DNA and RNA are the fundamental biological blueprints for all known life of Earth, capable of storing information, evolving and helping cells to manufacture proteins. But now researchers at the MRC Laboratory of Molecular Biology, in Cambridge, have created alternative genetic polymers called xeno-nucleic acids or XNA’s by replacing the d (deoxyribose) or r (ribose) for other molecules. The XNA’s produced in the lab were shown to exhibit similar behaviour and were more stable compared with their natural counterparts. The research reported today in Science could help scientists develop new forms of synthetic life, improve medicines and advance biotechnology. It also indicates that other life forms existing elsewhere with a completely different chemistry may also be driven by evolution.
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DNA and RNA are the fundamental biological blueprints for all known life of Earth, capable of storing information, evolving and helping cells to manufacture proteins. But now researchers at the MRC Laboratory of Molecular Biology, in Cambridge, have created alternative genetic polymers called xeno-nucleic acids or XNA’s by replacing the d (deoxyribose) or r (ribose) for other molecules. The XNA’s produced in the lab were shown to exhibit similar behaviour and were more stable compared with their natural counterparts. The research reported today in Science could help scientists develop new forms of synthetic life, improve medicines and advance biotechnology. It also indicates that other life forms existing elsewhere with a completely different chemistry may also be driven by evolution.

Source: sciencemag.org

Your bathroom scale can easily tell you whether you lost those couple of kilograms, but will definitely not notice whether you trimmed your fingernails or had your hair cut. Not only do the relatively rudimentary mechanisms of ordinary scales limit the measurement precision, but they also make the accuracy of the order of some dozen grams—not enough to notice minute differences in weight. Measuring smaller and smaller masses, such as those of microscopic object or even molecules, require scales with fantastically high degrees and precision and accuracy that the weighing scales we are used to can’t obviously provide. By using the now seemingly ubiquitous carbon nanotubes researchers at the Catalan Institute of Nanotechnology in Spain created a scale with an accuracy of 10−24 grams (called a yoctogram) that makes it able to potentially measure the mass of an atom down to the last proton. The nanotubes vibrate at different frequencies, depending on the mass of the particles or compounds deposited on them. By measuring these frequencies it is then possible to infer with the highest sensitivity ever achieved the mass of the tiny objects to be weighed. It is like listening to the note produced by a guitar string that vibrates when plucked, and comparing it to the different note that it produces when some object—a little ball of Play-Doh, for instance—is attached to the string. By comparing the two notes, one could know the mass of the Play-Doh sitting on the string. Chaste et al., “A nanomechanical mass sensor with yoctogram resolution”, Nature Nanotechnology (2012) Image: Bundles of carbon nanotubes (Wikipedia)
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Your bathroom scale can easily tell you whether you lost those couple of kilograms, but will definitely not notice whether you trimmed your fingernails or had your hair cut. Not only do the relatively rudimentary mechanisms of ordinary scales limit the measurement precision, but they also make the accuracy of the order of some dozen grams—not enough to notice minute differences in weight. Measuring smaller and smaller masses, such as those of microscopic object or even molecules, require scales with fantastically high degrees and precision and accuracy that the weighing scales we are used to can’t obviously provide. By using the now seemingly ubiquitous carbon nanotubes researchers at the Catalan Institute of Nanotechnology in Spain created a scale with an accuracy of 10−24 grams (called a yoctogram) that makes it able to potentially measure the mass of an atom down to the last proton. The nanotubes vibrate at different frequencies, depending on the mass of the particles or compounds deposited on them. By measuring these frequencies it is then possible to infer with the highest sensitivity ever achieved the mass of the tiny objects to be weighed. It is like listening to the note produced by a guitar string that vibrates when plucked, and comparing it to the different note that it produces when some object—a little ball of Play-Doh, for instance—is attached to the string. By comparing the two notes, one could know the mass of the Play-Doh sitting on the string.

Chaste et al., “A nanomechanical mass sensor with yoctogram resolution”, Nature Nanotechnology (2012)

Image: Bundles of carbon nanotubes (Wikipedia)

A building is a complicated entity. Many elementary blocks, such as bricks and concrete pillars, are put together and made to interact in simple ways to produce the final structure. If interacting in varied manners, however, objects apparently as basic as bricks, concrete and mortar can produce interesting collective behaviours. The workings of the resulting systems, of which ant colonies and city traffic are excellent examples, often cannot be traced back to their constituents but arise instead from the complex interactions between them. Researchers at MIT’s Computer Science and Artificial Intelligence Laboratory Objects have been building tiny cubes—some 10 millimeters wide—with magnets on their faces that can be switched on and off by a rudimentary microprocessor contained within the cube itself. Each cube, rather unintelligent in itself and of limited capabilities, can be programmed to interact with many other such cubes by means of its magnets, following complex sets of rules. This kind of technology, which combines modular robotics, nanotechnology and computer science, is also known as claytronics and was pioneered by a collaboration between Carnegie Mellon and Intel. Building smaller and smaller smart cubes and designing more efficient algorithms may one day lead to self-assembling macroscopic objects—like a sand castle that puts itself together on account of whatever rules have been programmed in each of its grains of sand.
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A building is a complicated entity. Many elementary blocks, such as bricks and concrete pillars, are put together and made to interact in simple ways to produce the final structure. If interacting in varied manners, however, objects apparently as basic as bricks, concrete and mortar can produce interesting collective behaviours. The workings of the resulting systems, of which ant colonies and city traffic are excellent examples, often cannot be traced back to their constituents but arise instead from the complex interactions between them. Researchers at MIT’s Computer Science and Artificial Intelligence Laboratory Objects have been building tiny cubes—some 10 millimeters wide—with magnets on their faces that can be switched on and off by a rudimentary microprocessor contained within the cube itself. Each cube, rather unintelligent in itself and of limited capabilities, can be programmed to interact with many other such cubes by means of its magnets, following complex sets of rules. This kind of technology, which combines modular robotics, nanotechnology and computer science, is also known as claytronics and was pioneered by a collaboration between Carnegie Mellon and Intel. Building smaller and smaller smart cubes and designing more efficient algorithms may one day lead to self-assembling macroscopic objects—like a sand castle that puts itself together on account of whatever rules have been programmed in each of its grains of sand.

Source: web.mit.edu

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  • It's Not My Field #5: Frank Close

The infinity puzzle. In this episode we interview Frank Close, professor of physics at the University of Oxford and author of the book The Infinity Puzzle. We discussed with him the public perception of modern physics, who should be awarded Nobel prizes and what sort of scientific questions are the right ones.
Visit our SoundCloud page to download the episode.

“The people who have missed out on Nobel prizes but were very near to getting one, they are known in the field but they are not known to the general public. […] The stories of the winners are very well-known, and I am sure that there are stories that are not told by many people who are in the running who do not get one and keep the secret to themselves.”

We thank Frank Close and the School of Physics and Astronomy of the University of Glasgow.
This episode includes a CC-licensed Freesound.org sound sample by user Setuniman.

Source: SoundCloud / ScientificBritain

Cryptography is the science of secure communications in the presence of unwanted eavesdroppers. Historically it started with just a pencil and paper where letters or groups of letters would be substituted for others based on system that only the communicators knew. Simple mechanical devices like the syctale (a wooden rod with a particular shape and diameter) were used by the Spartan army on which to wrap messages around in order to decipher the content. As technology advanced further and  computers we developed more elaborate techniques and methods for encryption and decryption were devised with ever increasing complexity. Until fairly recently, all useful encryption algorithms had relied on using a cryptographic key that was the same for both the sender and receiver in order to decipher the content of their communications. One major issue with this is that the key must somehow be kept secret. This is problematic when often the key is itself required to be communicated over large distances publicly before it can be used. However in 1976, a fundamentally different approach was proposed by Whitfield Diffie and Martin Hellman, in a paper titled “New Developments in Cryptography”, which largely changed the way encryption was performed ever since. Asymmetric key encryption uses a pair of keys, one private that only you know and one public that anyone can know, and both of which are mathematically related, allowing you to decrypt the encryption performed by the person you are trying to communicate with in private. This video above goes a long way at making sense of how the private and public key is determined in cryptography.

“A Reassuring Fable” is the third chapter in the Sagan Series on the subject of human existence on Earth and the lives we all lead. Narrated by Carl Sagan alongside evocative cinematography, he touches upon the role of faith and of science in human experience, and so eloquently argues that we put aside our prejudice and differences for a worthy cosmic goal. 

Source: saganseries.com