Their latest achievement, detailed in a paper published in the January 21 issue of the journal Nature, is a crucial step in creating genetic sensors that might one day provide humans with advance information about temperature, poisons and other potential hazards in the environment by monitoring changes in the bacterium’s blinking rates.

“Programming living cells is one defining goal of the new field of synthetic biology,” said Jeff Hasty, associate professor of biology and bioengineering at UCSD who headed the research team with Lev Tsimring, associate director of UCSD’s BioCircuits Institute.

“Dr. Hasty and colleagues have used powerful genetic tools, backed by decades of detailed knowledge of bacterial processes, to create a system that delivers on the promise of synthetic biology — to engineer living organisms to meet pressing societal needs,” said James Anderson, who oversees computational biology grants at the NIH’s National Institute of General Medical Sciences. “The oscillating system they engineered sets the stage for the development of highly sensitive sensors that could have multiple applications in basic research, biotechnology and medicine.”

“Synchronization of clocks and oscillators in general has been a fascinating subject for physicists and applied mathematicians for centuries,” said Tsimring. “This began with the Dutch mathematician and astronomer Christiaan Huygens, who is credited with its serendipitous discovery in 1665 when he suspended a pair of nearly identical pendulum clocks (which he invented and patented some 8 years earlier) on the same wooden beam.”

“Synchronization plays a crucial role in physics and biology as a way of self-organization of highly regular behavior with less that perfect components. This phenomenon has a myriad of applications in modern technology, from communication networks to GPS. Our study demonstrates how inherently noisy gene oscillators can operate together with beautiful synchronicity and regularity once coupled together in a specific way.”

Over the past decade, researchers have gone from wiring genetic toggle switches and oscillators in living cells to building living circuits capable of pattern generation, noise shaping, edge detection and event counting. In their latest development, the UCSD researchers took advantage of a type of bacterial communication in which bacteria exchange small molecules.

“Many bacteria species are known to communicate by a mechanism known as quorum sensing, that is, relaying between them small molecules to trigger various behaviors,” said Hasty. “Other bacteria are known to disrupt this communication mechanism by degrading these relay molecules.”

Taking these communication elements from different organisms, Hasty and his team of researchers — who included UCSD bioengineering graduate students Tal Danino and Octavio Mondragon — designed and constructed a network in the genetic model bacterium E. coli with positive and negative feedback components to produce a colony of synchronized clocks.

Hasty said the architecture of the circuit is similar to his team’s previous genetic clock (see: here), but with the quorum sensing components allowing the phase information — that is, the oscillations between the bacterial cells — to be relayed.

The researchers constructed devices to precisely control the sizes of the bacterial colonies between two different scales: a micron, or a millionth of a meter, and a millimeter, or one-thousandth of a meter. At the micron scales, Hasty said the cells in the colonies oscillate synchronously from 50 to 90 minutes, a period that can be tuned externally. But at the longer, or millimeter scales, he noted, the time for diffusion of the signal becomes more important, allowing the researchers to actually observe the propagation of the signal through the colony.

“The use of quorum sensing is a promising approach to increase the sensitivity and robustness of the dynamic response to external signals,” said Hasty. “In nature, synchronization typically helps stabilize a desired behavior arising from a network of intrinsically noisy and unreliable elements. We think the synchronized genetic clock sets the stage for the use of microbes as a macroscopic biosensor with oscillatory output, or applications of using a synchronized periodic signal in drug delivery.”

The scientists received funding for their development from the National Institute of General Medical Sciences, which is part of the National Institutes of Health.

American astronomer and astrophysicist Frank Drake devised his namesake equation in the early 1960s.

The 31-year-old Backus — who lives on a narrow boat in central London — is not even that particular about his ideal match, requiring only that she be a London-based female, aged 24-34, with a university education.

“I am not trying to be an elitist or anything,” he said about his educational requirements. “Everyone has preferences. I just think we would have more in common.”

Further reducing his chances, he has estimated he would be physically attracted to just five percent of the women meeting all these criteria.

This means there are about 10,500 women in Britain who tick all the boxes for Backus, he said — just above the 10,000 potential communicative civilizations that could exist in the Milky Way according to the Drake equation.

So just 0.14 percent of Londoners and 0.017 percent of the British population meet Backus’s own requirements, he said.

But a relationship takes two.

If this economist’s dream women are equally as fussy as he is, his chances of finding someone who will return his affections plummets to just 0.00034 percent, he said.

“There are 26 women in the UK with whom I might have a wonderful relationship. So, on a given night out in London there is a 0.00034 percent chance of meeting one of these special people,” he said.

“That’s a 1 in 285,000 chance. Not great.”

But love can still defy the odds right on your doorstep. Since writing his paper on the equations of finding love, Backus has started dating his neighbor Rose. She meets his age requirement, has a university degree and also lives on a boat.

The material contains cobalt atoms arranged in long chains and each atom acts like a tiny bar magnet that can point either ‘up’ or ‘down’.

When a magnetic field is applied at right angles to the aligned spin directions, the spins can ‘quantum tunnel’ between the ‘up’ and ‘down’ orientations. At a precise value of the applied field these fluctuations ‘melt’ the ferromagnetic order of the material resulting in a ‘quantum critical’ state.

‘You might expect to see random fluctuations of the spins at this critical point but what we uncovered was a remarkable structure in the resonances of the magnetic spins indicating a perfectly harmonious state,’ said Radu Coldea from Oxford University’s Department of Physics who led the team.

As the critical state was approached the researchers observed that the chain of atoms behaved like a ‘magnetic guitar string’.

Radu added: ‘The tension comes from the interaction between spins causing them to magnetically resonate. We found a series of resonant modes. Close to the critical field the two lowest resonant frequencies approached closely the golden ratio 1.618…, a characteristic signature of the predicted E8 symmetry.’

He is convinced that this is no coincidence and it reflects a subtle form of order present in the quantum system.

The resonant states seen experimentally in cobalt niobate may be our first glimpse of complex symmetries that can occur in the quantum world. “The results suggest that similar ‘hidden’ symmetries may also govern the physics of other materials near quantum critical points where electrons organize themselves according to quantum rules for strong interactions,’ Radu told us.

The research was supported by EPSRC and Radu aims to use a new EPSRC grant to explore the physics of materials near quantum criticality.

The team included Dr Radu Coldea, Dr Elisa Wheeler and Dr D Prabhakaran from Oxford University’s Department of Physics, as well as researchers from Helmholtz Zentrum Berlin, ISIS Rutherford Laboratory, and Bristol University.