Complexity Digest 2011.24

2011/12/09

Editor-in-Chief: Carlos Gershenson
Founding Editor: Gottfried Mayer

Webcast Archive relaunched: comdig.unam.mx/webcasts/

For individual e-mail subscriptions go to Subscriptions.
Previous issue 2011.23 | Next issue 2011.25

Content

  1. Complex Systems: A Survey, arXiv
  2. Building a Science of Cities, CASA Working Papers
  3. What Are Leaders Really For?, HBR Blog Network
  4. An Experimental Study of Homophily in the Adoption of Health Behavior, Science
  5. Luis von Ahn: Massive-scale online collaboration, TED.com
    1. Cheryl Hayashi: The magnificence of spider silk, TED.com
  6. How to Fix World Transportation, BusinessWeek
    1. Complexity in human transportation networks: a comparative analysis of worldwide air transportation and global cargo-ship movements, Eur. Phys. J. B
  7. An Evolution Toward a Programmable Universe, NYTimes.com
  8. Impact of epistasis and pleiotropy on evolutionary adaptation, Proc. R. Soc. B
  9. Empathy and Pro-Social Behavior in Rats, Science
  10. Energetics and the evolution of human brain size, Nature
  11. How The "Internet Of Things" Is Turning Cities Into Living Organisms, Fast Company
  12. Dynamics of non-equilibrium communities, Proc. R. Soc. B
  13. The Dichotomy in Degree Correlation of Biological Networks, PLoS ONE
  14. Context Modularity of Human Altruism, Science
    1. Cooperation, structure and hierarchy in multiadaptive games, arXiv
  15. Philosophy: Meditation in mind, Nature
  16. Entangling Macroscopic Diamonds at Room Temperature, Science
  17. The structure of coevolving infection networks, arXiv
    1. Recurrent host mobility in spatial epidemics: beyond reaction-diffusion, Eur. Phys. J. B
  18. Guiding the self-organization of random Boolean networks, Theory in Biosciences
  19. Book Announcements
    1. Evolution and the Emergent Self: The Rise of Complexity and Behavioral Versatility in Nature, Columbia University Press
    2. The Number That Killed Us: A Story of Modern Banking, Flawed Mathematics, and a Big Financial Crisis, Wiley
    3. The Common Extremalities in Biology and Physics, Second Edition: Maximum Energy Dissipation Principle in Chemistry, Biology, Physics and Evolution, Elsevier
    4. Where the Conflict Really Lies: Science, Religion, and Naturalism, Oxford University Press
  20. Links & Snippets
    1. Other Publications
    2. Event Announcements
    3. Video Announcements
    4. Other Announcements

  1. Complex Systems: A Survey, arXiv Next Article Bookmark and Share

    Abstract: A complex system is a system composed of many interacting parts, often called agents, which displays collective behavior that does not follow trivially from the behaviors of the individual parts. Examples include condensed matter systems, ecosystems, stock markets and economies, biological evolution, and indeed the whole of human society. Substantial progress has been made in the quantitative understanding of complex systems, particularly since the 1980s, using a combination of basic theory, much of it derived from physics, and computer simulation. The subject is a broad one, drawing on techniques and ideas from a wide range of areas. Here I give a survey of the main themes and methods of complex systems science and an annotated bibliography of resources, ranging from classic papers to recent books and reviews.

  2. Building a Science of Cities, CASA Working Papers Next Article Bookmark and Share

    Excerpt: Our understanding of cities is being transformed by new approaches from the complexity sciences (Batty, 2005). Here we review progress, sketching the background beginning with the systems approach which treated systems as being organised from the top down to that which now dominates where systems are treated as evolving from the bottom up. The switch in thinking we describe is best pictured in the transition from thinking of 'cities as machines' to 'cities as organisms'. (…)

  3. What Are Leaders Really For?, HBR Blog Network Next Article Bookmark and Share

    Excerpt: By refusing to name a leader, Occupy Wall Street presents a challenge to this view. With no one figure to credit or blame, with no face to put on a sprawling inchoate movement, and with no hierarchy of power, we simply don't know how to process what "it" is, and therefore how to think about it. And because this absence of a familiar personality-centric narrative makes us uncomfortable, we are tempted to reject the whole thing as somehow not real. Or instead, we insist that in order to be taken seriously, the movement must first change to reflect what we expect from serious organizations â€" namely a charismatic leader to whom we can attribute everything.

  4. An Experimental Study of Homophily in the Adoption of Health Behavior, Science Next Article Bookmark and Share

    Abstract: How does the composition of a population affect the adoption of health behaviors and innovations? Homophilyâ€"similarity of social contactsâ€"can increase dyadic-level influence, but it can also force less healthy individuals to interact primarily with one another, thereby excluding them from interactions with healthier, more influential, early adopters. As a result, an important network-level effect of homophily is that the people who are most in need of a health innovation may be among the least likely to adopt it. Despite the importance of this thesis, confounding factors in observational data have made it difficult to test empirically. We report results from a controlled experimental study on the spread of a health innovation through fixed social networks in which the level of homophily was independently varied. We found that homophily significantly increased overall adoption of a new health behavior, especially among those most in need of it.

  5. Luis von Ahn: Massive-scale online collaboration, TED.com Next Article Bookmark and Share

    About this talk: After re-purposing CAPTCHA so each human-typed response helps digitize books, Luis von Ahn wondered how else to use small contributions by many on the Internet for greater good. At TEDxCMU, he shares how his ambitious new project, Duolingo, will help millions learn a new language while translating the Web quickly and accurately -- all for free.

    1. Cheryl Hayashi: The magnificence of spider silk, TED.com Next Article Bookmark and Share

      About this talk: Cheryl Hayashi studies spider silk, one of nature's most high-performance materials. Each species of spider can make up to 7 very different kinds of silk. How do they do it? Hayashi explains at the DNA level -- then shows us how this super-strong, super-flexible material can inspire.

  6. How to Fix World Transportation, BusinessWeek Next Article Bookmark and Share

    Excerpt: Keeping people and goods moving safely and efficientlyâ€"whether by land, sea, or airâ€"is one of the great challenges of the modern age. Complications include aging infrastructure, sprawling cities, shrinking budgets, and the predictable unpredictability of human behavior. To find out how to fix transportation for the 21st century (…) Norman Pearlstine gathered an all-star cast: [Dale Moser, Michael Replogle, Christopher Lee, Dennis Archer, Balaji Prabhakar, and O.P. Agarwal ] (…)

    1. Complexity in human transportation networks: a comparative analysis of worldwide air transportation and global cargo-ship movements, Eur. Phys. J. B Next Article Bookmark and Share

      Excerpt: We present a comparative network-theoretic analysis of the two largest global transportation networks: the worldwide air-transportation network (WAN) and the global cargo-ship network (GCSN). We show that both networks exhibit surprising statistical similarities despite significant differences in topology and connectivity. Both networks exhibit a discontinuity in node and link betweenness distributions which implies that these networks naturally segregate into two different classes of nodes and links.

  7. An Evolution Toward a Programmable Universe, NYTimes.com Next Article Bookmark and Share

    Excerpt: Such computational power, co-located with the gigantic storage that holds the data from all the incoming data streams, will enable faster-than-real-time simulations of many aspects of our physical world. As Mike Liebhold and his colleagues at the Institute for the Future have discussed, computing will have evolved from merely sensing local information to analyzing it to being able to control it. In this evolution, the world gradually becomes programmable.

  8. Impact of epistasis and pleiotropy on evolutionary adaptation, Proc. R. Soc. B Next Article Bookmark and Share

    Excerpt: Evolutionary adaptation is often likened to climbing a hill or peak. While this process is simple for fitness landscapes where mutations are independent, the interaction between mutations (epistasis) as well as mutations at loci that affect more than one trait (pleiotropy) are crucial in complex and realistic fitness landscapes.

  9. Empathy and Pro-Social Behavior in Rats, Science Next Article Bookmark and Share

    Abstract: Whereas human pro-social behavior is often driven by empathic concern for another, it is unclear whether nonprimate mammals experience a similar motivational state. To test for empathically motivated pro-social behavior in rodents, we placed a free rat in an arena with a cagemate trapped in a restrainer. After several sessions, the free rat learned to intentionally and quickly open the restrainer and free the cagemate. Rats did not open empty or object-containing restrainers. They freed cagemates even when social contact was prevented. When liberating a cagemate was pitted against chocolate contained within a second restrainer, rats opened both restrainers and typically shared the chocolate. Thus, rats behave pro-socially in response to a conspecific’s distress, providing strong evidence for biological roots of empathically motivated helping behavior.

  10. Energetics and the evolution of human brain size, Nature Next Article Bookmark and Share

    Excerpt: The human brain stands out among mammals by being unusually large. The expensive-tissue hypothesis1 explains its evolution by proposing a trade-off between the size of the brain and that of the digestive tract, which is smaller than expected for a primate of our body size. Although this hypothesis is widely accepted, empirical support so far has been equivocal. Here we test it in a sample of 100 mammalian species, including 23 primates, by analysing brain size and organ mass data. We found that, controlling for fat-free body mass, brain size is not negatively correlated with the mass of the digestive tract or any other expensive organ, thus refuting the expensive-tissue hypothesis.

  11. How The "Internet Of Things" Is Turning Cities Into Living Organisms, Fast Company Next Article Bookmark and Share

    Excerpt: When city services can autonomously go online and digest information from the cloud, they can reach a level of performance never before seen. First up, water systems that automatically know when it will rain and react accordingly.

  12. Dynamics of non-equilibrium communities, Proc. R. Soc. B Next Article Bookmark and Share

    Excerpt: Much effort in theoretical ecology has focused on identifying mechanisms that promote stable coexistence of species at equilibrium. However, in a consumer-resource model of competition along an environmental gradient, high-diversity assemblages have the potential to persist in non-equilibrium states for millions of generations with very little species loss.

  13. The Dichotomy in Degree Correlation of Biological Networks, PLoS ONE Next Article Bookmark and Share

    Excerpt: Most complex networks from different areas such as biology, sociology or technology, show a correlation on node degree where the possibility of a link between two nodes depends on their connectivity. It is widely believed that complex networks are either disassortative (links between hubs are systematically suppressed) or assortative (links between hubs are enhanced). In this paper, we analyze a variety of biological networks and find that they generally show a dichotomous degree correlation.

  14. Context Modularity of Human Altruism, Science Next Article Bookmark and Share

    Abstract: Whereas altruism drives the evolution of human cooperation, ethno-religious diversity has been considered to obstruct it, leading to poverty, corruption, and war. We argue that current research has failed to properly account for the institutional environment and how it affects the role diversity plays. The emergence of thriving, diverse communities throughout human history suggests that diversity does not always lead to cooperation breakdown. We conducted experiments in Mostar, Bosnia-Herzegovina with Catholic Croats and Muslim Bosniaks at a critical historic moment in the city’s postwar history. Using a public goods game, we found that the ability to sanction is key to achieving cooperation in ethno-religiously diverse groups, but that sanctions succeed only in integrated institutional environments and fail in segregated ones. Hence, we show experimentally for the first time in a real-life setting that institutions of integration can unleash human altruism and restore cooperation in the presence of diversity.

    1. Cooperation, structure and hierarchy in multiadaptive games, arXiv Next Article Bookmark and Share

      Excerpt: Game-theoretical models where the rules of the game and the interaction structure both coevolves with the game dynamics -- multiadaptive games -- capture very flexible situations where cooperation among selfish agents can emerge. In this work, we will discuss a multiadaptive model presented in a recent Letter [Phys. Rev. Lett. 106, 028702 (2011)], and generalizations of it. The model captures a non-equilibrium situation where social unrest increases the incentive to cooperate and, simultaneously, agents are partly free to influence with whom they interact. (…)

  15. Philosophy: Meditation in mind, Nature Next Article Bookmark and Share

    Excerpt: Buddhism is a distinctive world religion. It lacks an 'omnigod' â€" an omnipresent, omniscient, all-powerful creator â€" and a notion of humans as complexes of physical bodies and souls that ascend to heaven after death. Could it be mingled with the scientific culture of the twenty-first century to produce a new philosophical outlook on the world, the mind and our values? That idea lies at the heart of these two contrasting books on Buddhism and science.

  16. Entangling Macroscopic Diamonds at Room Temperature, Science Next Article Bookmark and Share

    Abstract: Quantum entanglement in the motion of macroscopic solid bodies has implications both for quantum technologies and foundational studies of the boundary between the quantum and classical worlds. Entanglement is usually fragile in room-temperature solids, owing to strong interactions both internally and with the noisy environment. We generated motional entanglement between vibrational states of two spatially separated, millimeter-sized diamonds at room temperature. By measuring strong nonclassical correlations between Raman-scattered photons, we showed that the quantum state of the diamonds has positive concurrence with 98% probability. Our results show that entanglement can persist in the classical context of moving macroscopic solids in ambient conditions.

  17. The structure of coevolving infection networks, arXiv Next Article Bookmark and Share

    Abstract: Disease awareness in infection dynamics can be modeled with adaptive contact networks whose rewiring rules reflect the attempt by susceptibles to avoid infectious contacts. Simulations of this type of models show an active phase with constant infected node density in which the interplay of disease dynamics and link rewiring prompts the convergence towards a well defined degree distribution, irrespective of the initial network topology. We develop a method to study this dynamic equilibrium and give an analytic description of the structure of the characteristic degree distributions and other network measures. The method applies to a broad class of systems and can be used to determine the steady-state topology of many other adaptive networks.

    1. Recurrent host mobility in spatial epidemics: beyond reaction-diffusion, Eur. Phys. J. B Next Article Bookmark and Share

      Excerpt: Human mobility is a key factor in spatial disease dynamics and related phenomena. In computational models host mobility is typically modeled by diffusion in space or on metapolulation networks. Alternatively, an effective force of infection across distance has been introduced to capture spatial dispersal implicitly. Both approaches do not account for important aspects of natural human mobility, diffusion does not capture the high degree of predictability in natural human mobility patters, e.g. the high percentage of return movements to individuals’ base location, the effective force of infection approach assumes immediate equilibrium with respect to dispersal. These conditions are typically not met in natural scenarios. We investigate an epidemiological model that explicitly captures natural individual mobility patterns.

  18. Guiding the self-organization of random Boolean networks, Theory in Biosciences Next Article Bookmark and Share

    Abstract: Random Boolean networks (RBNs) are models of genetic regulatory networks. It is useful to describe RBNs as self-organizing systems to study how changes in the nodes and connections affect the global network dynamics. This article reviews eight different methods for guiding the self-organization of RBNs. In particular, the article is focused on guiding RBNs toward the critical dynamical regime, which is near the phase transition between the ordered and dynamical phases. The properties and advantages of the critical regime for life, computation, adaptability, evolvability, and robustness are reviewed. The guidance methods of RBNs can be used for engineering systems with the features of the critical regime, as well as for studying how natural selection evolved living systems, which are also critical.

  19. Book Announcements Next Article Bookmark and Share

    1. Evolution and the Emergent Self: The Rise of Complexity and Behavioral Versatility in Nature, Columbia University Press Next Article Bookmark and Share

      Summary:
      How did humans emerge from the cosmos and the pre-biotic Earth, and what mechanisms of biological, chemical, and physical sciences drove this increasingly complex process? Neubauer presents a view of nature that describes the rising complexity of life in terms of increasing information content, first in genes and then in brains. The evolution of the nervous system expanded the capacity of organisms to store information, making learning possible. The author portrays four species with high brain-body ratios-chimpanzees, elephants, ravens, and dolphins-showing how each species shares with humans the capacity for complex communication, elaborate social relationships, flexible behavior (...).

    2. The Number That Killed Us: A Story of Modern Banking, Flawed Mathematics, and a Big Financial Crisis, Wiley Next Article Bookmark and Share

      Summary:
      The devastating financial crisis that began in the summer of 2007 and led to staggering losses for the banking industry, a global economic recession, and an implosion in government finances was caused by two main factors: toxic assets and leverage. But why did banks and other financial institutions take on this "toxic leverage" in the first place? Because an immensely powerful, but little talked about, mathematical model told them to. Known as Value at Risk (VaR), this model inaccurately projected no risk for these clearly worthless assets, insisting that they could be accumulated worry-free. (...)

    3. The Common Extremalities in Biology and Physics, Second Edition: Maximum Energy Dissipation Principle in Chemistry, Biology, Physics and Evolution, Elsevier Next Article Bookmark and Share

      Summary:
      This book is the first unified systemic description of dissipative phenomena, taking place in biology, and non-dissipative (conservative) phenomena which is more relevant to physics. Fully updated and revised, this new edition extends our understanding of nonlinear phenomena in biology and physics from the extreme / optimal perspective.

    4. Where the Conflict Really Lies: Science, Religion, and Naturalism, Oxford University Press Next Article Bookmark and Share

      Summary:
      This book is a long-awaited major statement by a pre-eminent analytic philosopher, Alvin Plantinga, on one of our biggest debates -- the compatibility of science and religion. Plantinga examines where this conflict is supposed to exist - evolution, evolutionary psychology, analysis of scripture, scientific study of religion - as well as claims by Dan Dennett, Richard Dawkins, and Philip Kitcher that evolution and theistic belief cannot co-exist. Plantinga makes a case that their arguments are not only inconclusive but that the supposed conflicts themselves are superficial, due to the methodological naturalism used by science. (...)

  20. Links & Snippets Next Article Bookmark and Share

    1. Other Publications Next Article Bookmark and Share

      1. Control and Synchronization of Neuron Ensembles, Jr-Shin Li, Isuru Dasanayake, and Justin Ruths, 2011/11/27, arXiv:1111.6306
      2. Modularity, Noise and natural selection, Gabriel Marroig, Diogo Melo, Guilherme Garcia, 2011/12/6, arXiv:1112.1391

    2. Event Announcements Next Article Bookmark and Share

      1. New England Complex Systems Institute Winter School, Cambridge, MA, USA, 2012/01/02-13
      2. 41th Winter Meeting on Statistical Physics, Xalapa, Veracruz, Mexico, 2012/01/3-6
      3. VI Congreso Bienal Internacional Complejidad 2012, Havana, Cuba, 2012/01/10-13
      4. 38th International Conference on Current Trends in Theory and Practice of Computer Science, Špindlerův Mlýn, Czech Republic, 2012/01/21-27
      5. 4th International Conference on Agents and Artificial Intelligence - ICAART 2012, Vilamoura, Algarve, Portugal, 2012/02/6-8
      6. WIVACE 2012 Italian Workshop on Artificial Life and Evolutionary Computation "Artificial Life, Evolution and Complexity" , Parma, Italy, 2012/02/20-21
      7. 3rd Workshop on Complex Networks, Melbourne, Florida, USA, 2012/03/7-9
      8. evostar - the main european events on evolutionary computation eurogp, evocop, evobio, evomusart and evoapplications, Málaga, Spain, 2012/03/11-13
      9. 9th International Conference on the Evolution of Language (Evolang IX), Kyoto, Japan, 2012/03/13-16
      10. IWSOS'12 (Sixth International Workshop on Self-Organizing Systems), Delft, The Netherlands, 2012/03/15-16
      11. 5th International Nonlinear Science Conference 2012, Barcelona, Spain, 2011/03/15-17
      12. IPCAT 2012: Ninth International Conference on Information Processing in Cells and Tissues, Cambridge, United Kingdom, 2012/03/31-04/02
      13. 21st European Meeting on Cybernetics and Systems Research, Vienna, Austria, 2012/04/10-13
      14. Collective Intelligence 2012, Cambridge, MA, USA, 2012/04/18-20
      15. 2012 IEEE World Congress on Computational Intelligence, Brisbane, Australia, 2012/06/10-15
      16. CiE 2012 Turing Centenary conference: How the World Computes, Cambridge, UK, 2012/06/18-23
      17. Cellular Automata Algorithms & Architectures (CAAA 2012), Madrid, Spain, 2012/07/2-6
      18. GECCO 2012, Philadelphia, USA, 2012/07/7-11
      19. 25th European Conference on Operational Research, Vilnius, Lithuania, 2012/07/8-11
      20. ALife XIII: The Thirteenth International Conference on the Simulation and Synthesis of Living Systems, Lansig, Michigan, USA, 2012/08/19-22
      21. 12th International Conference on Parallel Problem Solving From Nature (PPSN2012), Taormina, Italy, 2012/09/1-5
      22. ECCS'12: European Conference on Complex Systems, Brussels, Belgium, 2012/09/3-7
      23. Interdisciplinary Symposium on Complex Systems, Kos island, Greece, 2012/09/19-25
      24. 10th International Conference on Cellular Automata for Research and Industry (ACRI 2012), Santorini Island, Greece, 2012/09/24-27

    3. Video Announcements Next Article Bookmark and Share

      1. Complexity Digest videos.
      2. Lakeside Labs videos.
      3. FuturICT videos.
      4. Brain-Mind Institute webinars
      5. IFISC@uib.es seminars.
      6. ASSYST Digital Library.
      7. TED Talks.
      8. Edge Videos
      9. CERN Webcast Service.
      10. Dean LeBaron's Video Casts.

    4. Other Announcements Bookmark and Share


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