Japan: associations with population age structure and behaviours

2021 ◽  
Vol 49 (1) ◽  
Author(s):  
Junko Okumura
Keyword(s):  
Age Structure ◽  
Public Transportation ◽  
Perceived Risk ◽  
Online Survey ◽  
Preventive Measures ◽  
Age Groups ◽  
Cumulative Number ◽  
Population Age Structure ◽  
Major Factors ◽  
Drinking Places

Abstract Background Although the scale of the coronavirus disease (COVID-19) pandemic was relatively small in Japan compared with the rest of the world, the polarisation of areas into high- and low-COVID-19-incidence areas was observed among the 47 prefectures. The aims of this study were not only identifying the factors associated with the polarised COVID-19 pandemic in Japan but also discussing effective preventive measures. Methods This was an ecological study using online survey data which was cross-sectionally conducted by the author. A total of 6000 respondents who resided in 10 low- and 10 high-COVID-19 incidence prefectures, with a wide gap in terms of COVID-19 incidence, in Japan were recruited. Data on COVID-19 cases and geodemographic information were obtained from official government sites. Statistical analyses were conducted to compare variables between the two areas and age groups. Results This study revealed that that age influenced people’s behaviours and perceptions, except one behaviour of ‘wearing facemasks’. The major factors significantly associated with the cumulative number of COVID-19 cases per 100,000 people were ‘commuting by private automobile’ (adjusted odds ratio [AOR], 0.444; 95% confidence interval [CI], 0.394–0.501), ‘commuting by public transportation’ (AOR, 6.813; 95% CI, 5.567–8.336), ‘washing hands’ (AOR, 1.233; 95% CI, 1.005–1.511), ‘opening windows regularly’ (AOR, 1.248; 95% CI, 1.104–1.412), ‘avoiding crowded places (AOR, 0.757; 95% CI, 0.641–0.893), ‘non-scheduled visits to drinking places’ (AOR, 1.212; 95% CI, 1.054–1.392) and ‘perceived risk of contracting COVID-19’ (AOR, 1.380; 95% CI, 1.180–1.612). These factors were strongly associated with age groups. Conclusions Effective preventive measures for COVID-19 transmission can be developed by understanding the characteristics of populated areas, such as public transportation infrastructure and younger people’s movements and behaviours in relation to the population age structure to contain the current epidemic and protect the most vulnerable elderly people.

scholarly journals Comparison of Prevalence of Periodontitis with Different Indices in Population of District Ghaziabad

2016 ◽  
Vol 04 (01) ◽  
pp. 023-030
Author(s):  
Vimal Kumar ◽  
Pallak Arora ◽  
Manish Khatri ◽  
Shivani Sharma ◽  
Sumit Malhotra ◽  
...  
Keyword(s):  
Periodontal Disease ◽  
Total Population ◽  
Age Groups ◽  
Cross Sectional Study ◽  
Sample Population ◽  
Age Group ◽  
Cross Sectional ◽  
Multi Stage ◽  
Younger Age ◽  
Study Population

Abstract Objective: To estimate the prevalence of periodontal disease with different indices. Methods & materials: The study population consisted of multistage stratified random sample of 1300 subjects from total population of district Ghaziabad. A cross-sectional study was conducted with multi stage stratified random sampling techniques to select the sample population. The subjects were divided into different age groups and the periodontal assessment was made on the basis of CPITN index and ESI Index. Results: The CPITN has shown to estimate incorrect periodontal disease prevalence because of its underestimation of the disease severity. A huge difference was noticed in the prevalence rate of periodontitis when subjects were examined with ESI index. Conclusion Periodontal disease was found to be highly prevalent in the study population and severity of disease increased with age. More number of subjects in younger age group were found to be healthy.

Factor Structure of Shortened Children's Embedded Figures Test for Different Age Groups

1986 ◽  
Vol 63 (2) ◽  
pp. 479-486 ◽  
Author(s):  
Robert C. Hardy ◽  
John Eliot ◽  
Kenneth Burlingame
Keyword(s):  
Factor Analysis ◽  
Factor Structure ◽  
Total Population ◽  
Age Groups ◽  
Total Sample ◽  
Factor Loadings ◽  
Embedded Figures Test ◽  
Embedded Figures

240 children, 24 of each sex in Grades K to 4, were administered the entire Children's Embedded Figures Test, regardless of the failure rule. Factor loadings for items from a shortened version of the test were examined for a randomly divided sample, a sample divided by sex, a sample divided in two grade groupings, and an undivided total population. Stable factors were found for the total sample and when the sample was divided by sex. Analysis indicated that the factor analysis of the shortened form was consistent with previous analyses using the total scale.

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