The Era of Emergence
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Control Centrality and Hierarchical Structure in Complex Networks

We introduce the concept of control centrality to quantify the ability of a single node to control a directed weighted network. We calculate the distribution of control centrality for several real networks and find that it is mainly determined by the network’s degree distribution. We show that in a directed network without loops the control centrality of a node is uniquely determined by its layer index or topological position in the underlying hierarchical structure of the network. Inspired by the deep relation between control centrality and hierarchical structure in a general directed network, we design an efficient attack strategy against the controllability of malicious networks.

 

Liu Y-Y, Slotine J-J, Barabási A-L (2012) Control Centrality and Hierarchical Structure in Complex Networks. PLoS ONE 7(9): e44459. http://dx.doi.org/10.1371/journal.pone.0044459


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Social Evolution: New Horizons

Cooperation is a widespread natural phenomenon yet current evolutionary thinking is dominated by the paradigm of selfish competition. Recent advanced in many fronts of Biology and Non-linear Physics are helping to bring cooperation to its proper place. In this contribution, the most important controversies and open research avenues in the field of social evolution are reviewed. It is argued that a novel theory of social evolution must integrate the concepts of the science of Complex Systems with those of the Darwinian tradition. Current gene-centric approaches should be reviewed and complemented with evidence from multilevel phenomena (group selection), the constrains given by the non-linear nature of biological dynamical systems and the emergent nature of dissipative phenomena.

 

Social Evolution: New Horizons
Octavio Miramontes, Og DeSouza

http://arxiv.org/abs/1404.6267


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Jose Ali Vivas's insight:

Cooperation is a widespread natural phenomenon... sure!

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june holley's curator insight, May 3, 4:31 AM

Fascinating article suggesting a new evolutionary theory that recognizes the critical importance of cooperation and mutualism.

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Why we should enable the autocatalytic city

Why we should enable the autocatalytic city | The Era of Emergence | Scoop.it

In this modern age, we think of cities as large institutions or machines. We talk about their failures as failures of management, coordination, governance. We think we could have "better" cities if we could only tune the machine to make it more "efficient." The machine model is implicit in the popular language around "smart cities." The promise is that shiny, smart boxes will figure out how to make our cities tick by smoothing traffic flow, monitoring crime and allocating power through smart grids.
We need to think again. Urban centers are evolving organisms, not engineering problems. Although we are able to control parts of a city -- central business districts, mass-transit systems, water distribution -- we will never hold and understand the whole. Cities are dynamic, complex-adaptive systems composed of millions of relatively free-willed individuals who each day make hundreds of individual decisions that set in motion consequences leading to a million other decisions.


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Viktor Markowski's curator insight, March 30, 2013 10:12 AM

Bottom-up growth, driven by citizens, trumps central command.

luiy's curator insight, April 2, 2013 5:33 AM

That call, though, rests on an unquestioned assumption about cities. In this modern age, we think of cities as large institutions or machines. We talk about their failures as failures of management, coordination, governance. We think we could have "better" cities if we could only tune the machine to make it more "efficient." The machine model is implicit in the popular language around "smart cities." The promise is that shiny, smart boxes will figure out how to make our cities tick by smoothing traffic flow, monitoring crime and allocating power through smart grids.

 

We need to think again. Urban centers are evolving organisms, not engineering problems. Although we are able to control parts of a city -- central business districts, mass-transit systems, water distribution -- we will never hold and understand the whole. Cities are dynamic, complex-adaptive systems composed of millions of relatively free-willed individuals who each day make hundreds of individual decisions that set in motion consequences leading to a million other decisions.....

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Global Agenda Council on Complex Systems 2012

Global Agenda Council on Complex Systems 2012 | The Era of Emergence | Scoop.it

Leaders in the public and private sectors are facing unprecedented challenges as they operate and make decisions in a context of increasing complexity. Hyper-connectivity calls into question many traditional problem-solving approaches – regarding diverse matters, from urban population growth to global capital flows – and it limits our capacity to manage these problems. At the same time, opportunities for solutions – via which to deliver greater benefits for stakeholders, cutting across traditional silos and offering more sustainability – are growing.

The Global Agenda Council on Complex Systems examines how insights gleaned from complexity science and systems analysis can best be applied to improve the thoroughness and quality of decision-making and to deliver better results for larger numbers of beneficiaries worldwide.


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Guaranteeing global synchronization in networks with stochastic interactions

Guaranteeing global synchronization in networks with stochastic interactions | The Era of Emergence | Scoop.it

We design the interactions between oscillators communicating via variably delayed pulse coupling to guarantee their synchronization on arbitrary network topologies. We identify a class of response functions and prove convergence to network-wide synchrony from arbitrary initial conditions. Synchrony is achieved if the pulse emission is unreliable or intentionally probabilistic. These results support the design of scalable, reliable and energy-efficient communication protocols for fully distributed synchronization as needed, e.g., in mobile phone networks, embedded systems, sensor networks and autonomously interacting swarm robots.

 

Johannes Klinglmayr et al 2012 New J. Phys. 14 073031
http://dx.doi.org/10.1088/1367-2630/14/7/073031


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On the necessity of complexity

Wolfram's Principle of Computational Equivalence (PCE) implies that universal complexity abounds in nature. This paper comprises three sections. In the first section we consider the question why there are so many universal phenomena around. So, in a sense, we week a driving force behind the PCE if any. We postulate a principle GNS that we call the Generalized Natural Selection Principle that together with the Church-Turing Thesis is seen to be equivalent to a weak version of PCE. In the second section we ask the question why we do not observe any phenomena that are complex but not-universal. We choose a cognitive setting to embark on this question and make some analogies with formal logic. In the third and final section we report on a case study where we see rich structures arise everywhere.

 

On the necessity of complexity

Joost J. Joosten

http://arxiv.org/abs/1211.1878


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How the Scientific Community Reacts to Newly Submitted Preprints: Article Downloads, Twitter Mentions, and Citations

How the Scientific Community Reacts to Newly Submitted Preprints: Article Downloads, Twitter Mentions, and Citations | The Era of Emergence | Scoop.it

We analyze the online response to the preprint publication of a cohort of 4,606 scientific articles submitted to the preprint database arXiv.org between October 2010 and May 2011. We study three forms of responses to these preprints: downloads on the arXiv.org site, mentions on the social media site Twitter, and early citations 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 one precedes or follows the other. Second, we run regression and correlation tests to investigate the relationship between Twitter mentions, arXiv downloads, and article citations. We find that Twitter mentions and arXiv downloads of scholarly articles follow two distinct temporal patterns of activity, with Twitter mentions having shorter delays and narrower time spans than arXiv downloads. We also find that the volume of Twitter mentions is statistically correlated with arXiv downloads and early citations just months after the publication of a preprint, with a possible bias that favors highly mentioned articles.

 

Shuai X, Pepe A, Bollen J (2012) How the Scientific Community Reacts to Newly Submitted Preprints: Article Downloads, Twitter Mentions, and Citations. PLoS ONE 7(11): e47523. http://dx.doi.org/10.1371/journal.pone.0047523


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Control Centrality and Hierarchical Structure in Complex Networks

We introduce the concept of control centrality to quantify the ability of a single node to control a directed weighted network. We calculate the distribution of control centrality for several real networks and find that it is mainly determined by the network’s degree distribution. We show that in a directed network without loops the control centrality of a node is uniquely determined by its layer index or topological position in the underlying hierarchical structure of the network. Inspired by the deep relation between control centrality and hierarchical structure in a general directed network, we design an efficient attack strategy against the controllability of malicious networks.

 

Liu Y-Y, Slotine J-J, Barabási A-L (2012) Control Centrality and Hierarchical Structure in Complex Networks. PLoS ONE 7(9): e44459. http://dx.doi.org/10.1371/journal.pone.0044459


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Impossible Cookware and Other Triumphs of the Penrose Tile

Impossible Cookware and Other Triumphs of the Penrose Tile | The Era of Emergence | Scoop.it

Nobody knows how the story of forbidden symmetry ends. Mathematicians continue to explore the properties of Penrose tiles. Quasicrystals remain the subject of both basic and applied research. But it has been an incredible journey so far. In the past 40 years, five-axis symmetry has gone from impractical to valuable, from unnatural to perfectly natural, from forbidden to mainstream. It’s a transformation for which we can thank two scientists who pushed past conventional wisdom to uncover a remarkable new form of infinite variation in nature.


http://nautil.us/issue/13/symmetry/impossible-cookware-and-other-triumphs-of-the-penrose-tile


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Eli Levine's curator insight, May 2, 7:44 AM

Indeed, what is history, but the near repeating patterns of events, brought on by a complicated set of pre-conditions and pre-dispositions?  History, like Penrose Tiles, never quite entirely repeats and, true to quantum mechanics, it changes with observation, especially by people who wield power, control and influence in our world.  Very interesting that these patterns may also exist in our social worlds as well.

 

Think about it.

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Leaders in Big Data

Discussing the evolution, current opportunities and future trends in big data
Presented by Google and the Fung Institute at UC Berkeley

SPEAKERS:

Moderator: Hal Varian, an economist specializing in microeconomics and information economics. He is the Chief Economist at Google and he holds the title of emeritus professor at the University of California, Berkeley where he was founding dean of the School of Information.

Panelists:
Theo Vassilakis, Principal Engineer/Engineering Director at Google
Gustav Horn, Senior Global Consulting Engineer, Hadoop at NetApp
Charles Fan, Senior Vice President at VMware in strategic R&D


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Evolutionary advantages of adaptive rewarding

Our well-being depends on both our personal success and the success of our society. The realization of this fact makes cooperation an essential trait. Experiments have shown that rewards can elevate our readiness to cooperate, but since giving a reward inevitably entails paying a cost for it, the emergence and stability of such behavior remains elusive. Here we show that allowing for the act of rewarding to self-organize in dependence on the success of cooperation creates several evolutionary advantages that instill new ways through which collaborative efforts are promoted. Ranging from indirect territorial battle to the spontaneous emergence and destruction of coexistence, phase diagrams and the underlying spatial patterns reveal fascinatingly rich social dynamics that explain why this costly behavior has evolved and persevered. Comparisons with adaptive punishment, however, uncover an Achilles heel of adaptive rewarding, coming from over-aggression, which in turn hinders optimal utilization of network reciprocity. This may explain why, despite its success, rewarding is not as firmly embedded into our societal organization as punishment.

 

Evolutionary advantages of adaptive rewarding

Attila Szolnoki and Matjaž Perc 2012 New J. Phys. 14 093016
http://dx.doi.org/10.1088/1367-2630/14/9/093016


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Spontaneous network formation among cooperative RNA replicators

Spontaneous network formation among cooperative RNA replicators | The Era of Emergence | Scoop.it

The origins of life on Earth required the establishment of self-replicating chemical systems capable of maintaining and evolving biological information. In an RNA world, single self-replicating RNAs would have faced the extreme challenge of possessing a mutation rate low enough both to sustain their own information and to compete successfully against molecular parasites with limited evolvability. Thus theoretical analyses suggest that networks of interacting molecules were more likely to develop and sustain life-like behaviour. Here we show that mixtures of RNA fragments that self-assemble into self-replicating ribozymes spontaneously form cooperative catalytic cycles and networks. We find that a specific three-membered network has highly cooperative growth dynamics. When such cooperative networks are competed directly against selfish autocatalytic cycles, the former grow faster, indicating an intrinsic ability of RNA populations to evolve greater complexity through cooperation. We can observe the evolvability of networks through in vitro selection. Our experiments highlight the advantages of cooperative behaviour even at the molecular stages of nascent life.

 

Spontaneous network formation among cooperative RNA replicators

Nilesh Vaidya, Michael L. Manapat, Irene A. Chen, Ramon Xulvi-Brunet, Eric J. Hayden & Niles Lehman

Nature 491, 72–77 (01 November 2012) http://dx.doi.org/10.1038/nature11549


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Life as Thermodynamic Evidence of Algorithmic Structure in Natural Environments

In evolutionary biology, attention to the relationship between stochastic organisms and their stochastic environments has leaned towards the adaptability and learning capabilities of the organisms rather than toward the properties of the environment. This article is devoted to the algorithmic aspects of the environment and its interaction with living organisms. We ask whether one may use the fact of the existence of life to establish how far nature is removed from algorithmic randomness. The paper uses a novel approach to behavioral evolutionary questions, using tools drawn from information theory, algorithmic complexity and the thermodynamics of computation to support an intuitive assumption about the near optimal structure of a physical environment that would prove conducive to the evolution and survival of organisms, and sketches the potential of these tools, at present alien to biology, that could be used in the future to address different and deeper questions. We contribute to the discussion of the algorithmic structure of natural environments and provide statistical and computational arguments for the intuitive claim that living systems would not be able to survive in completely unpredictable environments, even if adaptable and equipped with storage and learning capabilities by natural selection (brain memory or DNA).

 

Zenil, Hector; Gershenson, Carlos; Marshall, James A.R.; Rosenblueth, David A. 2012. "Life as Thermodynamic Evidence of Algorithmic Structure in Natural Environments." Entropy 14, no. 11: 2173-2191.

http://www.mdpi.com/1099-4300/14/11/2173


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On the necessity of complexity

Wolfram's Principle of Computational Equivalence (PCE) implies that universal complexity abounds in nature. This paper comprises three sections. In the first section we consider the question why there are so many universal phenomena around. So, in a sense, we week a driving force behind the PCE if any. We postulate a principle GNS that we call the Generalized Natural Selection Principle that together with the Church-Turing Thesis is seen to be equivalent to a weak version of PCE. In the second section we ask the question why we do not observe any phenomena that are complex but not-universal. We choose a cognitive setting to embark on this question and make some analogies with formal logic. In the third and final section we report on a case study where we see rich structures arise everywhere.

 

On the necessity of complexity

Joost J. Joosten

http://arxiv.org/abs/1211.1878


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The relationship between human behavior and the process of epidemic spreading in a real social network

On the basis of experimental data on interactions between humans we have investigated the process of epidemic spreading in a social network. We found that the distribution of the number of contacts maintained in one day is exponential. Data on frequency and duration of interpersonal interactions are presented. They allow us to simulate the spread of droplet-/-air-borne infections and to investigate the influence of human dynamics on the epidemic spread. Specifically, we investigated the influence of the distribution of frequency and duration of those contacts on magnitude, epidemic threshold and peak timing of epidemics propagating in respective networks. It turns out that a large increase in the magnitude of an epidemic and a decrease in epidemic threshold are visible if and only if both are taken into account. We have found that correlation between contact frequency and duration strongly influences the effectiveness of control measures like mass immunization campaigns.

 

The relationship between human behavior and the process of epidemic spreading in a real social network

A. Grabowski and M. Rosińska

Eur. Phys. J. B (2012) 85: 248
http://dx.doi.org/10.1140/epjb/e2012-20250-1


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