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We consider a Darwinian (evolutionary game theoretic) version of a standard susceptible-infectious SI model in which the resistance of the disease causing pathogen to a treatment that prevents death to infected individuals is subject to evolutionary adaptation. We determine the existence and stability of all equilibria, both disease-free and endemic, and use the results to determine conditions under which the treatment will succeed or fail. Of particular interest are conditions under which a successful treatment in the absence of resistance adaptation (i.e. one that leads to a stable disease-free equilibrium) will succeed or fail when pathogen resistance is adaptive. These conditions are determined by the relative breadths of treatment effectiveness and infection transmission rate distributions as functions of pathogen resistance.

Abstract Recognizing territories is essential to decide behavior of population either human or animals, and interaction between groups or individuals according to the territorial awareness is universal. Understanding various mechanisms which affect on such species behaviors can be possible by evolutionary games, and in particular, the rock–paper–scissors (RPS) game has been played a key role as a paradigmatic model to explore biodiversity from microbiota to societies. Among paramount mechanisms in systems of RPS, the role of intraspecific interaction has been recently noted in terms of promoting biodiversity. Since intraspecific interaction is defined by an invasive reaction between individuals in the same group, the interaction may be also sensitive to the territorial awareness. To explore how territorial awareness-based intraspecific interaction can affect species biodiversity, we endow species with the mechanism in the classic RPS game. By means of the Monte-Carlo method, we find the phenomenon that the presence of species’ territorial awareness has an impact on intraspecific interaction which ultimately affects species biodiversity. At the same time, we also find that territorial awareness can play a significant role to the average waiting time for extinction which is numerically elucidated by exploiting the quantity: interface width statistic. Unlike prior research that concentrated solely on the relationship between interaction frequency and species diversity, our results shed lights on the important role of territorial awareness in models of RPS, and they reveal fascinating evolutionary outcomes in structured populations that are a unique consequence of such awareness behavior.

This paper examines the influence of distance to biorefinery plants on agricultural land value. The research utilizes micro-level data on characteristics of parcels and the locations of ethanol facilities in Central Nebraska, USA. I employ a theoretical model and an empirical hedonic approach to determine the effect of proximity. To address potential endogeneity, the econometric model adopts an instrumental variable. Estimates from the model provide evidence that land values significantly decrease as the distance from a parcel to a biorefinery plant increases. The results also reveal a non-linearity pattern in the model, with land prices falling at a decreasing rate with distance from ethanol plants.

Abstract Evolutionary games of cyclic competitions have been extensively studied to gain insights into one of the most fundamental phenomena in nature: biodiversity that seems to be excluded by the principle of natural selection. The Rock-Paper-Scissors (RPS) game of three species and its extensions [e.g., the Rock-Paper-Scissors-Lizard-Spock (RPSLS) game] are paradigmatic models in this field. In all previous studies, the intrinsic symmetry associated with cyclic competitions imposes a limitation on the resulting coexistence states, leading to only selective types of such states. We investigate the effect of nonuniform intraspecific competitions on coexistence and find that a wider spectrum of coexistence states can emerge and persist. This surprising finding is substantiated using three classes of cyclic game models through stability analysis, Monte Carlo simulations and continuous spatiotemporal dynamical evolution from partial differential equations. Our finding indicates that intraspecific competitions or alternative symmetry-breaking mechanisms can promote biodiversity to a broader extent than previously thought.

This paper examines how proximity to an ethanol plant influences land-use and crop choice among producers. We estimated a Tobit model of crop choice within parcels located in Central Nebraska in a 2014 sample period in order to analyze changes in land-use and crop choice. We employed Geographic Information System (GIS) databases to access relevant data on crop choice and other land uses in the study area parcels, in addition to detailed information on the location and capacity of irrigation wells. We utilized an instrumental variable approach to account for the endogeneity of crop choice with ethanol refinery locations in the study area. Our regional model also took into account specific characteristics of the local processing markets for grains, including animal food manufacturers and livestock as well as ethanol plants. Our estimates revealed that ethanol plants alter land-use in several ways. We found that proximity to an ethanol plant increases the share of land allocated to corn cultivation up to a distance of 30 miles and that the portion of land parcels allocated to corn production falls with distance from an ethanol plant in a non-linear pattern. We also find that land allocation to grassland and pasture rises with distance from ethanol plants.

In this paper we introduce a discrete model of brucellosis happened in Korean livestock farms and numerically analyze its dynamical features. To do it, we consider parameters data supported by Livestock Cooperatives. To control brucellosis, we investigate the relationship among key parameters, as applications of our model. We hope that our model may be used to reduce brucellosis in Korean livestock farms. [ABSTRACT FROM AUTHOR]