Cornell Scientists develop 'bionic eye'

Cornell University Researchers have dramatically boosted the performance of retinal implants by cracking a “code” that communicates visual signals to the brain.

The code consists of specific patterns of electrical pulses.

By incorporating it into their device, the scientists came close to restoring normal vision in totally blind mice lacking any light-sensitive cells.

Tests showed that the animals were able to discern facial features and track images with their eyes.

A reconstruction based on electrical signals from the implant showed recognisable features of a baby’s face.

In contrast, a standard retinal implant without the new encoder produced a confused pattern of bright and dark spots.

The results, published in the journal Proceedings of the National Academy of Sciences, could pave the way to life-changing retinal prosthetics, the scientists believe.

Even the best retinal implants currently restore only very limited vision, allowing patients to see spots of light and high-contrast edges.

The US team led by Dr Sheila Nirenberg, from Cornell University in New York, wrote: “Our results show that incorporation of the code dramatically increases prosthetic performance, well beyond what can be achieved just by increasing resolution.

“Moreover, they show that the combination of the code and high-resolution stimulation is able to bring prosthetic capabilities up to the level of normal or near-normal image presentation.”

Scientists around the world are exploring the potential of retinal implants to help people with degenerative blinding diseases such as retinitis pigmentosa.

More than 20 million people around the world are blind or at risk of blindness due to the diseases. Typically, they destroy the light-sensitive photoreceptors of the retina but leave nerve connections intact.

By replacing natural photoreceptors with artificial ones, it is hoped that some degree of sight can be restored. However, results to date have been disappointing. Although some sight can be restored, serious visual impairment remains.

The new study shows that boosting resolution - effectively the number of “pixels” the eye can see - is not enough on its own. For the image to be relayed successfully to the brain, the light signals must first be translated into the right patterns of electrical impulses.

Retinal Ganglion cells, a type of nerve cell within the retina, are responsible for communicating the visual messages.

In congenitally blind mice fitted with the new implant, the ganglion cells fired correctly almost 90% of the time, said the scientists.

Behavioural and eye-tracking experiments suggested that a high level of vision had been restored to the mice.

In one striking test, an image of a baby’s face was reconstructed from the “spike trains” - electrical signals - produced by blind mouse retinas with standard and encoder implants.

Features that could not be seen at all in the “standard” reconstruction were clearly visible from the new implant.

“Not only is it possible to discern that the image is a baby’s face, but also it is possible to tell that it is this particular baby,” the scientists wrote.

They concluded: “In sum, our results show that incorporating the code dramatically increases prosthetic capabilities. Although increasing resolution also improves performance, there is an inherent ceiling on the quality of image this can produce; adding the code breaks through this barrier. The coded output combined with high-resolution stimulation makes natural vision restoration possible.”

Fight nematode parasites with compounds in worms

Worms are important decomposers in soil, but in humans they spell trouble. Parasitic nematodes infect some 2 billion people.

Researchers are hopeful the discovery of a new class of molecules could lead to prevention and treatments for worm parasites.

(Credit: Image of "Caenorhabditis elegans" via Shutterstock)

Hookworms, whipworms, Ascaris, Guinea worms, and trichina worms are just a few parasitic nematodes that infect some 2 billion people.

Researchers report that nematodes use the newly discovered class of small molecules to signal such processes as growing, developing, mating, and moving toward or away from an area.

“All of these nematodes speak the same chemical language,” through the use of compounds called ascarosides, says study co-author Frank Schroeder, a research scientist at the Boyce Thompson Institute for Plant Research and adjunct assistant professor at Cornell University.

The study, published online in the journal Current Biology, was led by Stephan von Reuss, a postdoctoral associate in Schroeder’s lab, and Andrea Choe, a postdoctoral scholar in the lab of co-author Paul Sternberg, a biologist at the (WormLab) California Institute of Technology.

Since nematodes are the only known organisms to use ascarosides, “we don’t have to be afraid of interfering with similar biochemistry in animals, plants, or humans,” Schroeder says, as researchers seek to identify species-specific ascaroside molecules that may enable novel approaches to deter or disrupt the survival or reproduction of parasitic worms.

Researchers in Schroeder’s lab have already filed for three patents, one that covers the structures of various ascarosides, one that covers ascarosides for use as agents to protect plants, and one that makes claims to how to use the compounds to treat or prevent human disease.

The researchers first discovered ascarosides as a signaling molecule in C. elegans, a nematode used as a model organism to study cell, developmental, and nervous system biology, as well as human aging and diabetes.

“We then thought, if C. elegans uses this chemical language, perhaps other nematodes do too,” Schroeder says.

Raed the full report here:  DOI: 10.1016/j.cub.2012.03.024

NEEMO 16 mission scheduled for June: Asteroid underwater training

The next NASA Extreme Environment Mission Operations (NEEMO) mission is being scheduled for June, with teams already preparing for a recon trip ahead of the exercise.

The underwater training exercises are staged at the Aquarius underwater habitat in Key Largo, Florida – simulating the conditions and protocols for a real Near Earth Asteroid (NEA) mission.

NEEMO 15 was the first real full scale operation – even including Mission Operations Directorate (MOD) teams – continuing the trend of testing equipment and operations required for exploration of Near-Earth Asteroids (NEAs).

The mission treated the underwater environment like a giant Neutral Buoyancy Laboratory (NBL), allowing for specialist divers to simulate working on a NEA, communicating – with time delays – with mission control and practising the use of tools to work on an asteroid.

The October NEEMO 15 mission was led by NASA astronaut and former International Space Station (ISS) crew member Shannon Walker.

The crew included Japan Aerospace Exploration Agency astronaut Takuya Onishi and Canadian Space Agency astronaut David Saint-Jacques from the 2009 NASA astronaut class.

Steven Squyres of Cornell University and scientific principal investigator for the Mars Exploration Rover Project, joined James Talacek and Nate Bender of the University of North Carolina, Wilmington – who are both professional aquanauts.

NASA astronauts Stan Love, Richard Arnold and Mike Gernhardt, all veteran spacewalkers, participated in the NEEMO mission from the DeepWorker submersible, which they piloted.

The submersible is a key element of simulating a NEA mission, acting as an underwater stand-in for the Multi Mission Space Exploration Vehicle (MMSEV), which is currently the leading concept to be the main NEA exploration vehicle at the site at the asteroid, utilizing its robotic arms and crew airlock.

Aquarius acts as the Deep Space Hab (DSH) for these missions, a large element of hardware that would arrive at the NEA after being launched from Earth on the Space Launch System (SLS) – likely the 105mt Block 1A Heavy Lift Launch Vehicle (HLV).

NEEMO 15 worked on three major elements of a NEA mission, such as how to anchor to the surface via the “excursion lines”; how to move around; and how best to collect data and materials.

Read More about NEEMO here

Rocket Launch Image: University of Alaska's Poker Flat Research Range near Fairbanks, Alaska

A rocket flies through the aurora borealis after lifting off from the University of Alaska's Poker Flat Research Range near Fairbanks, Alaska. 

The mission was launched by a NASA funded group of 60 researchers studying electrical activity in the aurora borealis and the likelihood it is interfering with GPS and other signals. 

Cornell University says the 46-foot rocket sent back data as it flew through the aurora at an altitude of 217 miles.

Picture: NASA Wallops, Lee Wingfield/AP

The Galactic evolution of phosphorus

As a galaxy evolves, its chemical composition changes and the abundance ratios of different elements are powerful probes of the underlying evolutionary processes.

Phosphorous is an element whose evolution has remained quite elusive until now, because it is difficult to detect in cool stars.

The infrared weak P I lines of the multiplet 1, at 1050-1082 nm, are the most reliable indicators of the presence of phosphorus.

The availability of CRIRES at VLT has permitted access to this wavelength range in stellar spectra.We attempt to measure the phosphorus abundance of twenty cool stars in the Galactic disk.

The spectra are analysed with one-dimensional model-atmospheres computed in Local Thermodynamic Equilibrium (LTE).

The line formation computations are performed assuming LTE. The ratio of phosphorus to iron behaves similarly to sulphur, increasing towards lower metallicity stars. Its ratio with respect to sulphur is roughly constant and slightly larger than solar, [P/S]=0.10+- 0.10.

We succeed in taking an important step towards the understanding of the chemical evolution of phosphorus in the Galaxy. However, the observed rise in the P/Fe abundance ratio is steeper than predicted by Galactic chemical evolution model model developed by Kobayashi and collaborators.

Phosphorus appears to evolve differently from the light odd-Z elements sodium and aluminium. The constant value of [P/S] with metallicity implies that P production is insensitive to the neutron excess, thus processes other than neutron captures operate.

We suggest that proton captures on 30Si and alpha captures on $27Al are possibilities to investigate. We see no clear distinction between our results for stars with planets and stars without any detected planet.

The Galactic evolution of phosphorus

Present from Bill Gates Microsoft - A Free Gift of Physics

Bill Gates and Microsoft Research have joined forces on a new website featuring the physics lectures of Richard Feynman, as presented at Cornell University in 1964.

The dapper and brilliant Feynman waxes eloquent on topics such as the Law of Gravitation and Symmetry in Physical Law. No mention of Windows from the ones I checked out.

Gates privately bought the rights to the lecture series so that he could make it publicly available via the very slick Silverlight-enabled Project Tuva website, which features a moving timeline, ability to take notes and more. The name “Tuva” was inspired by Feynman’s interest in the Russian republic of that name.