scholarly journals On the Spatial Diffusion of Cooperation with Endogenous Matching Institutions

2018 ◽  
Author(s):  
Emanuela Migliaccio ◽  
Thierry Verdier
Keyword(s):  
Local Community ◽  
Low Cost ◽  
Cooperative Behavior ◽  
Local Population ◽  
Reaction Diffusion ◽  
Reaction Diffusion Equations ◽  
Assortative Matching ◽  
Endogenous Matching ◽  
Asymptotic Speed ◽  
Mathematical Techniques

This paper studies the spatial joint evolution of cooperative behavior and a partially assortative matching institution that protects cooperators. We consider cooperation as characterized by a cultural trait transmitted via an endogenous socialization mechanism a la Bisin and Verdier (2001) and we assume that such trait can diffuse randomly in space due to some spatial noise in the socialization mechanism. Using mathematical techniques from reaction-diffusion equations theory, we show that, under some conditions, an initially localized domain of preferences for cooperation can invade the whole population and characterize the asymptotic speed of diffusion. We consider first thecase with exogenous assortativeness, and then endogeneize the degree of social segmentation in matching, assuming that it is collectively set at each point of time and space by the local community. We show how relatively low cost segmenting institutions can appear in new places thanks to the spatial random diffusion of cooperation, helping a localized cultural cluster of cooperation to invade the whole population. The endogenous assortative matching institution follows a life cycle process : appearing, growing and then disappearing once a culture of cooperation is suffciently established in the local population.

scholarly journals On the Spatial Diffusion of Cooperation with Endogenous Matching Institutions

Games ◽  
2018 ◽  
Vol 9 (3) ◽  
pp. 58
Author(s):  
Emanuela Migliaccio ◽  
Thierry Verdier
Keyword(s):  
Local Community ◽  
Low Cost ◽  
Cooperative Behavior ◽  
Local Population ◽  
Reaction Diffusion ◽  
Reaction Diffusion Equations ◽  
Assortative Matching ◽  
Endogenous Matching ◽  
Asymptotic Speed ◽  
Mathematical Techniques

This paper studies the spatial joint evolution of cooperative behavior and a partially assortative matching institution that protects cooperators. We consider cooperation as characterized by a cultural trait transmitted via an endogenous socialization mechanism and we assume that such trait can diffuse randomly in space due to some spatial noise in the socialization mechanism. Using mathematical techniques from reaction-diffusion equations theory, we show that, under some conditions, an initially localized domain of preferences for cooperation can invade the whole population and characterize the asymptotic speed of diffusion. We consider first the case with exogenous assortativeness, and then endogeneize the degree of social segmentation in matching, assuming that it is collectively set at each point of time and space by the local community. We show how relatively low cost segmenting institutions can appear in new places thanks to the spatial random diffusion of cooperation, helping a localized cultural cluster of cooperation to invade the whole population. The endogenous assortative matching institution follows a life cycle process: appearing, growing and then disappearing once a culture of cooperation is sufficiently established in the local population.

scholarly journals Virus-host interactions shape viral dispersal giving rise to distinct classes of travelling waves in spatial expansions

2020 ◽  
Author(s):  
Michael Hunter ◽  
Tongfei Liu ◽  
Wolfram Möbius ◽  
Diana Fusco
Keyword(s):  
Cooperative Behavior ◽  
Test Organism ◽  
Host Density ◽  
Reaction Diffusion ◽  
Reaction Diffusion Equations ◽  
Effective Density ◽  
Density Dependent ◽  
Phage T7 ◽  
The Impact ◽  
Density Dependent Dispersal

Reaction-diffusion waves have long been used to describe the growth and spread of populations undergoing a spatial range expansion. Such waves are generally classed as either pulled, where the dynamics are driven by the very tip of the front and stochastic fluctuations are high, or pushed, where cooperation in growth or dispersal results in a bulk-driven wave in which fluctuations are suppressed. These concepts have been well studied experimentally in populations where the cooperation leads to a density-dependent growth rate. By contrast, relatively little is known about experimental populations that exhibit a density-dependent dispersal rate.Using bacteriophage T7 as a test organism, we present novel experimental measurements that demonstrate that the diffusion of phage T7, in a lawn of host E. coli, is hindered by steric interactions with host bacteria cells. The coupling between host density, phage dispersal and cell lysis caused by viral infection results in an effective density-dependent diffusion rate akin to cooperative behavior. Using a system of reaction-diffusion equations, we show that this effect can result in a transition from a pulled to pushed expansion. Moreover, we find that a second, independent density-dependent effect on phage dispersal spontaneously emerges as a result of the viral incubation period, during which phage is trapped inside the host unable to disperse. Our results indicate both that bacteriophage can be used as a controllable laboratory population to investigate the impact of density-dependent dispersal on evolution, and that the genetic diversity and adaptability of expanding viral populations could be much greater than is currently assumed.

A Court in Decline? Examining the Regality Court Records of Melrose, Roxburghshire, 1657–84

2020 ◽  
Vol 40 (1) ◽  
pp. 1-16
Author(s):  
Vivienne Dunstan
Keyword(s):  
Seventeenth Century ◽  
Local Community ◽  
Local Population ◽  
Local Area ◽  
Vital Role ◽  
Local Communities ◽  
Court Records ◽  
Seminal Work

McIntyre, in his seminal work on Scottish franchise courts, argues that these courts were in decline in this period, and of little relevance to their local population. 1 But was that really the case? This paper explores that question, using a particularly rich set of local court records. By analysing the functions and significance of one particular court it assesses the role of this one court within its local area, and considers whether it really was in decline at this time, or if it continued to perform a vital role in its local community. The period studied is the mid to late seventeenth century, a period of considerable upheaval in Scottish life, that has attracted considerable attention from scholars, though often less on the experiences of local communities and people.

On a Nonlinear System of Reaction-Diffusion Equations

2006 ◽  
Vol 11 (2) ◽  
pp. 115-121 ◽  
Author(s):  
G. A. Afrouzi ◽  
S. H. Rasouli
Keyword(s):  
Weak Solution ◽  
Dirichlet Boundary ◽  
Smooth Boundary ◽  
Reaction Diffusion ◽  
Reaction Diffusion Equations ◽  
Dirichlet Boundary Conditions ◽  
Nonlinear Elliptic System ◽  
Positive Parameter ◽  
Nonlinear Elliptic ◽  
Positive Weak Solution

The aim of this article is to study the existence of positive weak solution for a quasilinear reaction-diffusion system with Dirichlet boundary conditions,− div(|∇u1|p1−2∇u1) = λu1α11u2α12... unα1n,   x ∈ Ω,− div(|∇u2|p2−2∇u2) = λu1α21u2α22... unα2n,   x ∈ Ω, ... , − div(|∇un|pn−2∇un) = λu1αn1u2αn2... unαnn,   x ∈ Ω,ui = 0,   x ∈ ∂Ω,   i = 1, 2, ..., n,  where λ is a positive parameter, Ω is a bounded domain in RN (N > 1) with smooth boundary ∂Ω. In addition, we assume that 1 < pi < N for i = 1, 2, ..., n. For λ large by applying the method of sub-super solutions the existence of a large positive weak solution is established for the above nonlinear elliptic system.

Gypsy Population of Tatarstan: Attitude to Education and Health

2019 ◽  
Vol 9 (4) ◽  
pp. 188-192
Author(s):  
Tatyana Alekseevna Titova ◽  
Elena Valeryevna Frolova ◽  
Elena Gennadievna Gushchina ◽  
Anastasia Victorovna Fakhrutdinova
Keyword(s):  
Local Community ◽  
Local Population ◽  
Health Problems ◽  
Educational Process ◽  
Health Protection ◽  
Complex Study ◽  
Education And Health ◽  
The Republic

Abstract The studied problem significanceis caused by theneed of complex study of the groups which are in an nonnative environment environment. The purpose of the article is study of the of the Gipsy population that live in Zelenodolsk district of the Republic of Tatarstan to the systems and education healthcare. The leading approach to a research of this problem is a polyparadigmal methodology. The educational process is understood as an instrument of socialization of Roma children and health problems of representatives of their population. Special attention is paid to the circumstance that the questions of education of children is far from being priority one for the Gipsy population of the explored area. The understanding of health protection haw essential differences in comparison with local population. The conclusion is drawn that integration of Roma into local community depends on support of initiatives of locals and administration by most of representatives of a camp. Materials of the article can be useful to ethnologists, social and cultural anthropologists, political scientists and also representatives of the bodies/ committees and institutions supervising questions of interethnic and inter-religious interaction.

Restoring and Controlling the Water Pollution of Endangered River in Bangladesh: A Case Study in Pabna City

2020 ◽  
Vol 3 (2) ◽  
pp. 68-81
Author(s):  
Abu Sadath ◽  
Farhana Afroz ◽  
Hosne Ara ◽  
Abdulla-Al Kafy
Keyword(s):  
Water Pollution ◽  
Local Community ◽  
River Flow ◽  
Low Cost ◽  
Design Approach ◽  
Government Officials ◽  
Conservation Plan ◽  
Policy Measures ◽  
And Control ◽  
Riverfront Development

Rivers are the lifeline of Bangladesh economy and serve as the source of water supply, fisheries, irrigation for agriculture, low-cost transport, generate electricity and conserve biodiversity. The Ichamati River situated in Pabna, Bangladesh is also a blessing for the city. However, recently, due to the irregular and unplanned activities adjacent to the riverside, the life, flow and water quality of the river is in a vulnerable condition. This study aims to identify the present status of the Ichamati River and provide an effective design approach and policy measures in restoring the river flow and control water pollution. The data was collected from the questioner surveys, key informant interviews and focus group discussions. Results suggest that several factors such as the construction of an illegal settlement, unplanned waste dumping, disposal of fiscal sludge through sewerage connection, lack of awareness among people regarding the importance of river biodiversity and absence of riverfront development and conservation plan are responsible for water pollution, inconsistent water flow and damaging the life cycle of Ichamati river. The design approach and policy measures were developed based on the perceptions of local community people, experts and government officials. The suggested policy measures will help to restore the flow of the river and reduce the water pollution, and the design approach will ensure the economic benefit of the riverfront development in future.

scholarly journals Blow-up analyses in nonlocal reaction diffusion equations with time-dependent coefficients under Neumann boundary conditions

2020 ◽  
Vol 18 (1) ◽  
pp. 1552-1564
Author(s):  
Huimin Tian ◽  
Lingling Zhang
Keyword(s):  
Boundary Conditions ◽  
Blow Up ◽  
Sufficient Conditions ◽  
Neumann Boundary ◽  
Reaction Diffusion ◽  
Neumann Boundary Conditions ◽  
Reaction Diffusion Equations ◽  
Time Dependent ◽  
Diffusion Equations ◽  
Nonlocal Reaction

Abstract In this paper, the blow-up analyses in nonlocal reaction diffusion equations with time-dependent coefficients are investigated under Neumann boundary conditions. By constructing some suitable auxiliary functions and using differential inequality techniques, we show some sufficient conditions to ensure that the solution u ( x , t ) u(x,t) blows up at a finite time under appropriate measure sense. Furthermore, an upper and a lower bound on blow-up time are derived under some appropriate assumptions. At last, two examples are presented to illustrate the application of our main results.

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