This study explores the influence of migration costs and rewarding schemes on cooperation through the implementation of computational behavioral models in spatial public goods games. The former involves a cost for agents to migrate to a neighboring group, while the latter rewards them for remaining in the same group for multiple rounds. By analyzing these mechanisms separately and in combination, we unveil their effects on cooperative behavior.
View Article and Find Full Text PDFThe role of the skin-gut axis in atopic dermatitis (AD) remains a subject of debate, limiting non-pharmacological interventions such as probiotics and prebiotics. To improve understanding of their potential as a monotherapy for stable mild cases, we conducted a real-life, multicenter, retrospective observational study in Italy. We administered three selected bacteria ( BS01, LP14, and LR05) orally to patients with mild atopic dermatitis without a placebo control group, following up for 12 weeks.
View Article and Find Full Text PDFThe local optima network model has proved useful in the past in connection with combinatorial optimization problems. Here we examine its extension to the real continuous function domain. Through a sampling process, the model builds a weighted directed graph which captures the function's minima basin structure and its interconnection and which can be easily manipulated with the help of complex networks metrics.
View Article and Find Full Text PDFReputation plays a key role among the mechanisms supporting cooperation in our society. This is a well-known observation and, in fact, several studies have shown that reputation may substantially increase cooperation among subjects playing Prisoner's Dilemma games in the laboratory. Unfortunately, recent experiments indicate that when reputation can be faked cooperation can still be maintained at the expense of honest subjects who are deceived by the dishonest ones.
View Article and Find Full Text PDFThe study of complex networks, and in particular of social networks, has mostly concentrated on relational networks, abstracting the distance between nodes. Spatial networks are, however, extremely relevant in our daily lives, and a large body of research exists to show that the distances between nodes greatly influence the cost and probability of establishing and maintaining a link. A random geometric graph (RGG) is the main type of synthetic network model used to mimic the statistical properties and behavior of many social networks.
View Article and Find Full Text PDFThe aim of this study was to compare linguistic and narrative skills of monolingual and bilingual preschoolers and to estimate linguistic predictors of the macro-structural level of narratives. A battery of linguistic measures in Italian was administered to sixty-four Monolinguals and sixty-four Early Bilinguals; it included Vocabulary, Phonological Awareness, Morphosyntactic Comprehension, Phonological Memory, Letter Knowledge, and Story Sequencing tasks. The narratives produced in the Story Sequencing task were coded.
View Article and Find Full Text PDFBackground: The treatment of cutaneous advanced non-melanoma skin cancers (NMSC) and multiple cutaneous and subcutaneous melanoma metastases (Mm) represents a main therapeutic challenge. Electrochemotherapy (ECT) is an anticancer procedure that facilitates the penetration of cytotoxic drugs into cancer cells by means of the application of electrical pulses. The aim of our study was to evaluate efficacy and tolerability of ECT in the treatment of advanced NMSC and Mm.
View Article and Find Full Text PDFIn a networked society like ours, reputation is an indispensable tool to guide decisions about social or economic interactions with individuals otherwise unknown. Usually, information about prospective counterparts is incomplete, often being limited to an average success rate. Uncertainty on reputation is further increased by fraud, which is increasingly becoming a cause of concern.
View Article and Find Full Text PDFA pressing issue in biology and social sciences is to explain how cooperation emerges in a population of self-interested individuals. Theoretical models suggest that one such explanation may involve the possibility of changing one's neighborhood by removing and creating connections to others, but this hypothesis has problems when random motion is considered and lacks experimental support. To address this, we have carried out experiments on diluted grids with human subjects playing a Prisoner's Dilemma.
View Article and Find Full Text PDFA robust worldwide air-transportation network (WAN) is one that minimizes the number of stranded passengers under a sequence of airport closures. Building on top of this realistic example, here we address how spatial network robustness can profit from cooperation between local actors. We swap a series of links within a certain distance, a cooperation range, while following typical constraints of spatially embedded networks.
View Article and Find Full Text PDFBackground: No studies are available in the literature on the distribution of different melanoma features and risk factors in the Italian geographical areas.
Objective: To identify the differences in clinical-pathological features of melanoma, the distribution of risk factors and sun exposure in various Italian macro-areas.
Methods: Multicentric-observational study involving 1,472 melanoma cases (713 north, 345 centre, 414 south) from 26 referral centres belonging to the Italian Multidisciplinary Group for Melanoma.
People need to rely on cooperation with other individuals in many aspects of everyday life, such as teamwork and economic exchange in anonymous markets. We study whether and how the ability to make or break links in social networks fosters cooperate, paying particular attention to whether information on an individual's actions is freely available to potential partners. Studying the role of information is relevant as information on other people's actions is often not available for free: a recruiting firm may need to call a job candidate's references, a bank may need to find out about the credit history of a new client, etc.
View Article and Find Full Text PDFIn order to investigate the behaviour of athletes in choosing sports, we analyse data from part of the We-Sport database, a vertical social network that links athletes through sports. In particular, we explore connections between people sharing common sports and the role of age and gender by applying "network science" approaches and methods. The results show a disassortative tendency of athletes in choosing sports, a negative correlation between age and number of chosen sports and a positive correlation between age of connected athletes.
View Article and Find Full Text PDFCoordination among different options is key for a functioning and efficient society. However, often coordination failures arise, resulting in serious problems both at the individual and the societal level. An additional factor intervening in the coordination process is individual mobility, which takes place at all scales in our world, and whose effect on coordination is not well known.
View Article and Find Full Text PDFMobility is a general feature of human and animal populations living in physical space. In particular, it has been observed that often these movements are of the Lévy flight type. In this paper we study the effect of such power-law distributed displacements on the evolution of cooperation in simple games played on diluted two-dimensional grids.
View Article and Find Full Text PDFWe study cyclic evolutionary games in a spatial diluted grid environment in which agents strategically interact locally but can also opportunistically move to other positions within a given migration radius. We find that opportunistic migration can inverse the cyclic prevalence between the strategies when the frequency of random imitation is large enough compared to the payoff-driven imitation. At the transition the average size of the patterns diverges and this threatens diversity of strategies.
View Article and Find Full Text PDFThis work presents a systematic study of population games of the Prisoner's Dilemma, Hawk-Dove, and Stag Hunt types in two-dimensional Euclidean space under two-person, one-shot game-theoretic interactions, and in the presence of agent random mobility. The goal is to investigate whether cooperation can evolve and be stable when agents can move randomly in continuous space. When the agents all have the same constant velocity cooperation may evolve if the agents update their strategies imitating the most successful neighbor.
View Article and Find Full Text PDFPhys Rev E Stat Nonlin Soft Matter Phys
October 2013
We study evolutionary games in a spatial diluted grid environment in which agents strategically interact locally but can also opportunistically move to other positions within a given migration radius. Using the imitation of the best rule for strategy revision, it is shown that cooperation may evolve and be stable in the Prisoner's Dilemma game space for several migration distances but only for small game interaction radius while the Stag Hunt class of games become fully cooperative. We also show that only a few trials are needed for cooperation to evolve, i.
View Article and Find Full Text PDFThe boards of directors at large European companies overlap with each other to a sizable extent both within and across national borders. This could have important economic, political and management consequences. In this work we study in detail the topological structure of the networks that arise from this phenomenon.
View Article and Find Full Text PDFEffective coordination is key to many situations that affect the well-being of two or more humans. Social coordination can be studied in coordination games between individuals located on networks of contacts. We study the behavior of humans in the laboratory when they play the Stag Hunt game - a game that has a risky but socially efficient equilibrium and an inefficient but safe equilibrium.
View Article and Find Full Text PDFPhys Rev E Stat Nonlin Soft Matter Phys
December 2012
In this work we study the behavior of classical two-person, two-strategies evolutionary games on networks embedded in a Euclidean two-dimensional space with different kinds of degree distributions and topologies going from regular to random and to scale-free ones. Using several imitative microscopic dynamics, we study the evolution of global cooperation on the above network classes and find that specific topologies having a hierarchical structure and an inhomogeneous degree distribution, such as Apollonian and grid-based networks, are very conducive to cooperation. Spatial scale-free networks are still good for cooperation but to a lesser degree.
View Article and Find Full Text PDFPhys Rev E Stat Nonlin Soft Matter Phys
September 2012
Spatially embedded networks are important in several disciplines. The prototypical spatial network we assume is the Random Geometric Graph, of which many properties are known. Here we present new results for the two-point degree correlation function in terms of the clustering coefficient of the graphs for two-dimensional space in particular, with extensions to arbitrary finite dimensions.
View Article and Find Full Text PDFPhys Rev E Stat Nonlin Soft Matter Phys
January 2012
In this work we study the behavior of classical two-person, two-strategies evolutionary games on a class of weighted networks derived from Barabási-Albert and random scale-free unweighted graphs. Using customary imitative dynamics, our numerical simulation results show that the presence of link weights that are correlated in a particular manner with the degree of the link end points leads to unprecedented levels of cooperation in the whole games' phase space, well above those found for the corresponding unweighted complex networks. We provide intuitive explanations for this favorable behavior by transforming the weighted networks into unweighted ones with particular topological properties.
View Article and Find Full Text PDF