Complexity Digest 2011.25

2011/12/26

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

Complex wishes for 2012!

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Content

  1. The network takeover, Nature Physics
  2. Between order and chaos, Nature Physics
    1. Information processing in echo state networks at the edge of chaos, Theory in Biosciences
  3. Uninformed Individuals Promote Democratic Consensus in Animal Groups, Science
    1. Decision versus compromise for animal groups in motion, PNAS
  4. To Group or Not to Group?, Science
  5. Antonio Damasio: The quest to understand consciousness, TED.com
  6. Communities, modules and large-scale structure in networks, Nature Physics
    1. Evolution of a modular software network, PNAS
  7. Modelling dynamical processes in complex socio-technical systems, Nature Physics
  8. Collaborative learning in networks, PNAS
    1. Social selection and peer influence in an online social network, PNAS
  9. Detecting Novel Associations in Large Data Sets, Science
  10. Evolution and development of Brain Networks: From Caenorhabditis elegans to Homo sapiens, arXiv
  11. The use of information theory in evolutionary biology, arXiv
  12. Networks formed from interdependent networks, Nature Physics
  13. Converging towards the optimal path to extinction, arXiv
  14. The Diversity Paradox: How Nature Resolves an Evolutionary Dilemma, arXiv
  15. Facing Complexity: Prediction vs. Adaptation, arXiv
  16. A comparative study of Macroscopic Fundamental Diagrams of urban road networks governed by different traffic signal systems, arXiv
  17. The effects of spatially heterogeneous prey distributions on detection patterns in foraging seabirds, arXiv
  18. Slime mould imitation of Belgian transport networks: redundancy, bio-essential motorways, and dissolution, arXiv
  19. Book Announcements
    1. Reinventing Discovery: The New Era of Networked Science, Princeton University Press
    2. Bacteria: The Benign, the Bad, and the Beautiful, Wiley-Blackwell
    3. Currency Wars: The Making of the Next Global Crisis, Portfolio Hardcover
    4. Aerotropolis: The Way We'll Live Next, Farrar, Straus and Giroux
    5. Neurogastronomy: How the Brain Creates Flavor and Why It Matters, Columbia University Press
    6. What Makes Your Brain Happy and Why You Should Do the Opposite, Prometheus Books
    7. Endgame: The End of the Debt Supercycle and How It Changes Everything, Wiley
  20. Links & Snippets
    1. Other Publications
    2. Event Announcements
    3. Video Announcements
    4. Other Announcements

  1. The network takeover, Nature Physics Next Article Bookmark and Share

    Summary: Reductionism, as a paradigm, is expired, and complexity, as a field, is tired. Data-based mathematical models of complex systems are offering a fresh perspective, rapidly developing into a new discipline: network science.
    • Source: The network takeover, Albert-László Barabási, DOI: 10.1038/nphys2188, Nature Physics 8, 14"16, 2011/12/22

  2. Between order and chaos, Nature Physics Next Article Bookmark and Share

    Abstract: What is a pattern? How do we come to recognize patterns never seen before? Quantifying the notion of pattern and formalizing the process of pattern discovery go right to the heart of physical science. Over the past few decades physics’ view of nature’s lack of structure"its unpredictability"underwent a major renovation with the discovery of deterministic chaos, overthrowing two centuries of Laplace’s strict determinism in classical physics. Behind the veil of apparent randomness, though, many processes are highly ordered, following simple rules. Tools adapted from the theories of information and computation have brought physical science to the brink of automatically discovering hidden patterns and quantifying their structural complexity.

    1. Information processing in echo state networks at the edge of chaos, Theory in Biosciences Next Article Bookmark and Share

      Excerpt: We investigate information processing in randomly connected recurrent neural networks. It has been shown previously that the computational capabilities of these networks are maximized when the recurrent layer is close to the border between a stable and an unstable dynamics regime, the so called edge of chaos. The reasons, however, for this maximized performance are not completely understood. We adopt an information-theoretical framework and are for the first time able to quantify the computational capabilities between elements of these networks directly as they undergo the phase transition to chaos. Specifically, we present evidence that both information transfer and storage in the recurrent layer are maximized close to this phase transition, providing an explanation for why guiding the recurrent layer toward the edge of chaos is computationally useful (…)

  3. Uninformed Individuals Promote Democratic Consensus in Animal Groups, Science Next Article Bookmark and Share

    Abstract: Conflicting interests among group members are common when making collective decisions, yet failure to achieve consensus can be costly. Under these circumstances individuals may be susceptible to manipulation by a strongly opinionated, or extremist, minority. It has previously been argued, for humans and animals, that social groups containing individuals who are uninformed, or exhibit weak preferences, are particularly vulnerable to such manipulative agents. Here, we use theory and experiment to demonstrate that, for a wide range of conditions, a strongly opinionated minority can dictate group choice, but the presence of uninformed individuals spontaneously inhibits this process, returning control to the numerical majority. Our results emphasize the role of uninformed individuals in achieving democratic consensus amid internal group conflict and informational constraints.

    1. Decision versus compromise for animal groups in motion, PNAS Next Article Bookmark and Share

      Excerpt: we derive a testable result that adding uninformed individuals improves stability of collective decision making.

  4. To Group or Not to Group?, Science Next Article Bookmark and Share

    Summary: The phenomenon of cooperation between potentially competing individuals raises an interesting question related to evolution: Why should a competitor favor someone else's fitness at the expense of its own? One way to approach this question is through insights on how cooperation and population structure coevolve.
    • Source: To Group or Not to Group?, Eörs Szathmáry, DOI: 10.1126/science.1209548, Science Vol. 334 no. 6063 pp. 1648-1649, 2011/12/23

  5. Antonio Damasio: The quest to understand consciousness, TED.com Next Article Bookmark and Share

    About this talk: Every morning we wake up and regain consciousness -- that is a marvelous fact -- but what exactly is it that we regain? Neuroscientist Antonio Damasio uses this simple question to give us a glimpse into how our brains create our sense of self.

  6. Communities, modules and large-scale structure in networks, Nature Physics Next Article Bookmark and Share

    Abstract: Networks, also called graphs by mathematicians, provide a useful abstraction of the structure of many complex systems, ranging from social systems and computer networks to biological networks and the state spaces of physical systems. In the past decade there have been significant advances in experiments to determine the topological structure of networked systems, but there remain substantial challenges in extracting scientific understanding from the large quantities of data produced by the experiments. A variety of basic measures and metrics are available that can tell us about small-scale structure in networks, such as correlations, connections and recurrent patterns, but it is considerably more difficult to quantify structure on medium and large scales, to understand the ‘big picture’. Important progress has been made, however, within the past few years, a selection of which is reviewed here.

    1. Evolution of a modular software network, PNAS Next Article Bookmark and Share

      Excerpt: “Evolution behaves like a tinkerer” (François Jacob, Science, 1977). Software systems provide a singular opportunity to understand biological processes using concepts from network theory. The Debian GNU/Linux operating system allows us to explore the evolution of a complex network in a unique way. The modular design detected during its growth is based on the reuse of existing code in order to minimize costs during programming. The increase of modularity experienced by the system over time has not counterbalanced the increase in incompatibilities between software packages within modules(…)

  7. Modelling dynamical processes in complex socio-technical systems, Nature Physics Next Article Bookmark and Share

    Abstract: In recent years the increasing availability of computer power and informatics tools has enabled the gathering of reliable data quantifying the complexity of socio-technical systems. Data-driven computational models have emerged as appropriate tools to tackle the study of dynamical phenomena as diverse as epidemic outbreaks, information spreading and Internet packet routing. These models aim at providing a rationale for understanding the emerging tipping points and nonlinear properties that often underpin the most interesting characteristics of socio-technical systems. Here, using diffusion and contagion phenomena as prototypical examples, we review some of the recent progress in modelling dynamical processes that integrates the complex features and heterogeneities of real-world systems.

  8. Collaborative learning in networks, PNAS Next Article Bookmark and Share

    Excerpt: Complex problems in science, business, and engineering typically require some tradeoff between exploitation of known solutions and exploration for novel ones, where, in many cases, information about known solutions can also disseminate among individual problem solvers through formal or informal networks. Prior research on complex problem solving by collectives has found the counterintuitive result that inefficient networks, meaning networks that disseminate information relatively slowly, can perform better than efficient networks for problems that require extended exploration. (…) we found that efficient networks outperformed inefficient networks, even in a problem space with qualitative properties thought to favor inefficient networks.

    1. Social selection and peer influence in an online social network, PNAS Next Article Bookmark and Share

      Excerpt: Disentangling the effects of selection and influence is one of social science's greatest unsolved puzzles: Do people befriend others who are similar to them, or do they become more similar to their friends over time? Recent advances in stochastic actor-based modeling, combined with self-reported data on a popular online social network site, allow us to address this question with a greater degree of precision than has heretofore been possible. Using data on the Facebook activity of a cohort of college students over 4 years, we find that students who share certain tastes in music and in movies, but not in books, are significantly likely to befriend one another (…)

  9. Detecting Novel Associations in Large Data Sets, Science Next Article Bookmark and Share

    Abstract: Identifying interesting relationships between pairs of variables in large data sets is increasingly important. Here, we present a measure of dependence for two-variable relationships: the maximal information coefficient (MIC). MIC captures a wide range of associations both functional and not, and for functional relationships provides a score that roughly equals the coefficient of determination (R^2) of the data relative to the regression function. MIC belongs to a larger class of maximal information-based nonparametric exploration (MINE) statistics for identifying and classifying relationships. We apply MIC and MINE to data sets in global health, gene expression, major-league baseball, and the human gut microbiota and identify known and novel relationships.

  10. Evolution and development of Brain Networks: From Caenorhabditis elegans to Homo sapiens, arXiv Next Article Bookmark and Share

    Abstract: Neural networks show a progressive increase in complexity during the time course of evolution. From diffuse nerve nets in Cnidaria to modular, hierarchical systems in macaque and humans, there is a gradual shift from simple processes involving a limited amount of tasks and modalities to complex functional and behavioral processing integrating different kinds of information from highly specialized tissue. However, studies in a range of species suggest that fundamental similarities, in spatial and topological features as well as in developmental mechanisms for network formation, are retained across evolution. 'Small-world' topology and highly connected regions (hubs) are prevalent across the evolutionary scale, ensuring efficient processing and resilience to internal (e.g. lesions) and external (e.g. environment) changes. Furthermore, in most species, even the establishment of hubs, long-range connections linking distant components, and a modular organization, relies on similar mechanisms. In conclusion, evolutionary divergence leads to greater complexity while following essential developmental constraints.

  11. The use of information theory in evolutionary biology, arXiv Next Article Bookmark and Share

    Abstract: Information is a key concept in evolutionary biology. Information is stored in biological organism's genomes, and used to generate the organism as well as to maintain and control it. Information is also "that which evolves". When a population adapts to a local environment, information about this environment is fixed in a representative genome. However, when an environment changes, information can be lost. At the same time, information is processed by animal brains to survive in complex environments, and the capacity for information processing also evolves. Here I review applications of information theory to the evolution of proteins as well as to the evolution of information processing in simulated agents that adapt to perform a complex task.

  12. Networks formed from interdependent networks, Nature Physics Next Article Bookmark and Share

    Abstract: Complex networks appear in almost every aspect of science and technology. Although most results in the field have been obtained by analysing isolated networks, many real-world networks do in fact interact with and depend on other networks. The set of extensive results for the limiting case of non-interacting networks holds only to the extent that ignoring the presence of other networks can be justified. Recently, an analytical framework for studying the percolation properties of interacting networks has been developed. Here we review this framework and the results obtained so far for connectivity properties of ‘networks of networks’ formed by interdependent random networks.

  13. Converging towards the optimal path to extinction, arXiv Next Article Bookmark and Share

    Abstract: Extinction appears ubiquitously in many fields, including chemical reactions, population biology, evolution, and epidemiology. Even though extinction as a random process is a rare event, its occurrence is observed in large finite populations. Extinction occurs when fluctuations due to random transitions act as an effective force which drives one or more components or species to vanish. Although there are many random paths to an extinct state, there is an optimal path that maximizes the probability to extinction. In this article, we show that the optimal path is associated with the dynamical systems idea of having maximum sensitive dependence to initial conditions. Using the equivalence between the sensitive dependence and the path to extinction, we show that the dynamical systems picture of extinction evolves naturally toward the optimal path in several stochastic models of epidemics.

  14. The Diversity Paradox: How Nature Resolves an Evolutionary Dilemma, arXiv Next Article Bookmark and Share

    Excerpt: Adaptation to changing environments is a hallmark of biological systems. Diversity in traits is necessary for adaptation and can influence the survival of a population faced with novelty. In habitats that remain stable over many generations, stabilizing selection reduces trait differences within populations, thereby appearing to remove the diversity needed for heritable adaptive responses in new environments. Paradoxically, field studies have documented numerous populations under long periods of stabilizing selection and evolutionary stasis that have rapidly evolved under changed environmental conditions. In this article, we review how cryptic genetic variation (CGV) resolves this diversity paradox by allowing populations in a stable environment to gradually accumulate hidden genetic diversity that is revealed as trait differences when environments change. (…)

  15. Facing Complexity: Prediction vs. Adaptation, arXiv Next Article Bookmark and Share

    Abstract: One of the presuppositions of science since the times of Galileo, Newton, Laplace, and Descartes has been the predictability of the world. This idea has strongly influenced scientific and technological models. However, in recent decades, chaos and complexity have shown that not every phenomenon is predictable, even if it is deterministic. If a problem space is predictable, in theory we can find a solution via optimization. Nevertheless, if a problem space is not predictable, or it changes too fast, very probably optimization will offer obsolete solutions. This occurs often when the immediate solution affects the problem itself. An alternative is found in adaptation. An adaptive system will be able to find by itself new solutions for unforeseen situations.

  16. A comparative study of Macroscopic Fundamental Diagrams of urban road networks governed by different traffic signal systems, arXiv Next Article Bookmark and Share

    Excerpt: Using a stochastic cellular automaton model for urban traffic flow, we study and compare Macroscopic Fundamental Diagrams (MFDs) of arterial road networks governed by different types of adaptive traffic signal systems. In particular, we simulate realistic signal systems that include signal linking and adaptive cycle times, and compare their performance against a network using highly adaptive self-organizing traffic signals (…) Our results show that the MFD of the self-organizing traffic signals lies above the MFD for the realistic systems, suggesting that higher adaptivity provides overall better performance and higher capacity.

  17. The effects of spatially heterogeneous prey distributions on detection patterns in foraging seabirds, arXiv Next Article Bookmark and Share

    Excerpt: Many attempts to relate animal foraging patterns to landscape heterogeneity are focused on the analysis of foragers movements. Resource detection or feeding patterns in space and time are not commonly studied, yet they are tightly coupled to landscape properties and add relevant information on foraging behavior. By exploring simple foraging models in unpredictable environments we show that the distribution of intervals between detected prey (detection statistics) is mostly determined by the spatial structure of the prey field and essentially distinct from predator displacement statistics (…)

  18. Slime mould imitation of Belgian transport networks: redundancy, bio-essential motorways, and dissolution, arXiv Next Article Bookmark and Share

    Abstract: Belgium is amongst few artificial countries, established on purpose, when Dutch and French speaking parts were joined in a single unit. This makes Belgium a particularly interesting testbed for studying bio-inspired techniques for simulation and analysis of vehicular transport networks. We imitate growth and formation of a transport network between major urban areas in Belgium using the acellular slime mould Physarum polycephalum. We represent the urban areas with the sources of nutrients. The slime mould spans the sources of nutrients with a network of protoplasmic tubes. The protoplasmic tubes represent the motorways. In an experimental laboratory analysis we compare the motorway network approximated by P. polycephalum and the man-made motorway network of Belgium. We evaluate the efficiency of the slime mould network and the motorway network using proximity graphs.

  19. Book Announcements Next Article Bookmark and Share

    1. Reinventing Discovery: The New Era of Networked Science, Princeton University Press Next Article Bookmark and Share

      Summary:
      In this book Michael Nielsen argues that we are living at the dawn of the most dramatic change in science in more than 300 years. This change is being driven by powerful new cognitive tools, enabled by the internet, which are greatly accelerating scientific discovery. There are many books about how the internet is changing business or the workplace or government, but this is the first book about something much more fundamental: how the internet is transforming the nature of our collective intelligence and how we understand the world. (...)

    2. Bacteria: The Benign, the Bad, and the Beautiful, Wiley-Blackwell Next Article Bookmark and Share

      Summary:
      When most people hear the word "bacteria" they think of food poisoning; infections; and acute, debilitating, or fatal diseases. Yet, while E. coli, strep, and other bacterial pathogens certainly cause their share of misery in the world, they are only a tiny portion of a vast universe of microorganisms-the most basic of life forms. Without them, nothing else could live or grow on Planet Earth. This book introduces you to this diverse, microscopic world and explains the fundamental microbiological concepts you need to explore the life and behavior of bacteria. (...)

    3. Currency Wars: The Making of the Next Global Crisis, Portfolio Hardcover Next Article Bookmark and Share

      Summary:
      Currency wars are one of the most destructive and feared outcomes in international economics. At best, they offer the sorry spectacle of countries' stealing growth from their trading partners. At worst, they degenerate into sequential bouts of inflation, recession, retaliation, and sometimes actual violence. Left unchecked, the next currency war could lead to a crisis worse than the panic of 2008. Currency wars have happened before-twice in the last century alone-and they always end badly. Time and again, paper currencies have collapsed, assets have been frozen, gold has been confiscated, and capital controls have been imposed. (...)

    4. Aerotropolis: The Way We'll Live Next, Farrar, Straus and Giroux Next Article Bookmark and Share

      Summary:
      A new phenomenon is reshaping the way we live and transforming the way we do business: the aerotropolis. A combination of giant airport, planned city, shipping facility and business hub, the aerotropolis will be at the heart of the next phase of globalization. Drawing on a decade's worth of cutting-edge research, this book offers a visionary look at how the metropolis of the future will bring us together - and how, in our globalized, 'flat' world, connecting people and goods is still as important as digital communication. "Aerotropolis" shows us how to make the most of this unparalleled opportunity.

    5. Neurogastronomy: How the Brain Creates Flavor and Why It Matters, Columbia University Press Next Article Bookmark and Share

      Summary:
      Leading neuroscientist Gordon Shepherd embarks on a paradigm-shifting trip through the "human brain flavor system," laying the foundations for a new scientific field: neurogastronomy. Challenging the belief that the sense of smell diminished during human evolution, Shepherd argues that this sense, which constitutes the main component of flavor, is far more powerful and essential than previously believed. He analyzes flavor's engagement with the brain regions that control emotion, food preferences, and cravings, and he even devotes a section to food's role in drug addiction and, building on Marcel Proust's iconic tale of the madeleine, its ability to evoke deep memories.

    6. What Makes Your Brain Happy and Why You Should Do the Opposite, Prometheus Books Next Article Bookmark and Share

      Summary:
      Greece isn't the only country drowning in debt. The Debt Supercycle"when the easily managed, decades-long growth of debt results in a massive sovereign debt and credit crisis"is affecting developed countries around the world, including the United States. For these countries, there are only two options, and neither is good"restructure the debt or reduce it through austerity measures. The book reveals why the world economy is in for an extended period of sluggish growth, high unemployment, and volatile markets punctuated by persistent recessions and reviews global markets, trends in population, government policies, and currencies. (...)

    7. Endgame: The End of the Debt Supercycle and How It Changes Everything, Wiley Next Article Bookmark and Share

      Summary:
      Why do we routinely choose options that don't meet our short-term needs and undermine our long-term goals? Why do we willingly expose ourselves to temptations that undercut our hard-fought progress to overcome addictions? Why are we prone to assigning meaning to statistically common coincidences? Why do we insist we're right even when evidence contradicts us? In this book, David DiSalvo reveals a remarkable paradox: what your brain wants is frequently not what your brain needs. In fact, much of what makes our brains "happy" leads to errors, biases, and distortions, which make getting out of our own way extremely difficult.

  20. Links & Snippets Next Article Bookmark and Share

    1. Other Publications Next Article Bookmark and Share

      1. Advancing the Understanding of Sociospatial Dependencies in Terrorist Networks, Richard M. Medina, George F. Hepner, 2011/10, Transactions in GIS Volume 15, Issue 5, pages 577–597, DOI: 10.1111/j.1467-9671.2011.001281.x
      2. Stability of Synchronized Motion in Complex Networks, Tiago Pereira, 2011/12/10, arXiv:1112.2297
      3. Pervasive Flexibility in Living Technologies through Degeneracy Based Design, James Whitacre, Axel Bender, 2011/12/14, arXiv:1112.3117
      4. Short and Long Range Population Dynamics of the Monarch, Komi Messan, Kyle Smith, Shawn Tsosie, Shuchen Zhu, Sergei Suslov, 2011/12/19, arXiv:1112.3991
      5. Does strong heterogeneity promote cooperation by group interactions?, Matjaz Perc, 2011/12/20, arXiv:1112.4826
      6. Evolution of sustained foraging in 3D environments with physics, Nicolas Chaumont and Christoph Adami, 2011/12/21, arXiv:1112.5116

    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
      25. 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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