Nanotechnology Used To Find Marjorana Fermion

Researchers at TU Delft’s Kavli Institute and the Foundation for Fundamental Research on Matter (FOM Foundation) have succeeded for the first time in detecting the Majorana particle. In the 1930s, the brilliant Italian physicist Ettore Majorana reasoned from quantum theory the possibility of the existence of a very special particle, a particle that is its own anti-particle: the Majorana fermion. The ‘Majorana’ borders between matter and anti-matter.

The Italian physicist Ettore Majorana was a brilliant theorist who showed great insight into physics at a young age. He discovered a hitherto unknown solution to the equations from which quantum scientists deduce elementary particles: the Majorana fermion. Practically all theoretic particles that are predicted by quantum theory have been found in the last decades, with just a few exceptions, including the enigmatic Majorana particle and the well-known Higgs Boson.

Nanoscientist Leo Kouwenhoven already caused great excitement among scientists in February by presenting the preliminary results at a scientific congress. On 12 April, the scientists published their research in Science.

Majorana fermions are very interesting – not only because their discovery opens up a new and uncharted chapter of fundamental physics, but they may also play a role in cosmology.

A proposed theory assumes that the mysterious dark matter, which forms the greatest part of the universe, is composed of Majorana fermions. Furthermore, scientists view the particles as potential building blocks for a quantum computer. Such a computer would be far more powerful than the best supercomputer, but only functionally exists in theory so far (or until very recently). Contrary to an ‘ordinary’ quantum computer, a quantum computer based on Majorana fermions is exceptionally stable and barely sensitive to external influences.

For the first time, scientists in Leo Kouwenhoven’s research group managed to create a nanoscale electronic device in which a pair of Majorana fermions ‘appear’ at either end of a nanowire. They did this by combining an extremely small nanowire, made by colleagues from Eindhoven University of Technology, with a superconducting material and a strong magnetic field. ‘The measurements of the particle at the ends of the nanowire cannot otherwise be explained than through the presence of a pair of Majorana fermions’, says Leo Kouwenhoven.

It is theoretically possible to detect a Majorana fermion with a particle accelerator such as Large Hadron Collider at CERN. The current Large Hadron Collider appears to be insufficiently sensitive for that purpose but, according to physicists, there is another possibility: Majorana fermions can also appear in properly designed nanostructures.

"What’s magical about quantum mechanics is that a Majorana particle created in this way is similar to the ones that may be observed in a particle accelerator, although that is very difficult to comprehend", explains Kouwenhoven.

"In 2010, two different groups of theorists came up with a solution using nanowires, superconductors and a strong magnetic field. We happened to be very familiar with those ingredients here at TU Delft through earlier research." Microsoft approached Leo Kouwenhoven to help them lead a special FOM programme in search of Majorana fermions, resulting in a successful outcome.

Artificial DNA Called XNA May Create Synthetic Life

Researchers moved a step closer to creating new life forms in the laboratory after they demonstrated an artificial genetic material called XNA can be replicated in the test tube much like real DNA. X, which in this case stands for "xeno" indicates the replacement of the helical backbone of the new molecule.

Scientists at the Medical Research Council Laboratory of Molecular Biology in the U.K. demonstrated for the first time a way to extract information from the artificial genetic molecules and mass produce copies of them.

The research, published today in the journal Science, shows that DNA and its sister molecule RNA may not be the only chemical structures upon which a living unit can be based.

“Life is based on this amazing ability of DNA and RNA to store and propagate information,” said Philipp Holliger, a Medical Research Council molecular biologist and senior author on the study. “We have shown that the basic functions of DNA and RNA can be recapitulated” with new artificial molecules.

Vitor Pinheiro and colleagues from Philipp's group used sophisticated protein engineering techniques to adapt enzymes, that in nature synthesise and replicate DNA, to establish six new genetic systems based on synthetic nucleic acids. These have the same bases as DNA but the ribose linkage between them is replaced by quite different structures.

In doing this they showed that there is no functional imperative limiting genetic information storage to RNA and DNA. Therefore, the discovery has implications for the understanding of life on Earth.  As other informational molecules can be robustly synthesised and replicated, the emergence of life on Earth is likely to reflect the abundance of RNA (and DNA) precursors in early Earth.

The scientists invented a lab method for making copies of synthetic DNA. They also developed a way to make XNA fragments that evolve with desired properties.


The work may give scientists a new method for creating designer drugs and diagnostic tools. “There are a whole host of opportunities in biotechnology which now become possible,” Holliger said. In particular, they created XNA fragments that could bind with great specificity to a molecular target in the HIV virus.

XNA-based drugs “might have a future to rival antibodies,” he said. Antibody drugs, such as Roche Holding AG (ROG)’s Avastin for cancer and Abbott Laboratories’ (ABT) Humira for autoimmune diseases, have become some of the biggest selling therapies in recent years.

DNA, deoxyribonucleic acid, is the hereditary molecule at the center of our cells. It contains code, in the form of chemical letters A, T, C and G, that tells the body how to make proteins that perform numerous bodily functions such as regulating blood sugar or fighting infections.

For medical use, the development of functional nucleic acids, called aptamers, with diagnostic, therapeutic and analytical applications. Aptamers can have a number of significant advantages over the current small molecule and antibody-based therapies. For example, they bind their target molecule with high specificity (like antibodies) but being smaller they are expected to have better tissue penetration. They have low-toxicity and low-immunogenicity and they can be chemically modified to improve their stability and pharmacokinetic properties.

XNAs, or xeno-nucleic acids, maintain the same four-letter chemical code while altering the backbone of the DNA “double helix” molecule to add properties such as acid resistance.

“It’s a breakthrough,” said Gerald Joyce of The Scripps Research Institute in La Jolla, California, who was not involved in the study—“a beautiful paper in the realm of synthetic biology.”

While researchers have been working for years on therapies based on DNA and RNA, a limitation is that the nucleic acids break down easily in the body, and need to be modified to make them more stable, said Joyce.

One limitation of the new method is that it isn’t entirely artificial, and natural DNA is still required as an intermediate step in the XNA copying process.

The XNA work provides a new way of developing designer nucleic acid drugs that could resist breakdown, or have other desirable properties, such as the ability to slip from the bloodstream into diseased cells, said Holliger.

It also could help drug researchers working on so-called small interfering RNAs, he said. Companies working on such drugs include Alnylam Pharmaceuticals Inc. (ALNY) in Cambridge, Massachusetts. RNA is a similar molecule to DNA that transports genetic information from the cell nucleus to the molecular factories where proteins are made.

In the field of synthetic biology, this represents a breakthrough, and might change our understanding of life itself.  The implications of the study will likely prove to be vast for a multitude of fields of study.

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Baboons Learn Word Recognition

Scientists report that they trained six Guinea baboons (Papio papio) to distinguish real, four-letter English words such as "done" and "vast" from non-words such as "dran" and "lons." After six weeks, the baboons learned to pick out dozens of words — as many as 308 in the case of the clever Dan, and 81 for Violette — from a sea of 7,832 non-words.

The study was published in Nature.

Each of the monkeys performed significantly better than 50 percent, which they would have scored by randomly guessing which letters formed words or non-words. They averaged almost 75 percent right, with some scoring 90.

The study is "extraordinarily exciting," said cognitive psychologist Stanislas Dehaene of the College de France in Paris, an expert on the neural basis of reading who was not involved in the research, and author of, Reading in the Brain: The New Science of How We Read. "For the first time, we have an animal model of a key component of literacy, the recognition of the visual word form."

The study was intended less to probe animal intelligence than to explore how a brain might learn to read. It suggests that, contrary to prevailing theory, a brain can take the first steps toward reading without having language, since baboons don't.  A similar hypothesis has been put forward by Dr. Robert Titzer, developer of the Your Baby Can Read: Early Language Development System system, that uses the pattern recognition ability of infants and toddlers as a base to learn word recognition, and accelerate reading in children.

"Their results suggest that the basic biological mechanisms required for reading have deeper evolutionary roots than anyone thought," said neuroscientist Michael Platt of Duke University, who co-authored an analysis of the study. "That suggests that reading draws on much older neurological mechanisms" and that apes or monkeys are the place to look for them.

Reading has long puzzled neuroscientists. Once some humans started doing it (about 5,000 years ago in the Middle East), reading spread across the ancient world so quickly that it cannot have required genetic changes and entirely new brain circuitry. Those don't evolve quickly enough. Instead, its rapid spread suggests that reading co-opted existing neural structures.

To be sure, other animals have learned to recognize letters. In a 1982 experiment, for instance, pigeons were able to identify all 26 letters of the English alphabet.

But the baboons were not simply memorizing which strings of letters were words, said Grainger. When shown a word for the first time, they identified it correctly about 70 percent of the time, suggesting the animals were applying the statistical rules they had inferred.

The word-savvy baboons may be drawing on "more generalized learning mechanisms and visual processing abilities rather than specialized mechanisms unique to humans," said Diana Reiss of Hunter College in New York, who has done pioneering work in animal intelligence.

A prime candidate for those processing abilities lies in a region of the brain that becomes active when people read. Discovered by Dehaene, it is called the "visual word form area" and is located behind the left ear. It recognizes strings of letters, and the more active it is in 7- to-18-year-olds, studies show, the better readers they tend to be.

"Neuroimaging shows that this region is specific for words and not meaningless strings of letters," said Duke's Platt.

Since reading arrived on the scene a mere blink of the eye ago, evolutionarily speaking, the visual word form area cannot have developed in order to support reading. If baboons or human ancestors also had this structure, the question becomes what they used it for. Best guess: recognizing objects by visually assembling their parts, such as tall cylinder + bushy top = tree.

Among the many surprises in the study is that it involved baboons rather than a primate known for braininess.

"Guinea baboons have a lot of social savvy, since they have to learn about complex male-male and male-female interactions in their troop," said primate curator Craig Demitros of the Brookfield Zoo outside Chicago. "They're smart, but not at the level of chimps."

Apart from the glimpses it provides into the evolution of the brain's ability to read, the study has implications for education. "You might conclude that phonics doesn't work" as well as teaching children to read by recognizing the entire word, said Platt. "This study suggests that reading is all about pattern recognition and not working out phonemes."

The team next plans to try to teach the baboons an artificial alphabet. This would give greater control over the visual information that defines individual letters, Grainger explains, and would provide a more precise idea of how baboons master word recognition.

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