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Complexity Digest's Blog

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What Are Leaders Really For?

December 9, 2011 Comments (0)

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...
HBR Blog Network

An Experimental Study of Homophily in the Adoption of Health Behavior

December 9, 2011 Comments (0)

How does the composition of a population affect the adoption of health behaviors and innovations? Homophily—similarity of social contacts—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...
Science

Luis von Ahn: Massive-scale online collaboration

December 9, 2011 Comments (0)

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...
TED.com

Cheryl Hayashi: The magnificence of spider silk

December 9, 2011 Comments (0)

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...
TED.com

How to Fix World Transportation

December 9, 2011 Comments (0)

Keeping people and goods moving safely and efficiently—whether by land, sea, or air—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,...
BusinessWeek

Complexity in human transportation networks: a comparative analysis of worldwide air transportation and global cargo-ship movements

December 9, 2011 Comments (0)

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...
Eur. Phys. J. B

An Evolution Toward a Programmable Universe

December 9, 2011 Comments (0)

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....
NYTimes.com

Impact of epistasis and pleiotropy on evolutionary adaptation

December 9, 2011 Comments (0)

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...
Proc. R. Soc. B

Empathy and Pro-Social Behavior in Rats

December 9, 2011 Comments (0)

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...
Science

Energetics and the evolution of human brain size

December 9, 2011 Comments (0)

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...
Nature