Here's an interesting example of emergent properties.

In short, it's essentially a topology-based approach to solving a classical optimization problem. Quite novel, really, though it's not clear if the solution offers a whole lot of benefit over brute force calculation in terms of saved computation time. The paper is here.

What struck me as particularly interesting was the authors' proposal to physically implement their "blob" model:

...it would be satisfying if this virtual material could be implemented and embodied in a real physical substrate with the desired physical (for example visco-elastic, free energy minimisation) properties.

What would this accomplish? I'm not saying that it wouldn't be a neat, cheap engineering project to build an elastic blob capable of solving traveling salesman problems, it just doesn't seem like any kind of a job for real-world models.

Jeff Jones, & Andrew Adamatzky (2013). Computation of the Travelling Salesman Problem by a Shrinking Blob arXiv arXiv: 1303.4969v2

Here's a paper dealing with a frequently worrisome issue:

Shrestha, P. M., Nevin, K. P., Shrestha, M., & Lovley, D. R. (2013). When Is a Microbial Culture “Pure”? Persistent Cryptic Contaminant Escapes Detection Even with Deep Genome Sequencing. mBio, 4(2). doi:10.1128/mBio.00591-12
Microbiologists, like most biologists, like to have neatly organized categories and taxonomies available at all times. We work with individual species, specific strains of those species, and often mutants of those strains. If we grow our chosen organisms and they don't behave as expected, we generally assume that contamination occurred somewhere along the line or that a new mutation transpired. The usual preventative measure is simply to ensure that cultures start from single cells of the desired strain.

Shrestha et al. seem to have had some issues with culture contamination. This group works with Geobacter sulfurreducens strain DL1 in studies of microbial fuel cells. As they were attempting to isolate G. sulfurreducens strains with mutations enabling them to be more electrically conductive, they managed to isolate a strain later named KN400. This strain was great at conducting current but clearly wasn't just a mutant of DL1: sequencing showed that the new strain likely differed by more than 27,000 SNP's, or far more mutations than any lab-based methods of selection were likely to create.

The authors sought to clarify the origins of G. sulfurreducens strain KN400. Next-gen sequencing showed that a sequence specific to KN400 could be found in the original DL1 cultures, though out of more than 10⁷ sequence copies, fewer than 300 were the KN400 sequence. The new strain wasn't a new mutant at all. Subsequent growth studies found that even repeated rounds of restreaking cells on solid medium still yielded colonies with minute but detectable levels of the cryptic KN400 strain. Shrestha et al. suggest that their intense electrical conductivity-based selective pressures may have been the only reason they were able to isolate KN400 at all.

It's still not clear how G. sulfurreducens KN400 lives alongside the DL1 strain so well. My guess is that KN400 is actually an instance of a separate but phylogenetically related chromosome copy acting as a mobile genetic element. Cultures of the DL1 strain consistently maintain KN400 cells at low levels, so some variety of fitness benefit must be conferred to the entire culture or we'd expect the minority cells to just get selected against. There's clearly something strange going on with this bacterial species but it may be an ongoing process.

It was my birthday this past weekend! Danielle made a lovely cake:

You got your chocolate in my peanut butter, intentionally.

and a lovely phage:

Not pictured: crocheted phage in lysogenic state.

It also seemed like an appropriate time for this:

A birthday cake is no place for a cow.

Gatsogiannis, C., Lang, A. E., Meusch, D., Pfaumann, V., Hofnagel, O., Benz, R., Aktories, K., et al. (2013). A syringe-like injection mechanism in Photorhabdus luminescens toxins. Nature, advance on. Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved. doi:10.1038/nature11987

Didn't read this one yet, but the abstract contains the phrase "vuvuzela-shaped channel" so it should be interesting.

Glud, R. N., Wenzhöfer, F., Middelboe, M., Oguri, K., Turnewitsch, R., Canfield, D. E., & Kitazato, H. (2013). High rates of microbial carbon turnover in sediments in the deepest oceanic trench on Earth. Nature Geoscience, advance on. Nature Publishing Group. doi:10.1038/ngeo1773.

This is a small letter about Challenger Deep, the deepest point in Earth's oceans. Located within the southern extent of the Mariana Trench, this spot is nearly 11,000 meters deep. It's pretty chilly down there - about 2.5 degrees C - but more importantly it's under extremely high pressure. Wikipedia tells me it's more than 16,000 psi or about 1,099 times surface pressure. This doesn't stop bacterial growth: Glud et al. found that two sediment samples from this deep spot contained, on average, nearly 10⁷ prokaryotic cells per cubic centimeter. Shallower sites nearby were also dense with microbial life but not nearly as rich as the Challenger Deep samples. 

Glud et al. suggest that deep-sea trenches like the Mariana may serve to naturally funnel fresh sediment downward, providing essential nutrients for microbial growth at extreme depths. Further analysis of these deep-sea microbes could show how they've adapted to such specialized metabolic demands.