demographic fluctuations
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Risks ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 66
Author(s):  
József Banyár

The broadly used pay-as-you-go (PAYG) pension system is intrinsically wrong. The essence of the problem is that the PAYG system distributes the yield of raising children, i.e., of human capital investment (which is essentially the pension contribution), in such a way that it disregards the extent to which individuals have contributed to this, and even whether it has occurred at all. This error can be corrected if we take the pension contribution to be the yield on an investment of human capital, and as such use this to pay back the costs and expenses of the raising of the contribution payer—overall to those who paid these costs and expenses at the time. Accordingly, the central question of my study is whether it is possible to construct a consistent pension system based on the above foundations, and how my ideas may be inserted into the Diamond–Samuelson model. The method of the study was logical analysis and the construction of a theoretical mathematical model. The results of the study show that it is possible to construct a public pension system that operates according to a different logic than today’s system, a system which is free from the effects of demographic fluctuations, which does not motivate the refusal to have children, and which will remain self-sufficient under all circumstances. The study achieves this by presenting a possible pension system of this kind in detail. Via the suitable modification of the Diamond–Samuelson model, I have succeeded in showing that the pension system I am proposing increases the willingness to have children up to the social optimum, in contrast to the fully (but traditionally) funded and PAYG systems. This system currently only exists in theory and may be regarded as a major theoretical innovation, which naturally has certain (although not particularly extensive) antecedents. Its introduction could enable the resolution of the contradictions of existing pension systems and could also provide a solution to the as yet unsolved problem of the increasingly expensive regeneration of human capital, and as such, its potential practical implications are immeasurable.


Author(s):  
Olga Ubeeva

Throughout the XX century, the demographic policy of the Soviet State was aimed mostly at working-age population or labor resources, taking into account regional and territorial aspects. Demographic change of the early XXI century was the result of political events of the 1990s, when the concept of population policy was under the radar of the government. The socioeconomic cataclysms destabilized the employment structure of population, caused deterioration of living standards, which affected the demographic characteristics of the XXI century. The demographic policy crisis of the late XX century generated one of the crucial organizational issues faced by the northern regions. This article is dedicated to the main demographic trends in the northern regions of Buryatia, which were affected by the construction of the Baikal-Amur Mainline, since completion of the construction project until stabilization of socioeconomic situation in the country by the early 2010s. In the course of construction of the Baikal-Amur Mainline, Buryatia took the lead in terms of birth rate, and ranked last in mortality index per thousand people. This testified to relative density of young poplar and children in the age structure, as well as stable population reproduction with insignificant demographic fluctuations.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Yael Artzy-Randrup ◽  
Tamir Epstein ◽  
Joel S. Brown ◽  
Ricardo L. B. Costa ◽  
Brian J. Czerniecki ◽  
...  

AbstractDisseminated cancer cells (DCCs) are detected in the circulation and bone marrow of up to 40% of breast cancer (BC) patients with clinically localized disease. The formation of metastases is governed by eco-evolutionary interactions of DCCs with the tissue during the transition from microscopic populations to macroscopic disease. Here, we view BC adjuvant and neoadjuvant treatments in the context of small population extinction dynamics observed in the Anthropocene era. Specifically, the unique eco-evolutionary dynamics of small asexually reproducing cancer populations render them highly vulnerable to: (1) environmental and demographic fluctuations, (2) Allee effects, (3) genetic drift and (4) population fragmentation. Furthermore, these typically interact, producing self-reinforcing, destructive dynamics—termed the Extinction Vortex—eradicating the population even when none of the perturbations is individually capable of causing extinction. We propose that developing BC adjuvant and neoadjuvant protocols may exploit these dynamics to prevent recovery and proliferation of small cancer populations during and after treatment—termed “Eco-evolutionary rescue” in natural extinctions. We hypothesize more strategic application of currently available agents based on the extinction vulnerabilities of small populations could improve clinical outcomes.


Animals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 124
Author(s):  
Kyriakos G. Dimitriou ◽  
Evangelos G. Kotsonas ◽  
Dimitrios E. Bakaloudis ◽  
Christos G. Vlachos ◽  
Graham J. Holloway ◽  
...  

The Eurasian Black Vulture is a globally threatened raptor that in Southeast Europe only occurs in an isolated population in Greece. We examined the population viability for the species under demographic fluctuations and conservation scenarios. The current population showed no possibility of extinction for the next 100 years. However, simulated scenarios showed that the most important factor affecting the viability of the species was medium and high poisoning, leading to 94.8% and 100% probability of extinction, respectively. Furthermore, high reduction of supplementary feeding highlighted an 18.6% extinction possibility. Also, a high increase of wind farms in the area may result in 17.4% extinction possibility. Additionally, the non-establishment of the feeding station in 1987 in the study area would have resulted in an extinction risk of 7%. The species can be translocated to the Olympus National Park by releasing 80 juveniles over 10 years. The implementation of the conservation scenarios concerning the establishment of a supplementary feeding site network, and the reintroduction of the Eurasian Black Vulture in its historic range, along with the elimination of threats posed by poisoning, low food availability, and wind farms would increase the probability of the species persistence and allow the population to become a source for dispersal across Southeast Europe.


2020 ◽  
Vol 12 (2) ◽  
pp. 59-65
Author(s):  
ОLHA HOMON

On the basis of use of modern research methods, the requirements for designing new types of teaching and educational complexes “Kindergarten – Primary School” were determined. It was established that the form and methods of kindergarten education have a certain analogy with the education in the first grades of primary school, which is one of the factors of feasibility of blocking and cooperation of the senior kindergarten groups with the elementary grades of general education schools and the formation of teaching and educational complexes on this basis, which enables receptiveness to demographic fluctuations and, if necessary, change of the function of kindergarten to the function of primary school, and vice versa – the flexibility and multivariance of the teaching environment is one of main conceptual provisions in building of network and typology of educational facilities at the present stage, on the basis of which the structural elements of school network in massive restrained urban development are formed.


2020 ◽  
Author(s):  
Daniel Fallu ◽  
Tony Brown ◽  
Kevin Walsh ◽  
Sara Cucchiaro ◽  
Paolo Tarolli ◽  
...  

<p>Terraces and lynchets are not only ubiquitous worldwide and within Europe but can provide increasingly important Ecosystem Services (ESs), which may be able to mitigate aspects of climate change. They are also probably a major cause of non-linearity between climate and erosion rates in agricultural systems as noted from alluvial and colluvial studies. In this paper we review the theoretical background of terraces and lynchets, present a modified classification, and show how new techniques are transforming the study of these widespread and often ancient anthropogenic landforms. Indeed the problems of dating terraces and also the time-consuming nature and costly surveys has held back the archaeological study of terraces until now. The applicable suite of techniques available now includes the creation of Digital Terrain Models (DTMs) from Structure from Motion (SfM) photogrammetry, Airborne and Terrestrial Laser Scanning (ALS-TLS); the use of OSL and pOSL, pXRF, FTIR, phytoliths, calcium oxalates from plants and potentially sedaDNA. Examples will be drawn from a recently started ERC project (TerrACE; ERC-2017-ADG: 787790, 2018-2023; https://www.terrace.no/) which is working at over 10 sites in Europe ranging from Norway to Greece.</p><p>This paper explains the development of a new holistic approach to terrace archaeology driven by a modern conceptualisation of human-landscape relationships, and facilitated by new scientific developments. We explain the rationale for our choice of case study areas, for example, the range of bio-climatic zones. In addition, this multi-regional approach allows us to address contingent regional and local historical/socioeconomic processes; from demographic fluctuations to the development of specific forms of agricultural techniques. Examples of DTM creation, field analyses and selected results will be given from Martleburg in Belgium and sites in Italy. We will then move on to explain how this combination of a comprehensive suite of modern field and laboratory methods and an interpretive strategy informed by the environmental humanities will yield exciting and groundbreaking results.</p>


eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Florian M Gartner ◽  
Isabella R Graf ◽  
Patrick Wilke ◽  
Philipp M Geiger ◽  
Erwin Frey

A guiding principle in self-assembly is that, for high production yield, nucleation of structures must be significantly slower than their growth. However, details of the mechanism that impedes nucleation are broadly considered irrelevant. Here, we analyze self-assembly into finite-sized target structures employing mathematical modeling. We investigate two key scenarios to delay nucleation: (i) by introducing a slow activation step for the assembling constituents and, (ii) by decreasing the dimerization rate. These scenarios have widely different characteristics. While the dimerization scenario exhibits robust behavior, the activation scenario is highly sensitive to demographic fluctuations. These demographic fluctuations ultimately disfavor growth compared to nucleation and can suppress yield completely. The occurrence of this stochastic yield catastrophe does not depend on model details but is generic as soon as number fluctuations between constituents are taken into account. On a broader perspective, our results reveal that stochasticity is an important limiting factor for self-assembly and that the specific implementation of the nucleation process plays a significant role in determining the yield.


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