Eternal Sunshine of the Solar Panel

The social dynamics of residential solar panel use within a theoretical population are studied using a compartmental model. In this study we consider three solar power options commonly available to consumers: the community block, leasing, and buying. In particular we are interested in studying how social influence affects the dynamics within these compartments. As a result of this research a threshold value is determined, beyond which solar panels persist in the population. In addition, as is standard in this type of study, we perform equilibrium analysis, as well as uncertainty and sensitivity analyses on the threshold value. We also perform uncertainty analysis on the population levels of each compartment. The analysis shows that social influence plays an important role in the adoption of residential solar panels

Cliophysics: Socio-political Reliability Theory, Polity Duration and African Political (In)stabilities

Quantification of historical sociological processes have recently gained attention among theoreticians in the effort of providing a solid theoretical understanding of the behaviors and regularities present in sociopolitical dynamics. Here we present a reliability theory of polity processes with emphases on individual political dynamics of African countries. We found that the structural properties of polity failure rates successfully capture the risk of political vulnerability and instabilities in which 87.50%, 75%, 71.43%, and 0% of the countries with monotonically increasing, unimodal, U-shaped and monotonically decreasing polity failure rates, respectively, have high level of state fragility indices. The quasi-U-shape relationship between average polity duration and regime types corroborates historical precedents and explains the stability of the autocracies and democracies.Comment: 4 pages, 3 figures, 1 tabl

Homo-psychologicus: Reactionary behavioural aspects of epidemics

We formulate an in silico model of pathogen avoidance mechanism and investigate its impact on defensive behavioural measures (e.g., spontaneous social exclusions and distancing, crowd avoidance and voluntary vaccination adaptation). In particular, we use SIR(B)S (e.g., susceptible-infected-recovered with additional behavioural component) model to investigate the impact of homo-psychologicus aspects of epidemics. We focus on reactionary behavioural changes, which apply to both social distancing and voluntary vaccination participations. Our analyses reveal complex relationships between spontaneous and uncoordinated behavioural changes, the emergence of its contagion properties, and mitigation of infectious diseases. We find that the presence of effective behavioural changes can impede the persistence of disease. Furthermore, it was found that under perfect effective behavioural change, there are three regions in the response factor (e.g., imitation and/or reactionary) and behavioural scale factor (e.g., global/local) factors ρ–α behavioural space. Mainly, (1) disease is always endemic even in the presence of behavioural change, (2) behavioural-prevalence plasticity is observed and disease can sometimes be eradication, and (3) elimination of endemic disease under permanence of permanent behavioural change is achieved. These results suggest that preventive behavioural changes (e.g., non-pharmaceutical prophylactic measures, social distancing and exclusion, crowd avoidance) are influenced by individual differences in perception of risks and are a salient feature of epidemics. Additionally, these findings indicates that care needs to be taken when considering the effect of adaptive behavioural change in predicting the course of epidemics, and as well as the interpretation and development of the public health measures that account for spontaneous behavioural changes

Mathematical Analysis of an SIVRWS Model for Pertussis with Waning and Naturally Boosted Immunity

This work aims mainly to study the controllability of pertussis infection in the presence of waning and natural booster of pertussis immunity and to study their impact on the overall dynamics and disease outcomes. Therefore, an SIVRWS (Susceptible-Infected-Vaccinated-Recovered-Waned-Susceptible) model for pertussis infection spread in a demographically stationary, homogeneous, and fully symmetric mixing population is introduced. The model has been mathematically analyzed, where both equilibrium and stability analyses have been established, and uniform persistence of the model has been shown. The conditions on model parameters that ensure effective control of the infection have been derived. The effects of the interplay between waning and boosting pertussis immunity by re-exposure to Bordetella pertussis and vaccination on the dynamics have been investigated. The analytical results have been numerically confirmed and explained. The analysis reveals that ignoring the natural booster of immunity overestimates the endemic prevalence of the infection. Moreover, ignoring the differential susceptibility between secondary and primary susceptible individuals overestimates the critical vaccination coverage required to eliminate the infection. Moreover, the shorter the period of immunity acquired by either vaccination or experiencing natural infection, the higher the reproduction number and the endemic prevalence of infection, and therefore, the higher the effort needed to eliminate the infection

Mathematical Analysis of an SIVRWS Model for Pertussis with Waning and Naturally Boosted Immunity

This work aims mainly to study the controllability of pertussis infection in the presence of waning and natural booster of pertussis immunity and to study their impact on the overall dynamics and disease outcomes. Therefore, an SIVRWS (Susceptible-Infected-Vaccinated-Recovered-Waned-Susceptible) model for pertussis infection spread in a demographically stationary, homogeneous, and fully symmetric mixing population is introduced. The model has been mathematically analyzed, where both equilibrium and stability analyses have been established, and uniform persistence of the model has been shown. The conditions on model parameters that ensure effective control of the infection have been derived. The effects of the interplay between waning and boosting pertussis immunity by re-exposure to Bordetella pertussis and vaccination on the dynamics have been investigated. The analytical results have been numerically confirmed and explained. The analysis reveals that ignoring the natural booster of immunity overestimates the endemic prevalence of the infection. Moreover, ignoring the differential susceptibility between secondary and primary susceptible individuals overestimates the critical vaccination coverage required to eliminate the infection. Moreover, the shorter the period of immunity acquired by either vaccination or experiencing natural infection, the higher the reproduction number and the endemic prevalence of infection, and therefore, the higher the effort needed to eliminate the infection

Modelos de la propagación de enfermedades infecciosas

Modelo de Kermack y McKendrick. Modelos de compartimientos. Período de exposición no infeccioso. Tiempos de espera. Población total variable. Transmisión por vectores. Propagación del VIH. Estructura social. Sistema axiomático de apareamiento. SIDA con infectividad variable. Transmisión de la influenza. Introducción a los modelos probabilísticos. Modelos estocásticos en epidemiología. Modelos estocásticos para la dispersión espacial de especies. La dinámica de un virus dentro del huésped. La importancia de la pedagogía matemática en el modelaje matemático. BibliografiaLa preparación de este manuscrito es producto de la colaboración de múltiples generaciones de biólogos matemáticos. La historia del libro inicia en 1996 cuando Carlos Castillo-Chávez fundó el MTBI en la Universidad de Comell. Este programa de verano se realizó desde entonces en conjunto con diversas instituciones: la Universidad de Comell en los años 1996 - 2003, el laboratio nacional de los Alamos en el período 2003 - 2005, Y la Universidad Estatal de Arizona en los años 2004 - 2014. El objetivo del MTBI ha sido fomentar el desarrollo académico y científico de grupos minoritarios en los Estados Unidos y toda Latinoamérica. El presente libro ha sido escrito con el objetivo de motivar a los jóvenes matemáticos y biólogos latinoamericanos interesados en encontrar soluciones a los retos originados por factores de tipo social y ambiental. Este día, en el marco del sexagésimo aniversario del Departamento de Matemáticas de la Universidad del Valle, gracias al esfuerzo de todas aquellas personas que han contribuido a fomentar el desarrollo de la matemática en Colombia, el profesor Carlos Castillo-Chávez ha elegido publicar este volumen de forma gratuita en la red, como tributo a este destacado proces

Stakeholder Salience Changes in an e-Government Implementation Project

In this article we discuss in what ways an e-government project can give both expected and unexpected effects for agency employees and their working tasks. The purpose of this article is to illustrate the fact that, besides the aim to increase agency efficiency and citizen benefit, e-government implementation might also change the salience of involved stakeholders. We do this by focusing on one stakeholder group which was reluctant and hesitating in the beginning of the studied project; marginalized, passive, easily convinced, and old-fashioned. After the e-government implementation, this group had turned to satisfied, proud, influential, active, powerful, and modern IT users. The case shows how stakeholder salience might change over time in an e-government project. Stakeholder influence aspects and IT driven change aspects are intertwined. This makes it necessary for any e-government project to address the notion of stakeholder involvement in decision-making during the development and implementation phases, but also to acknowledge e-services force to change how things and people are perceived during these phases