Two researchers at Weill Cornell Medical College have deciphered a mouse‘s retina‘s neural code and coupled this information to a novel prosthetic device to restore sight to blind mice. Furthermore, the results show, using 9,800 optogenetically stimulated ganglion cell responses, that the combined effect of using the code and high-resolution stimulation is able to bring prosthetic capabilities into the realm of normal image representation. The researchers say they have also cracked the code for a monkey retina - which is essentially identical to that of a human – and hope to quickly design and test a device that blind humans can use.
Sheila Nirenberg and Chethan Pandarinath: Retinal prosthetic strategy with the capacity to restore normal vision, In: PNAS Early Edition, August 13, 2012, DOI: 10.1073/ pnas.1207035109:
http://dx.doi.org/10.1073/pnas.1207035109 http://nyp.org/
Since the physicists did not previously take account of this competition in their models, their calculati- ons of the transition temperature, where superconductivity sets in, remained inaccurate. In further work, the researchers at the Stuttgart Max Planck Institute have gained insights into how superconducting materials interact with magnetic ones. They observed that the electronic properties affect crystal vibrations to a greater extent than was to be expected. This effect could help to control material properties such as superconductivity or thermoelectricity. Whether a material conducts electricity without losses is not least a question of the right temperature. In future it may be possible to make a more reliable prediction for high-temperature superconductors. These materials lose their resistance if they are cooled with liquid nitrogen, which is relatively easy to handle. An international team, in which physicists of the Max Planck Institute for Solid State Research in Stuttgart played a crucial role, has now discovered that this form of superconductivity competes with charge density waves, i.e. with a periodically fluctuating distribution of the charges.
Image: Researchers at the Max Planck Institute for Solid State Research have discovered charge density waves in ceramic yttrium and neodymium barium cuprates. They form above the temperature at which the m aterial becomes superconducting and thus loses its electrical resistance, slightly distorting the crystal lattice, as indicated in a layer of the crystal lattice by the irregular distances between the atoms (blue spheres). The superconductivity competes with the charge density waves, and it is probably down to a coincidence that superconductivity prevails at a certain temperature. © Daniel Pröpper/MPI for Solid State Research
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