Just three articles for this month.

• This is an amusing article that appeared in The Economist. It’s about research that demonstrates that dogs have lateralized brains, meaning that the left and right sides of their brains work differently. The specific claim is that dogs wag their tails to the right when they encounter something that they like, which should be interpreted as a friendly greeting and to the left when in the presence of potential threats, which could be interpreted as a warning. Not only was this difference in behaviour observed under controlled conditions, but measurements of anxiety levels also correlated with this finding. As you might expect, I immediately tried to note if I could detect such differences in behaviour in my own dogs but I must report failure. It is simply too difficult to consistently determine which side a dog is wagging the tail towards.
• The next article is from the MIT Technology Review and talks about how quantum mechanical effects come into play in photosynthesis, or light harvesting, as this article seems to want to call it. Specifically this article covers the transformation of light into chemical energy inside the reaction centres of pigment proteins in green sulfur bacteria. The interesting part is that the transformation cannot occur under classical physics because it would take too long for the light to find the reaction centre by randomly bouncing around inside the protein network. So instead, the light travels a variety of routes through the network at the same time and the superposition collapses at just the right time to deposit the energy at the reaction centre, which is why the process is so energy efficient.
• Finally, here’s a great feature article on the origins of umami from Smithsonian.com. As the article points out umami is chemically very similar to the sodium salt of glutamic acid, better known today as monosodium glutamate. However while MSG has a terrible reputation among the health conscious, most people do not seem to regard umami in the same way. The article also points out that the poor reputation of MSG is probably undeserved. While people can be allergic to MSG, and these people should certainly avoid it, studies have failed to consistently find evidence of deleterious effects and the consensus today is that it is generally safe despite early results indicating that it may cause brain lesions. The article even goes on to suggest that its poor reputation may be linked to racism since many people in the United States first came to know of MSG due to its prevalent use in Chinese restaurants.

Here’s the October 2013 instalment of my regular feature:

•  Recently a lot of attention was paid to news about a new breakthrough towards the treatment of Alzheimer’s disease. Rather than link to the more mainstream accounts of the research involved however, here is a fairly detailed explanation of what was actually discovered. The idea is that when brain cells are invaded by a virus, misfolded prion proteins build up causing a defence mechanism to kick in that dramatically reduces the production of new proteins. But in the case of prion diseases, this backfires and actually causes even more misfolded prion proteins to accumulate. The new research then covers the usage of a new molecule that inhibits this defence mechanism, called unfolded protein response. In trials involving mice, they found that by the time all of the untreated infected mice reached critical stages of disease, the treated ones were still free of symptoms. Unfortunately as this blog post points out, the mice were not monitored for longer than that because the treated mice developed prediabetic symptoms that included increased blood glucose and weight loss. Animal welfare rules in the institution required that these mice be sacrificed rather than prolong the study, so it is unknown if the drug can successfully prevent the development of prion disease for a longer period than what was observed and it is equally unclear that it is even possible to develop a viable treatment without such debilitating side effects. Personally, I find this blog post especially interesting as an example of how to look past at the hype and exaggerations in the mainstream media that initially reported and actually look at the real facts.
• Next here’s a lighter piece about the discovery of a so-called free-floating planet in space, that is a planet-sized object that is not a star and yet does not seem to orbit any star. The object which has been dubbed PSO J318.5-22 is located about 80 light years from Earth (which is probably why we were able to detect it given its cool temperature) and has a mass of six times that of Jupiter. Large for a planet, but far too small to be a star. It is the only such object found so far.
• This article talks about how a team managed to get photons to interact with each other, a feat that has not previously been achieved. Essentially they fired single photons into a cloud of extremely cold rubidium atoms. As the photons move through the cloud, it excites the rubidium atoms causing the photon itself to lose energy and slow down. The team then found that two photons that were fired into the cloud, exited the medium together as a single bound molecule, representing a new form of matter that has been theorized to exist but never before observed.

I’ve been doing this summary of the Nobel Prizes since 2010. I’m late this year due to vacationing in Greece (more on that later) but here is this year’s round up, better late than never I suppose.

This year the physics prize goes to François Englert and Peter W. Higgs for independently proposing the theory of how particles acquire mass in 1964. This theory involves the existence of a special kind of particle, now known as the Higgs boson. This award is especially delightful for me, having recently worked through the From the Big Bang to Dark Energy course on Coursera which spent considerable time on the subject. This theory filled a hole in the Standard Model of physics because without mass, matter would collapse as electrons dispersed from atoms at light speed, yet some particles, such as photons, must remain massless for the Standard Model to hold. The Higgs field then breaks the symmetry, allowing some particles which do not interact with the Higgs field to remain massless, while those that do, gain mass.

The award was prompted by news this year that CERN’s Large Hadron Collider had found the proposed particle at an energy level of 125 GeV, about a hundred times heavier than a proton, definitively proving the correctness of their theory.

The chemistry award goes to Martin Karplus, Michael Levitt and Arieh Warshel for developing innovative techniques to simulate models of chemical reactions on a computer. Previously scientists had to choose between modelling chemical reactions in terms of classical physics or in terms of quantum mechanics. The former method allowed scientists to calculate and model large chemical molecules but since molecules are excited and become filled with energy during chemical reactions, the classical systems cannot simulate them as they have no understanding of the energy state of molecules. Quantum mechanical models do allow scientists to simulate reactions but they require enormous amounts of computing power such that scientists were restricted to only very small molecules.

This new system, published as the first computerized model of an enzymatic reaction in 1976, married the best of both worlds. Quantum physical calculations are used on the electrons and atomic nuclei that are directly involved in the reaction being studied but classical equations are used to model the other parts of the molecule. This allows scientists to model even the chemical reactions of large molecules today.

The medicine award goes to James E. Rothman, Randy W. Schekman and Thomas C. Südhof for working out precisely how the transportation system inside cells work. This is based around vesicles, miniature, bubble-like structures inside cells, that shuttle cargo between the different organelles of the cell or fuse with the outer membrane of the cell to deliver cargo outside of the cell. Working separately, the three scientists unravelled different parts of the system between the 1970s and the 1990s.

One of them found how genes contributed to the different facets of the vesicle system. Another discovered that proteins on the vesicles and target membranes fitted each other uniquely like two sides of a zipper, ensuring that the correct molecules would be delivered to the correct location and that the genes previously discovered coded for these proteins. The third identified molecular machinery in cells which responds to an influx of calcium ions and then directs neighboring proteins to bind vesicles to the outer membrane of the nerve cell, allowing neurotransmitter signalling substances to be released and explaining how nerve cells communicate with one another.

Finally the economics prize is awarded to Eugene F. Fama, Lars Peter Hansen and Robert J. Shiller for their contributions to the study of asset prices. These studies spanning the 1960s to the 1980s, first established that stock prices are indeed extremely difficult to predict in the short run and that new information is incorporated very quickly in market prices. Yet paradoxically, in the longer run, they are easier to predict as the stock’s value corresponds well to the expected value of future dividends. It was further found, using a new statistical method, that the well-known Consumption Capital Asset Pricing Model (CCAPM) widely used in the 1970s could not match the wide fluctuations of asset prices, prompting extensions to the model.

These findings are currently foundational to the study of asset prices in both academic research and market practice. One result is the emergence of index funds in stock markets all over the world. Another is the development of the Case-Schiller housing price index which helps gauge trends in housing prices.

It’s time for our monthly round up of interesting science stuff. It’s a pretty thin month unfortunately:

• Let’s start with a fairly arcane article. It’s from Quanta Magazine and is about the discovery of a geometric construct that is called the amplituhedron. According to physicists, its discovery vastly simplifies the calculation of particle interactions. Along the way however, it does away with locality, which says that particles interact at specific points in space-time, and unitarity, which says that the sum of all quantum mechanical probabilities add up to 1. These are fundamental concepts in current quantum field theory and this discovery not only undermines these assumptions, but challenges the notion that space and time are fundamental constituents of nature. It suggests that space and time are emergent properties instead.
• Next is a link to the actual research paper, which makes for rather heavy reading. It appears in PLOS ONE and is about orangutans may have better abilities to plan for the future than anyone ever suspected. It seems that when male orangutans travel long distances, they emit long calls which are used to communicate with other orangutans, and specifically may attract female orangutans and repel male rivals. The researchers found that the direction of the long calls emitted at dusk corresponded well with the direction that the orangutan chooses to travel in on the next day, suggesting that the animal is mentally capable of planning out its trip well beforehand and acting out on its plans.
• Finally here’s a link that’s been going out to everyone interested in science. It appears in the Smithsonian and is about the discovery of the first and so far only functional gearing system found in nature. The gears were found in a species of long hopping insects. The gears lock their back legs together, allowing the two legs to swing at the precise same moment so that the insect jumps forward. It seems that this wasn’t discovered earlier because the system exists only in juveniles of the species as adults fail to regrow the gears as their skin molts away. The speculation is that the gears are too fine and fragile a structure to repeatedly regrow and even a single broken gear tooth would render the system useless.