As always, there was a fair amount of speculation revolving around the 2013 Science Nobels. In physics, it was more or less a given that the award would involve the Higgs boson. However, there were multiple contributors and the award can only be split three ways. It can also only be given for experimentally verified results.
The elusive particle and its associated field, together offer a (relatively) simple explanation for the existence of mass in the so-called Standard Model. The particle was postulated simultaneously in 1964 in three papers, showcasing the efforts of six physicists. Peter Higgs released a seminal paper working alone - he also hypothesised the Higgs Field. Francois Englert and Robert Brout collaborated to produce very similar predictions. Gerald Gulanik, Carl Hagen & Tom Kibble also released a key paper that completed the theoretical description. Brout has since passed away but Gulanik, Hagen and Kibble are still very much around.
The Committee chose to honour Englert and Higgs while overlooking the contributions of the trio. It also bypassed the European Organisation for Nuclear Research (CERN) teams that proved the existence of the boson. The particle's existence was confirmed on 4 July 2012, by two teams working on data from the Large Hadron Collider. Each team included over 3,000 scientists.
The Peace Prize has often been awarded to groups such as Amnesty International, the Red Cross and this year, to the Organisation for the Prohibition of Chemical Weapons. The scientific community wondered if the Committee would stretch the rules to include CERN.
The chemistry prize went to the trio of Martin Karplus, Michael Levitt, and Arieh Warshel. The citation was for "the development of multi-scale models for complex chemical systems". The trio worked together in the 1970s to find ways to model chemical reactions on computers and they found a way to wed two very different approaches.
Classical Newtonian physics allows for simple computations to model macroscopic masses. But classical physics cannot tackle chemical reactions. Quantum methods can in theory, model chemical reactions but the calculations require massive number-crunching power.
Back in 1972, when computers were pitifully underpowered, this team found ways to fuse the two approaches. They saw a way to calculate reactions using quantum physics at the single electron-level. Then they incorporated the results into a less maths-intensive classical model to build a picture at the molecular level. They scaled this work up and modified it to model enzymatic reactions a couple of years later.
The fine-tuning of these methods has continued. Given Moore's Law, where processing power has increased vastly, these methods can now be used to model highly complex reactions with extreme accuracy and in great detail. Potential new drugs for instance, are always modelled on computers to judge likely effects, prior to actually being developed in the lab. Complicated devices such as catalytic converters for internal combustion engines are also modelled before development. This saves a lot of time and expense.
The Nobel for Medicine or Physiology was awarded to James E Rothman, Randy W Schekman and Thomas C Südhof for their "discoveries of the machinery regulating vesicle traffic, a major transport system in our cells".
Each living cell can be viewed as a sort of factory that produces, absorbs and exports molecules. For example, insulin, cytokines, neuro-transmitters, etc, are all produced and released into the blood. These cellular products are moved around in small bubble-like packets called vesicles. Vesicles deliver the molecules where they are required, fusing with cells to receive and release molecules.
The three scientists discovered the principles that govern this transport mechanism to ensure that the right products are delivered to the right place at the right time. Schekman discovered the genes responsible for managing vesicle traffic. Rothman worked out how vesicles used proteins to fuse with cells to transfer cargo. Südhof deciphered the signalling mechanism that tells vesicles what to deliver, where and when.
Schekman started studying the genetic basis of vesicles using yeast. He managed to isolate yeast cells with defective transport machinery and then identified the mutated genes responsible for the problems. Schekman identified three classes of genes that control different facets of the transport system.
More than a decade later, Rothman was studying vesicle transport in mammalian cells in the 1980s. He discovered that a protein complex enables vesicles to dock and fuse with the targeted cell membranes, almost as though vesicles use a biological zipper. There are many such binding proteins but they bind only in specific combinations to ensure that the cargo is delivered to precise locations.
Südhof, meanwhile, was investigating how nerve cells communicate with each other in the brain. The signalling molecules, or neurotransmitters, are released from vesicles that fuse with the outer membrane of nerve cells. These vesicles only release their contents when the nerve cell signals to its neighbours. Calcium ions were believed to be involved in the signalling. In the 1990s, Südhof tracked calcium sensitive proteins in nerve cells and identified the machinery that responds to an influx of calcium ions by releasing cargo. This explained how precise timing was achieved and controlled biologically.
It transpired that some of the genes Schekman had discovered in yeast corresponded to those Rothman identified in mammals. Amazingly, vesicle mechanisms operate with the same general principles in organisms as different as yeast and man, suggesting this is a very evolutionary development. Defective vesicle transport occurs in a variety of diseases including many neurological and immunological disorders, as well as diabetes. Decoding the transport mechanism has helped substantially in an understanding of such disorders.
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