New Scientist |October 22, 2010

TO MAKE it harder for bioterrorists to build dangerous viruses from scratch, guidelines for firms who supply “custom DNA” are being introduced in the US.

The US and other countries restrict who can work with certain germs, but it might be possible to build some viruses from their genes. A number of firms supply DNA sequences to order. A 2005 investigation by New Scientist raised alarms when it found that only five out of 12 of these firms in North America and Europe always screened orders for sequences that might be used in bioweapons.

The US now wants firms to verify a customer’s identity and make sure they are not on a list of banned buyers. It also wants them to screen orders for sequences that are unique to Select Agents, a list of microbes the US deems dangerous.

However, scientists commenting on the draft rules earlier this year fear that sequences from microbes other than Select Agents might also be dangerous. The US Department of Health says not enough is known about them to say which ones should arouse a firm’s suspicions. Other potential weaknesses include the fact that the rules are voluntary, and that much custom DNA is made outside the US.

New Scientist | November 3, 2010

Groups in Germany and the US have been testing electronic implants aimed at restoring vision to people with retinal dystrophy. The condition is hereditary or age-related, and causes degeneration of the photoreceptors – light-sensitive cells in the retina – leading to blindness. It affects 15 million people worldwide.

Eberthart Zrenner and colleagues at the University of Tübingen in Germany have developed a microchip carrying 1500 photosensitive diodes that slides into the retina where the photoreceptors would normally be. The diodes respond to light, and when connected to an outside power source through a wire into the eye, can stimulate the nearby nerves that normally pass signals to the brain, mimicking healthy photoreceptors.

The team reports that their first three volunteers could all locate bright objects. One could recognise normal objects and read large words.

Nerves in the eye normally adapt to visual input and stop transmitting signals after a short time. Tiny movements of the eye overcome this by constantly projecting the image back and forth between neighbouring nerve cells so that each has time to recover and resume transmitting signals. Because the implant is inside the eye, this mechanism worked normally in the trials. Another device being tested sends images from a head-mounted camera to ocular nerves, but as the image forms outside the eye the tiny movements cannot maintain it and patients must rapidly shake their head instead.

As a safety precaution, the implants in this first pilot study were removed after several weeks, says Walter Wrobel, head of Retina-Implant, a company based in Reutlingen, Germany, formed by the researchers to eventually market the implant. “Based on the results of this study, we have designed a new system, which is being implanted permanently, or as long as patients like it.”

In the new system, the power source connects to the retinal implant via a mechanical coupling through intact skin, not via a wire through an incision in the skin as the earlier system did. “That means they can shower easily, leave the hospital and go around town on their own,” says Zrenner. “They can go out for a meal, and really see things, like a nice glass of beer.”

Wired Science | January 30, 2008

Hacking the climate to save ourselves from global warming’s worst consequences is a real possibility that we’ve explored several times here at Wired and elsewhere. But a new article in Foreign Policy by futurist Jamais Cascio takes a deep look at the geopolitical dilemmas presented by our prospective ability to intentionally alter the climate. He argues that the the “subtle, long-term aspects of geoengineering could make it appealing” to states looking for “alternative, unexpected ways of boosting their strategic power relative to competitors.”

The offensive use of geoengineering could take a variety of forms.
Overproductive algae blooms can actually sterilize large stretches of ocean over time, effectively destroying fisheries and local ecosystems.
Sulfur dioxide carries health risks when it cycles out of the stratosphere. One proposal would pull cooler water from the deep oceans to the surface in an explicit attempt to shift the trajectories of hurricanes. Some actors might even deploy counter-geoengineering projects to slow or alter the effects of other efforts.

Cascio also notes that it would be hard to detect geoengineering efforts designed to combat global warming or its effects with those intended to harm another country’s environment, which is a total bonus for military planners. He recommends that we both try to avoid a climate disaster, but just in case,  also “expand the global environmental sensor and satellite networks allowing us to monitor ecosystem changes—and manipulation.”

Note that Brandon has touched on some of these issues in an excellent article and blog post: Global Climate Engineering: Who Controls the Thermostat? and China Leads Weather Control Race.

And another interesting and/or deeply disturbing article …

Military Scientists Explore Planet-Hacking

Danger Room | March 17, 2009

Some of the military’s leading scientific advisers are looking into the idea of remaking the planet’s environment, to stave off global warming.

The idea of “geoengineering” — hacking the Earth’s climate, to prevent more radical changes — has been kicking around the scientific fringes for years. One scheme calls for adding iron to the ocean, to stimulate the growth of greenhouse gas-absorbing algae. Another for “loading the skies” with sulfate particles that “act as mini-reflectors, shading out sunlight and cooling the Earth.” A third, “covering the Arctic with dust.” Most mainstream climatologists have responded to the proposals with a combination of snickers and horror; the environment is such a chatoic system, they argue, that there’s no telling what such wholesale monkeying around with it will do.

In recent months, however, several “top institutions have launched efforts to study the subject,” the ScienceInsider blog notes. The Pentagon’s secretive JASON scientific panel is schedule to discuss geonengineering soon. The National Academies are hosting a workshop over the summer. The U.K. Royal Society should have study out by then, too.

The Defense Sciences Research Council, which advises Pentagon premiere research arm Darpa, is meeting today at Stanford University to explore geoengineering. But at least one of the scientists that’s scheduled to attend will be arguing against planet-hacking, not in favor of it.

“The last thing we need is to have Darpa developing climate-intervention technology,” Ken Caldeira of the Carnegie Institution for Science tells ScienceInsider.

He says he agreed to go to the meeting “to try to get Darpa not to develop geoengineering techniques. Geoengineering is already so fraught with social, geopolitical, economic, and ethical issues; why would we want to add military dimensions?” He adds, however, that he would support Darpa studying the topic in case an adversary were to use it.

Darpa has been working on environmental issues for years — putting money into algae-based fuel and trash-based “bioplastics.”
It’s part of a larger, far-flung, often-disjointed series of Pentagon initiatives to kick the fossil fuel habit, and reduce the military’s carbon footprint. Giant solar arrays, wind-powered bases, and garbage-munching generators in Baghdad are all part of the mix. We’ll see if a more radical global warming answer will soon be, too.

New Scientist | 25 November 2008

Gold leaf doesn’t grow on trees, but it can now harvest power from the Sun. A team of US chemical engineers has extracted photosynthetic molecules from plants and attached them to thin sheets of gold, creating a photosynthesising cyborg.

Organisms have been photosynthesising for at least 3.5 billion years, and over that time have developed elegant combinations of protein and light-absorbing dyes to help convert sunlight into power.

Rather than reinventing the wheel, Kane Jennings and Peter Ciesielski’s team at Vanderbilt University in Nashville, Tennessee, decided to take those proteins to build their own photosynthetic devices.

The idea grew from the work of Elias Greenbaum at the Oak Ridge National Laboratory, also in Tennessee, who in the late 1990s showed that a protein complex, known as PS1, extracted from spinach leaves remained active when immobilised on a gold surface.
Artificial leaf

Since then the process for extracting PS1 from plants has been perfected, says Jennings, laying the ground for his group to use those light-harvesting proteins to make an artificial leaf.

Jennings and Ciesielski made their device using commercially available gold-silver alloy leaf.

Concentrated nitric acid was used to dissolve away the silver to leave gold leaf with nanoscale pores. This gave it a high surface area that allows a large amount of PS1 to be attached. It also made the leaf thin enough for light to penetrate. The finished material was stretched over a thicker gold substrate for support.

PS1 complexes were attached to the leaf by first coating the porous gold in thiols – chemical molecules that have a free end able to form strong bonds with the proteins.

When the complete cyborg leaf is placed under light, the PS1 complexes generate electrons that flow into the gold and can be harvested as electric current.

In a living plant, those electrons would be used to reduce compounds as part of a chemical chain that produces new energy stores in the form of carbohydrates.
Low power

The most rigorously tested artificial leaf produces a current of around 800 nanoamps per square centimetre. That is far from efficient enough to be economic, but the researchers are already experimenting with a new model.

“We are currently investigating PS1 films up to one micrometer thick,” says Jennings. “These films can generate up to 2 microamps per centimetre square, and can power an inexpensive calculator.”

Although the cyborg devices are still far behind the best silicon-based solar cells the new approach may become more competitive in future. The new design is relatively simple, and sourcing cheap plant leaves and a suitable substrate to make cyborg leaves from should be easy.

The system is still too delicate to be exposed to direct sunlight, which would burn out the PS1 proteins. Finding a way to protect them, and building leaves that pack in more of them will improve output further. That might even turn the artificial leaves green – they currently appear rusty red due to the properties of the nanoporous gold.

Greenbaum is impressed with the direction his original discovery has taken. “This is very nice work by an outstanding group,” he says. “The results represent an important research advance in bio-inspired solar energy conversion.”