Search results for "age structure"
showing 7 items of 17 documents
Demographic aspects of aging
2021
Population aging is occurring in almost all developed countries, albeit with differences in timing and intensity. This unprecedented phenomenon is evident not only in the change in the population age structure, but also in the impressive increase in the average length of life. After describing past, current, and future population trends, this contribution presents theories explaining the reasons for this long-term process that is completely reshaping the age structure of the population. It also describes the inequalities in aging (focusing in particular on the differences by gender, education, and cause of death), and introduces some measures of the individual health and economic consequenc…
Identifiability problem for recovering the mortality rate in an age-structured population dynamics model
2014
In this article is studied the identifiability of the age-dependent mortality rate of the Von Foerster–Mc Kendrick model, from the observation of a given age group of the population. In the case where there is no renewal for the population, translated by an additional homogeneous boundary condition to the Von Foerster equation, we give a necessary and sufficient condition on the initial density that ensures the mortality rate identifiability. In the inhomogeneous case, modelled by a non-local boundary condition, we make explicit a sufficient condition for the identifiability property, and give a condition for which the identifiability problem is ill-posed. We illustrate this latter case wit…
Analysis of ecological shifts in the two‐age structured population model with Allee effect and environmental noise
2020
We study noise-induced transformations in the two-age structured population model with the Allee effect and environmental fluctuations. In this bistable model, ecological shifts are associated mathematically with random transitions between basins of coexisting attractors. The following phenomena are revealed and studied: (i) noise-induced extinction, (ii) stochastic regeneration, and (iii) excitement of random mixed-mode oscillations. Constructive abilities of the analytical method of confidence domains are demonstrated in the parametric study of these phenomena.
Studying poverty over time: an analysis by gender and age in Europe
2013
This paper aims to communicate a new conceptualization of persistent poverty used to build the class of longitudinal poverty indices by Mendola et al.(2011), and to show how these indices could be helpful in analyzing the characteristics of persistence of poverty among generations. The indices are based upon the idea that the longer the sequence of consecutive high poverty gaps is, the worse the situation experienced. Moreover they introduce, via a parameter, the idea that the evaluation of the individual experiences of poverty must take into account the poverty mobility in the society. An empirical application on European Community Household Panel data compare the contributions of each gen…
A Multivariate Age-Structured Stochastic Model with Immunization Strategies to Describe Bronchiolitis Dynamics
2021
Bronchiolitis has a high morbidity in children under 2 years old. Respiratory syncytial virus (RSV) is the most common pathogen causing the disease. At present, there is only a costly humanized monoclonal RSV-specific antibody to prevent RSV. However, different immunization strategies are being developed. Hence, evaluation and comparison of their impact is important for policymakers. The analysis of the disease with a Bayesian stochastic compartmental model provided an improved and more natural description of its dynamics. However, the consideration of different age groups is still needed, since disease transmission greatly varies with age. In this work, we propose a multivariate age-struct…
Biomarker sources for Parkinson's disease: Time to shed tears?
2015
Abstract Parkinson's disease (PD) is the most frequent neurodegenerative movement disorder. In nearby future its importance will increase, especially due to changes in age structure. There are still substantial problems in terms of early diagnosis of the disease. In clinical practice, the diagnosis of PD is still based on the evaluation of clinical presentation and is supported by various ancillary tests with heterogeneous predictive value. In regard to diagnosis and disease monitoring, body fluid-based biomarkers have become an indispensable tool in today's medicine. In this Current Opinion we briefly address the present approaches to biomarker development for PD, including clinical trials…
Aspetti demografici
2019
Il VI Rapporto Migrazioni in Sicilia fotografa una situazione radicalmente mutata, non soltanto nella nostra isola, ma in tutto il paese e a livello sovranazionale. Se da un lato la rinnovata attenzione verso le problematiche legate ai cambiamenti climatici ha portato alla nascita di un processo dal basso che ha coinvolto milioni di giovani in tanti paesi, dall’altro l’adozione di misure estreme per bloccare i flussi migratori (sempre più, peraltro, causati nel mondo dagli stessi cambiamenti climatici), ha avviato in altrettanti paesi un processo inverso, che nega l’efficacia di un approccio globale, anzi, ne teme gli effetti.