31 January 2013

The Evolutionary Origins of Modularity

By simulating 25,000 generations of evolution within computers, Cornell University engineering and robotics researchers have discovered why biological networks tend to be organized as modules -- a finding that will lead to a deeper understanding of the evolution of complexity.

The team discovered that evolution produces modules not because they produce more adaptable designs, but because modular designs have fewer and shorter network connections, which are costly to build and maintain. As it turned out, it was enough to include a "cost of wiring" to make evolution favor modular architectures.

To test the theory, the researchers simulated the evolution of networks with and without a cost for network connections.
"Once you add a cost for network connections, modules immediately appear. Without a cost, modules never form. The effect is quite dramatic," says Clune.
The results may help explain the near-universal presence of modularity in biological networks as diverse as neural networks -- such as animal brains -- and vascular networks, gene regulatory networks, protein-protein interaction networks, metabolic networks and even human-constructed networks such as the Internet.
"Being able to evolve modularity will let us create more complex, sophisticated computational brains," says Clune.
Says Lipson: "We've had various attempts to try to crack the modularity question in lots of different ways. This one by far is the simplest and most elegant."

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27 January 2013

How Organisms Evolve New Functions (Theory and Research)

"Evolution in Four Dimensions", trace four 'dimensions' in evolution: 
* Genetic
Epigenetic (or non-DNA cellular transmission of traits)
Symbolic (transmission through language and other forms of symbolic communication). 

Eva Jablonka and Marion Lamb argue that there is more to heredity than genes. These systems, they argue, can all provide variations on which natural selection can act. Evolution in Four Dimensions offers a richer, more complex view of evolution than the gene-based, one-dimensional view held by many today. The new synthesis advanced by Jablonka and Lamb makes clear that induced and acquired changes also play a role in evolution.

Source: Lecture (bloggpost)


A team of researchers has documented the step-by-step process in which an organisms evolve new functions. The research decodes how E. colibacteria supplement a traditional diet of glucose with an extra course of citrate.

The 1st stage was potentiation, when the E. coli accumulated at least two mutations that set the stage for later events. The 2nd step, actualization, is when the bacteria first began eating citrate, but only just barely nibbling at it. The 3rd final stage, refinement, involved mutations that greatly improved the initially weak function. This allowed the citrate eaters to wolf down their new food source and to become dominant in the population.

Source: link1, link2

20 January 2013

House price indicators

I think it's just a matter of time before 'static tables' is a thing of the past.

Source: link

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19 January 2013

New World Record for Solar Cell Efficiency

Jan. 18, 2013 — In a remarkable feat, scientists at Empa, the Swiss Federal Laboratories for Materials Science and Technology, have developed thin film solar cells on flexible polymer foils with a new record efficiency of 20.4% for converting sunlight into electricity. The cells are based on CIGS semiconducting material (copper indium gallium (di)selenide) known for its potential to provide cost-effective solar electricity. The technology is currently awaiting scale-up for industrial applications.

Over the years the laboratory has boosted the photovoltaic conversion efficiency of flexible CIGS solar cells time and again, from 12.8% in 1999 – the group’s first world record – to 14.1% in 2005, 17.6% in 2010 and 18.7% in 2011.
What’s more, Empa’s new record efficiency for flexible solar cells now even exceeds the record value of 20.3% for CIGS solar cells on glass substrates – and equals the highest efficiencies for polycrystalline silicon wafer-based solar cells. 

Thin film, lightweight and flexible high-performance solar modules are attractive for numerous applications such as solar farms, roofs and facades of buildings, automobiles and portable electronics and can be produced using continuous roll-to-roll manufacturing processes that offer further cost reductions compared to standard silicon technologies. In other words, they have the potential to enable low-cost solar electricity in the near future. 

Now it is time for the next step, the scale-up of the technology to cover large areas in a cost-efficient roll-to-roll manufacturing process with an industrial partner”, says Gian-Luca Bona the Director of Empa. For this purpose, Empa is collaborating with Flisom, a start-up company involved in industrialization of flexible CIGS solar cells.

Source: link

17 January 2013

Teleportation, Quantumportation or Spinportation

Mathematical Breakthrough Sets out Rules for More Effective Teleportation

Jan. 16, 2013 — For the last ten years, theoretical physicists have shown that the intense connections generated between particles as established in the quantum law of 'entanglement' may hold the key to eventual teleportation of quantum information.