Complexity Digest 2012.04

2012/02/17

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

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Content

  1. How the Scientific Community Reacts to Newly Submitted Preprints: Article Downloads, Twitter Mentions, and Citations, arXiv
    1. The Pulse of News in Social Media: Forecasting Popularity, arXiv
    2. An Exploration of Social Identity: The Geography and Politics of News-Sharing Communities in Twitter, NECSI
  2. Nanosecond Trading Could Make Markets Go Haywire, Wired
    1. The mathematical equation that caused the banks to crash, The Observer
  3. Critical Truths About Power Laws, Science
  4. Evolution: Adapted to culture, Nature
  5. Stone Age Distributed Computing, arXiv
  6. The Dynamics of Internet Traffic: Self-similarity, Self-organization and Complex Phenomena, Advances in Complex Systems
  7. A Logic-Gated Nanorobot for Targeted Transport of Molecular Payloads, Science
  8. Health policy: Regulate alcohol for global health, Science
  9. A Tiny Window Opens Into Lake Vostok, While a Vast Continent Awaits, Science
  10. Effects of time window size and placement on the structure of aggregated networks, arXiv
  11. The smallest refrigerators can reach maximal efficiency, J. Phys. A: Math. Theor.
  12. Prions are a common mechanism for phenotypic inheritance in wild yeasts, Nature
  13. Peek into Isaac Newton's theology papers, New Scientist
  14. The Statistics of Urban Scaling and their Connection to Zipf's Law, SFI Working Papers
  15. Quantifying the complexity of random Boolean networks, arXiv
  16. Nonequilibrium phase transition of contact processes with the Kauffman NK model, Phys. Rev. E
  17. Tipping Points, SFI Working Papers
  18. Scaling Behavior of Threshold Epidemics, arXiv
  19. Book Announcements
    1. Complexity Theories of Cities Have Come of Age: An Overview with Implications to Urban Planning and Design, Springer
    2. Liars and Outliers: Enabling the Trust that Society Needs to Thrive, Wiley
    3. Connectome: How the Brain's Wiring Makes Us Who We Are, Houghton Mifflin Harcourt
    4. This Will Make You Smarter: New Scientific Concepts to Improve Your Thinking, Harper Perennial
    5. Sociophysics: A Physicist's Modeling of Psycho-political Phenomena, Springer
  20. Links & Snippets
    1. Other Publications
    2. Event Announcements
    3. Video Announcements
    4. Other Announcements

  1. How the Scientific Community Reacts to Newly Submitted Preprints: Article Downloads, Twitter Mentions, and Citations, arXiv Next Article Bookmark and Share

    Abstract: We analyze the online response of the scientific community to the preprint publication of scholarly articles. We employ a cohort of 4,606 scientific articles submitted to the preprint database arXiv.org between October 2010 and April 2011. We study three forms of reactions to these preprints: how they are downloaded on the arXiv.org site, how they are mentioned on the social media site Twitter, and how they are cited in the scholarly record. We perform two analyses. First, we analyze the delay and time span of article downloads and Twitter mentions following submission, to understand the temporal configuration of these reactions and whether significant differences exist between them. Second, we run correlation tests to investigate the relationship between Twitter mentions and both article downloads and article citations. We find that Twitter mentions follow rapidly after article submission and that they are correlated with later article downloads and later article citations, indicating that social media may be an important factor in determining the scientific impact of an article.
    Editor's Note: Take home message: tweet about your preprints.

    1. The Pulse of News in Social Media: Forecasting Popularity, arXiv Next Article Bookmark and Share

      Abstract: News articles are extremely time sensitive by nature. There is also intense competition among news items to propagate as widely as possible. Hence, the task of predicting the popularity of news items on the social web is both interesting and challenging. Prior research has dealt with predicting eventual online popularity based on early popularity. It is most desirable, however, to predict the popularity of items prior to their release, fostering the possibility of appropriate decision making to modify an article and the manner of its publication. In this paper, we construct a multi-dimensional feature space derived from properties of an article and evaluate the efficacy of these features to serve as predictors of online popularity. We examine both regression and classification algorithms and demonstrate that despite randomness in human behavior, it is possible to predict ranges of popularity on twitter with an overall 84% accuracy. Our study also serves to illustrate the differences between traditionally prominent sources and those immensely popular on the social web.

    2. An Exploration of Social Identity: The Geography and Politics of News-Sharing Communities in Twitter, NECSI Next Article Bookmark and Share

      Excerpt: The importance of collective social action in current events is manifest in the Arab Spring and Occupy movements. Electronic social media have become a pervasive channel for social interactions, and a basis of collective social response to information. The study of social media can reveal how individual actions combine to become the collective dynamics of society. Characterizing the groups that form spontaneously may reveal both how individuals self-identify and how they will act together. Here we map the social, political, and geographical properties of news-sharing communities on Twitter (…)

  2. Nanosecond Trading Could Make Markets Go Haywire, Wired Next Article Bookmark and Share

    Excerpt: The afternoon of May 6, 2010 was among the strangest in economic history. Starting at 2:42 p.m. EDT, the Dow Jones stock index fell 600 points in just 6 minutes. Its nadir represented the deepest single-day decline in that market’s 114-year history. By 3:07 p.m., the index had rebounded. The “flash crash,” as it came to be known, was big, unexpected and scary " and a new study says flash events actually happen routinely, at speeds so fast they don’t register on regular market records, with potentially troubling consequences for market stability.

    1. The mathematical equation that caused the banks to crash, The Observer Next Article Bookmark and Share

      Excerpt: It was the holy grail of investors. The Black-Scholes equation, brainchild of economists Fischer Black and Myron Scholes, provided a rational way to price a financial contract when it still had time to run. It was like buying or selling a bet on a horse, halfway through the race. It opened up a new world of ever more complex investments, blossoming into a gigantic global industry. But when the sub-prime mortgage market turned sour, the darling of the financial markets became the Black Hole equation, sucking money out of the universe in an unending stream.

  3. Critical Truths About Power Laws, Science Next Article Bookmark and Share

    Excerpt: A striking feature that has attracted considerable attention is the apparent ubiquity of power-law relationships in empirical data. However, although power laws have been reported in areas ranging from finance and molecular biology to geophysics and the Internet, the data are typically insufficient and the mechanistic insights are almost always too limited for the identification of power-law behavior to be scientifically useful (…) even most statistically “successful” calculations of power laws offer little more than anecdotal value.
    • Source: Critical Truths About Power Laws, Michael P. H. Stumpf, Mason A. Porter, DOI: 10.1126/science.1216142, Science Vol. 335 no. 6069 pp. 665-666, 2012/02/10

  4. Evolution: Adapted to culture, Nature Next Article Bookmark and Share

    Summary:
    • A capacity for culture makes humans unique
    • Transmitting technology and skills is our strategy for survival
    • We became ultra-social through visual theft, the stealing of others' ideas
    • Language evolved from a need to negotiate
    • Evolution has honed the range of our talents

  5. Stone Age Distributed Computing, arXiv Next Article Bookmark and Share

    Abstract: We introduce a new model for distributed computing performed by networks of sub-microprocessor devices.

  6. The Dynamics of Internet Traffic: Self-similarity, Self-organization and Complex Phenomena, Advances in Complex Systems Next Article Bookmark and Share

    Abstract: The Internet is one of the largest and most complex communication and information exchange networks ever created. Therefore, its dynamics and traffic unsurprisingly take on a rich variety of complex dynamics, self-organization, and other phenomena that have been researched for years. This paper is a review of the complex dynamics of Internet traffic. Departing from normal treatises, we will take a view from both the network engineering and physics perspectives showing the strengths and weaknesses as well as insights of both. In addition, many less covered phenomena such as traffic oscillations, BGP storms, and comparisons of the Internet and biological models will be covered.

  7. A Logic-Gated Nanorobot for Targeted Transport of Molecular Payloads, Science Next Article Bookmark and Share

    Abstract: We describe an autonomous DNA nanorobot capable of transporting molecular payloads to cells, sensing cell surface inputs for conditional, triggered activation, and reconfiguring its structure for payload delivery. The device can be loaded with a variety of materials in a highly organized fashion and is controlled by an aptamer-encoded logic gate, enabling it to respond to a wide array of cues. We implemented several different logical AND gates and demonstrate their efficacy in selective regulation of nanorobot function. As a proof of principle, nanorobots loaded with combinations of antibody fragments were used in two different types of cell-signaling stimulation in tissue culture. Our prototype could inspire new designs with different selectivities and biologically active payloads for cell-targeting tasks.

  8. Health policy: Regulate alcohol for global health, Science Next Article Bookmark and Share

    Excerpt: About 2.5 million deaths a year, almost 4% of all deaths worldwide, are attributed to alcohol " more than the number of deaths caused by HIV/AIDS, tuberculosis or malaria. Alcohol consumption is the world's third-largest risk factor for health burden; in middle-income countries, which constitute almost half of the world's population, it is the greatest risk (…)

  9. A Tiny Window Opens Into Lake Vostok, While a Vast Continent Awaits, Science Next Article Bookmark and Share

    Excerpt: They were slowed by annual evacuations and international concerns about their strategy, but after 2 decades they finally did it. On 8 February, the Russian Arctic and Antarctic Research Institute (AARI) announced that a team of its engineers and scientists had drilled through nearly 4 kilometers of Antarctic ice to open what it called a “small window” into Lake Vostok, a dark, mysterious subglacial lake that has likely been cut off from the rest of the planet for millions of years.

  10. Effects of time window size and placement on the structure of aggregated networks, arXiv Next Article Bookmark and Share

    Excerpt: Complex networks are often constructed by aggregating empirical data over time, such that a link represents the existence of interactions between the endpoint nodes and the link weight represents the intensity of such interactions within the aggregation time window. The resulting networks are then often considered static. More often than not, the aggregation time window is dictated by the availability of data, and the effects of its length on the resulting networks are rarely considered. Here, we address this question by studying the structural features of networks emerging from aggregating empirical data over different time intervals, focussing on networks derived from time-stamped, anonymized mobile telephone call records. Our results show that short aggregation intervals yield networks where strong links associated with dense clusters dominate (…)

  11. The smallest refrigerators can reach maximal efficiency, J. Phys. A: Math. Theor. Next Article Bookmark and Share

    Abstract: We investigate whether size imposes a fundamental constraint on the efficiency of small thermal machines. We analyse in detail a model of a small self-contained refrigerator consisting of three qubits. We show analytically that this system can reach the Carnot efficiency, thus demonstrating that there exists no complementarity between size and efficiency.

  12. Prions are a common mechanism for phenotypic inheritance in wild yeasts, Nature Next Article Bookmark and Share

    Excerpts: The self-templating conformations of yeast prion proteins act as epigenetic elements of inheritance. Yeast prions might provide a mechanism for generating heritable phenotypic diversity that promotes survival in fluctuating environments and the evolution of new traits. However, this hypothesis is highly controversial. Prions that create new traits have not been found in wild strains, leading to the perception that they are rare ‘diseases’ of laboratory cultivation. Here we biochemically test approximately 700 wild strains of [yeast] (…) and find these prions in many. (…) we genetically screened for unknown prion elements. Fully one-third of wild strains harboured them. These, too, created diverse, often beneficial phenotypes. Thus, prions broadly govern heritable traits in nature, in a manner that could profoundly expand adaptive opportunities.

  13. Peek into Isaac Newton's theology papers, New Scientist Next Article Bookmark and Share

    Excerpt: Besides mathematics and physics, Newton's interests spread into alchemy and theology, and now a collection of around 7,500 of his original manuscripts, mainly on theology, have been digitised and launched online by the National Library of Israel in Jerusalem. The handwritten papers show his feverish dedication to this work, which includes investigations in Hebrew and Greek as he tried to unlock the secrets of ancient texts.

  14. The Statistics of Urban Scaling and their Connection to Zipf's Law, SFI Working Papers Next Article Bookmark and Share

    Excerpts: Urban scaling relations characterizing how diverse properties of cities vary on average with their population size have recently been shown to be a general quantitative property of many urban systems around the world. (…) Here, we build a self-consistent statistical framework that characterizes the joint probability distributions of urban indicators and city population sizes across an urban system. To develop this framework empirically we use one of the most granular and stochastic urban indicators available, specifically measuring homicides in cities of Brazil, Colombia and Mexico (…)

  15. Quantifying the complexity of random Boolean networks, arXiv Next Article Bookmark and Share

    Abstract: We study two measures of the complexity of heterogeneous extended systems, taking random Boolean networks as prototypical cases. A measure defined by Shalizi et al. for cellular automata, based on a criterion for optimal statistical prediction [Shalizi et al., Phys. Rev. Lett. 93, 118701 (2004)], does not distinguish between the spatial inhomogeneity of the ordered phase and the dynamical inhomogeneity of the disordered phase. A modification in which complexities of individual nodes are calculated yields vanishing complexity values for networks in the ordered and critical regimes and for highly disordered networks, peaking somewhere in the disordered regime. Individual nodes with high complexity are the ones that pass the most information from the past to the future, a quantity that depends in a nontrivial way on both the Boolean function of a given node and its location within the network.

  16. Nonequilibrium phase transition of contact processes with the Kauffman NK model, Phys. Rev. E Next Article Bookmark and Share

    Abstract: We consider a multistate contact process (CP) in which new particles are created with probabilities that depend on the fitness of the parent particle and with mutations that occur at the time of creation. The fitness is determined by the Kauffman NK model. Using Monte Carlo simulations, we show that such an evolutional CP exhibits critical behaviors that differ from the basic CP. In addition, we present numerical results suggesting that the fitness averaged over surviving particles exhibits a maximum value at the critical point.

  17. Tipping Points, SFI Working Papers Next Article Bookmark and Share

    Excerpt: This paper formally defines tipping points as a discontinuity between current and future states of a system and introduces candidate measures of when a system tips based on changes in the probability distribution over future states.
    • Source: Tipping Points, PJ Lamberson, Scott E. Page, DOI: SFI-WP 12-02-002, SFI Working Papers

  18. Scaling Behavior of Threshold Epidemics, arXiv Next Article Bookmark and Share

    Abstract: We study the classic Susceptible-Infected-Recovered (SIR) model for the spread of an infectious disease. In this stochastic process, there are two competing mechanism: infection and recovery. Susceptible individuals may contract the disease from infected individuals, while infected ones recover from the disease at a constant rate and are never infected again. Our focus is the behavior at the epidemic threshold where the rates of the infection and recovery processes balance. In the infinite population limit, we establish analytically scaling rules for the time-dependent distribution functions that characterize the sizes of the infected and the recovered sub-populations. Using heuristic arguments, we also obtain scaling laws for the size and duration of the epidemic outbreaks as a function of the total population. We perform numerical simulations to verify the scaling predictions and discuss the consequences of these scaling laws for near-threshold epidemic outbreaks.

  19. Book Announcements Next Article Bookmark and Share

    1. Complexity Theories of Cities Have Come of Age: An Overview with Implications to Urban Planning and Design, Springer Next Article Bookmark and Share

      Summary:
      Today, our cities are an embodiment of the complex, historical evolution of knowledge, desires and technology. Our planned and designed activities co-evolve with our aspirations, mediated by the existing technologies and social structures. The city represents the accretion and accumulation of successive layers of collective activity, structuring and being structured by other, increasingly distant cities, reaching now right around the globe. This historical and structural development cannot therefore be understood or captured by any set of fixed quantitative relations. Structural changes imply that the patterns of growth, and their underlying reasons change over time, and therefore that any attempt to control the morphology of cities and their patterns of flow by means of planning and design, must be dynamical, based on the mechanisms that drive the changes occurring at a given moment. This carefully edited post-proceedings volume gathers a snapshot view by leading researchers in field, of current complexity theories of cities. In it, the achievements, criticisms and potentials yet to be realized are reviewed and the implications to planning and urban design are assessed.

    2. Liars and Outliers: Enabling the Trust that Society Needs to Thrive, Wiley Next Article Bookmark and Share

      Summary:
      When we think about trust, we naturally think about personal relationships or bank vaults. That's too narrow. Trust is much broader, and much more important. Nothing in society works without trust. It's the foundation of communities, commerce, democracy-everything. In this insightful and entertaining book, Schneier weaves together ideas from across the social and biological sciences to explain how society induces trust. He shows how trust works and fails in social settings, communities, organizations, countries, and the world. In today's hyper-connected society, understanding the mechanisms of trust is as important as understanding electricity was a century ago. Issues of trust and security are critical to solving problems as diverse as corporate responsibility, global warming, and our moribund political system. After reading Liars and Outliers, you'll think about social problems, large and small, differently.

    3. Connectome: How the Brain's Wiring Makes Us Who We Are, Houghton Mifflin Harcourt Next Article Bookmark and Share

      Summary:
      We know that each of us is unique, but science has struggled to pinpoint where, precisely, our uniqueness resides. Is it in our genes? The structure of our brains? Our genome may determine our eye color and even aspects of our personality. But our friendships, failures, and passions also shape who we are. The question is: how? Sebastian Seung, a professor at MIT, is on a quest to discover the biological basis of identity. He believes it lies in the pattern of connections between the brain's neurons, which change slowly over time as we learn and grow. The connectome, as it's called, is where our genetic inheritance intersects with our life experience. It's where nature meets nurture. Seung introduces us to the dedicated researchers who are mapping the brain's connections, neuron by neuron, synapse by synapse. It is a monumental undertaking-the scientific equivalent of climbing Mount Everest-but if they succeed, it could reveal the basis of personality, intelligence, memory, and perhaps even mental disorders.

    4. This Will Make You Smarter: New Scientific Concepts to Improve Your Thinking, Harper Perennial Next Article Bookmark and Share

      Summary:
      What scientific concept would improve everybody's cognitive toolkit? This is the question John Brockman, publisher of Edge.org, posed to the world's most influential thinkers. Their visionary answers flow from the frontiers of psychology, philosophy, economics, physics, sociology, and more. Surprising and enlightening, these insights will revolutionize the way you think about yourself and the world. Daniel Kahneman on the "focusing illusion"; Jonah Lehrer on controlling attention; Richard Dawkins on experimentation; Steven Pinker on win-win negotiating; Daniel C. Dennett on benefiting from cycles; Frank Wilczek on the brain's hidden layers; V. S. Ramachandran on paradigm shifts; Matt Ridley on tapping collective intelligence; Lisa Randall on effective theorizing (...)

    5. Sociophysics: A Physicist's Modeling of Psycho-political Phenomena, Springer Next Article Bookmark and Share

      Summary:
      Do humans behave much like atoms? Sociophysics, which uses tools and concepts from the physics of disordered matter to describe some aspects of social and political behavior, answers in the affirmative. But advocating the use of models from the physical sciences to understand human behavior could be perceived as tantamount to dismissing the existence of human free will and also enabling those seeking manipulative skills . This thought-provoking book argues it is just the contrary. Indeed, future developments and evaluation will either show sociophysics to be inadequate, thus supporting the hypothesis that people can primarily be considered to be free agents, or valid, thus opening the path to a radically different vision of society and personal responsibility. This book attempts to explain why and how humans behave much like atoms, at least in some aspects of their collective lives, and then proposes how this knowledge can serve as a unique key to a dramatic leap forwards in achieving more social freedom in the real world. At heart, sociophysics and this book are about better comprehending the richness and potential of our social interaction, and so distancing ourselves from inanimate atoms.

  20. Links & Snippets Next Article Bookmark and Share

    1. Other Publications Next Article Bookmark and Share

      1. Species Diversity in Rock-Paper-Scissors Game Coupling with Levy Flight, Dong Wang, Qian Zhuang, Jing Zhang, Zengru Di, 2012/02/14, arXiv:1202.2951
      2. Optimal migration promotes the outbreak of cooperation in heterogeneous populations, Frank Schweitzer, Laxmidhar Behera, 2012/02/6, arXiv:1202.1201

    2. Event Announcements Next Article Bookmark and Share

      1. WIVACE 2012 Italian Workshop on Artificial Life and Evolutionary Computation "Artificial Life, Evolution and Complexity" , Parma, Italy, 2012/02/20-21
      2. 3rd Workshop on Complex Networks, Melbourne, Florida, USA, 2012/03/7-9
      3. evostar - the main european events on evolutionary computation eurogp, evocop, evobio, evomusart and evoapplications, Málaga, Spain, 2012/03/11-13
      4. 9th International Conference on the Evolution of Language (Evolang IX), Kyoto, Japan, 2012/03/13-16
      5. IWSOS'12 (Sixth International Workshop on Self-Organizing Systems), Delft, The Netherlands, 2012/03/15-16
      6. 5th International Nonlinear Science Conference 2012, Barcelona, Spain, 2012/03/15-17
      7. 6th International Workshop on Natural Computing, Tokyo, Japan, 2012/03/28-30
      8. IPCAT 2012: Ninth International Conference on Information Processing in Cells and Tissues, Cambridge, United Kingdom, 2012/03/31-04/02
      9. 21st European Meeting on Cybernetics and Systems Research, Vienna, Austria, 2012/04/10-13
      10. Collective Intelligence 2012, Cambridge, MA, USA, 2012/04/18-20
      11. The Fifth IFAC Symposium on Fractional Differentiation and Its Applications - FDA12, Nanjing, China, 2012/05/14-17
      12. The Science of Complexity: Understanding the Global Financial Crisis, Arlington, Virginia, 2012/05/16-18
      13. International Spring School in Natural Computing (SSNC 2012), Tarragona, Spain, 2012/05/28-06/1
      14. 1st Annual Conference on Complexity and Human Experience: Modeling Complexity in the Humanities and Social Sciences, Charlotte, NC, USA, 2012/05/30-06/01
      15. MABS’12 - The Thirteenth International Workshop on Multi-Agent-Based Simulation " Multi-Agent Simulation of/and the Society, Valencia, Spain, 2012/06/4-5
      16. 2012 IEEE World Congress on Computational Intelligence, Brisbane, Australia, 2012/06/10-15
      17. CiE 2012 Turing Centenary conference: How the World Computes, Cambridge, UK, 2012/06/18-23
      18. International Conference on Information Society (i-Society 2012), London, UK, 2012/06/25-28
      19. 8th International Conference on Intelligent Environments (IE'12), Guanajuato, Mexico, 2012/06/26-29
      20. Cellular Automata Algorithms & Architectures (CAAA 2012), Madrid, Spain, 2012/07/2-6
      21. Third Summer School of the European Social Simulation Association (ESSA), Toulouse, France, 2012/07/2-6
      22. 2012 Genetic and Evolutionary Computation Conference (GECCO 2012), Philadelphia, USA, 2012/07/7-11
      23. 25th European Conference on Operational Research, Vilnius, Lithuania, 2012/07/8-11
      24. ALife XIII: The Thirteenth International Conference on the Simulation and Synthesis of Living Systems, East Lansing, Michigan, USA, 2012/08/19-22
      25. 12th International Conference on Adaptive Behaviour (SAB2012), Odense, Denmark, 2012/08/27-31
      26. The 11th International Conference on Artificial Immune Systems - ICARIS 2012, Taormina, Italy, 2012/08/28-31
      27. 12th International Conference on Parallel Problem Solving From Nature (PPSN2012), Taormina, Italy, 2012/09/1-5
      28. ECCS'12: European Conference on Complex Systems, Brussels, Belgium, 2012/09/3-7
      29. 6th IEEE International Conference on Self-Adaptive and Self-Organizing Systems (SASO 2012), Lyon, France, 2012/09/10-14
      30. Interdisciplinary Symposium on Complex Systems, Kos island, Greece, 2012/09/19-25
      31. 10th International Conference on Cellular Automata for Research and Industry (ACRI 2012), Santorini Island, Greece, 2012/09/24-27
      32. International Joint Conference on Computational Intelligence, Barcelona, Spain, 2012/10/5-7
      33. IBERAMIA 2012: 13th Ibero-American Conference on Artificial Intelligence, Cartagena de Indias, Colombia, 2012/11/13-16

    3. Video Announcements Next Article Bookmark and Share

      1. Complexity Digest videos and Webcast Archive.
      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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