***** To join INSNA, visit http://www.insna.org ***** Barry Wellman _______________________________________________________________________ S.D. Clark Professor of Sociology, FRSC NetLab Director Department of Sociology 725 Spadina Avenue, Room 388 University of Toronto Toronto Canada M5S 2J4 twitter:barrywellman http://www.chass.utoronto.ca/~wellman fax:+1-416-978-3963 Updating history: http://chass.utoronto.ca/oldnew/cybertimes.php _______________________________________________________________________ Cooperation through imitation and exclusion in networks , Journal of Economic Dynamics and Control abstract: We study the coevolution of networks and action choices in a Prisoners' Dilemma. Agents in our model learn about both action choices and choices of interaction partners (links) by imitating successful behavior of others. The resulting dynamics yields outcomes where both cooperators and defectors coexist under a wide range of parameters. Two scenarios can arise. Either there is full separation of defectors and cooperators, i.e. they are found in two different, disconnected components. Or there is marginalization of defectors, i.e. connected networks emerge with a center of cooperators and a periphery of defectors. *  Cooperation through imitation and exclusion in networks, Fosco C , Mengel F, December 2010, DOI: 10.1016/j.jedc.2010.12.002, Journal of Economic Dynamics and Control, in Press  http://dx.doi.org/10.1016/j.jedc.2010.12.002 _________________________________________________________________ 13.01. Models of coalition or alliance formation , Journal of Theoretical Biology Abstract: More than half a century has now elapsed since coalition or alliance formation theory (CAFT) was first developed. During that time, researchers have amassed a vast amount of detailed and high-quality data on coalitions or alliances among primates and other animals. But models have not kept pace, and more relevant theory is needed. In particular, even though CAFT is primarily an exercise in polyadic game theory, game theorists have devoted relatively little attention to questions that motivate field research, and much remains largely unexplored. The state of the art is both a challenge and an opportunity. In this review we describe a variety of game-theoretic and related modelling approaches that have much untapped potential to address the questions that field biologists ask. *  Models of coalition or alliance formation, Mesterton-Gibbons M , Gavrilets S , Gravner J , Akçay E, December 2010, DOI: 10.1016/j.jtbi.2010.12.031, Journal of Theoretical Biology, in Press * Contributed by  Segismundo  http://dx.doi.org/10.1016/j.jtbi.2010.12.031  http://segis.name --------------------------------- _ 18. New System for Analyzing Information on WikiLeaks, Social Media , ScienceDaily Excerpts: () has designed a system for exploring information on networks or graphs that can complement internet search engines and is of particular interest in areas related to social media, the internet, biomedicine, fraud detection, education and advanced bibliographic searches. () the technology can be used to extract information from WikiLeaks from two perspectives: one, to obtain generic indicators that provide information on whether the data network has the features of a social network and whether communities of data are created that can provide relevant information; and two, to use the documents hosted on the website to analyze how a topic evolves over time, (). *  New System for Analyzing Information on WikiLeaks, Social Media, 2011/01/04, ScienceDaily & Universitat Politcnica de Catalunya  http://www.sciencedaily.com/releases/2011/01/110103110152.htm _________________________________________________________________ 19.03. Introduction to Complexity and Complex Systems , CRC Press Summary: The boundaries between simple and complicated, and complicated and complex system designations are fuzzy and debatable, even using quantitative measures of complexity. However, if you are a biomedical engineer, a biologist, physiologist, economist, politician, stock market speculator, or politician, you have encountered complex systems. Furthermore, your success depends on your ability to successfully interact with and manage a variety of complex systems. In order not to be blindsided by unexpected results, we need a systematic, comprehensive way of analyzing, modeling, and simulating complex systems to predict non-anticipated outcomes. (...) *  Introduction to Complexity and Complex Systems, Robert B. Northrop, 2010/12/08, CRC Press _________________________________________________________________ 19.04. Chaos: The Science of Predictable Random Motion , Oxford University Press Summary: Based on only elementary mathematics, this engaging account of chaos theory bridges the gap between introductions for the layman and college-level texts. It develops the science of dynamics in terms of small time steps, describes the phenomenon of chaos through simple examples, and concludes with a close look at a homoclinic tangle, the mathematical monster at the heart of chaos. The presentation is enhanced by many figures, animations of chaotic motion (available on a companion CD), and biographical sketches of the pioneers of dynamics and chaos theory. (...) *  Chaos: The Science of Predictable Random Motion, Richard Kautz, 2010/12/30, Oxford University Press _________________________________________________________________ 19.05. Networks of the Brain , The MIT Press Summary: Over the last decade, the study of complex networks has expanded across diverse scientific fields. Increasingly, science is concerned with the structure, behavior, and evolution of complex systems ranging from cells to ecosystems. Modern network approaches are beginning to reveal fundamental principles of brain architecture and function, and in this book, Olaf Sporns describes how the integrative nature of brain function can be illuminated from a complex network perspective. Highlighting the many emerging points of contact between neuroscience and network science, the book serves to introduce network theory to neuroscientists and neuroscience to those working on theoretical network models. (...) *  Networks of the Brain, Olaf Sporns, 2011/11/30, The MIT Press _____________________________________________________________________ SOCNET is a service of INSNA, the professional association for social network researchers (http://www.insna.org). To unsubscribe, send an email message to [log in to unmask] containing the line UNSUBSCRIBE SOCNET in the body of the message.