Native-Like Spider Silk Produced in

Metabolically Engineered Bacteria

Science (July 27, 2010) — Researchers have long envied spiders’ ability to manufacture silk that is light-weighted while as strong and tough as steel or Kevlar. Indeed, finer than human hair, five times stronger by weight than steel, and three times tougher than the top quality man-made fiber Kevlar, spider dragline silk is an ideal material for numerous applications. Suggested industrial applications have ranged from parachute cords and protective clothing to composite materials in aircrafts. Also, many biomedical applications are envisioned due to its biocompatibility and biodegradability.

Unfortunately, natural dragline silk cannot be conveniently obtained by farming spiders because they are highly territorial and aggressive. To develop a more sustainable process, can scientists mass-produce artificial silk while maintaining the amazing properties of native silk? That is something Sang Yup Lee at the Korea Advanced Institute of Science and Technology (KAIST) in Daejeon, the Republic of Korea, and his collaborators, Professor Young Hwan Park at Seoul National University and Professor David Kaplan at Tufts University, wanted to figure out. Their method is very similar to what spiders essentially do: first, expression of recombinant silk proteins; second, making the soluble silk proteins into water-insoluble fibers through spinning.

For the successful expression of high molecular weight spider silk protein, Professor Lee and his colleagues pieced together the silk gene from chemically synthesized oligonucleotides, and then inserted it into the expression host (in this case, an industrially safe bacterium Escherichia coli which is normally found in our gut). Initially, the bacterium refused to the challenging task of producing high molecular weight spider silk protein due to the unique characteristics of the protein, such as extremely large size, repetitive nature of the protein structure, and biased abundance of a particular amino acid glycine. “To make E. coli synthesize this ultra high molecular weight (as big as 285 kilodalton) spider silk protein having highly repetitive amino acid sequence, we helped E. coli overcome the difficulties by systems metabolic engineering,” says Sang Yup Lee, Distinguished Professor of KAIST, who led this project. His team boosted the pool of glycyl-tRNA, the major building block of spider silk protein synthesis. “We could obtain appreciable expression of the 285 kilodalton spider silk protein, which is the largest recombinant silk protein ever produced in E. coli. That was really incredible.” says Dr. Xia.

But this was only step one. The KAIST team performed high-cell-density cultures for mass production of the recombinant spider silk protein. Then, the team developed a simple, easy to scale-up purification process for the recombinant spider silk protein. The purified spider silk protein could be spun into beautiful silk fiber. To study the mechanical properties of the artificial spider silk, the researchers determined tenacity, elongation, and Young’s modulus, the three critical mechanical parameters that represent a fiber’s strength, extensibility, and stiffness. Importantly, the artificial fiber displayed the tenacity, elongation, and Young’s modulus of 508 MPa, 15%, and 21 GPa, respectively, which are comparable to those of the native spider silk.

“We have offered an overall platform for mass production of native-like spider dragline silk. This platform would enable us to have broader industrial and biomedical applications for spider silk. Moreover, many other silk-like biomaterials such as elastin, collagen, byssus, resilin, and other repetitive proteins have similar features to spider silk protein. Thus, our platform should also be useful for their efficient bio-based production and applications,” concludes Professor Lee.

This work is published on July 26 in the Proceedings of the National Academy of Sciences (PNAS) online

Sourced & published by Henry Sapiecha

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WATCH YOUR PHOTOS DON’T GIVE YOU UP

Before you proudly go posting photos of your Ming vase online, you should be aware that computer-savvy burglars can likely use that photo to find out where you live. The same goes for photos or videos of your kids, yourself, or anything else that you don’t want strangers knowing how to locate. The practice of tracking people via their posted images is an example of “cybercasing”, and is possible because many digital cameras and smart phones, including the iPhone, automatically geotag their images by embedding the longitude and latitude at which they were taken. Even when uploaded to a website, the images still retain this information. By plugging the coordinates into a service like Google Street View, getting an address or an identifying landmark is entirely possible.

This disturbing fact was recently announced in a report published by the International Computer Science Institute (ICSI). Researchers Gerald Friedland and Robin Sommer wrote that they successfully obtained the home addresses of people who had posted photos in ads on Craigslist, despite those people having opted to keep their addresses hidden in their postings.

Creepier still, they were also able to obtain addresses where home videos of children had been shot, by searching under the tag “kids” on YouTube. They then proceeded to search for recent videos from those same users, that had been shot over 1,000 miles away. Within 15 minutes, they were able to determine that 13 of these video posters were likely still away on vacation, leaving their homes available for burglary.

While iPhones do geotag by default, it is possible to turn the feature off. The folks over at I Can Stalk U (they’re against stalking, not in favor of it) can show you how. For other phones and cameras, a Googling or a look through your user’s manual should tell you what you need to know.

Sourced & published by Henry Sapiecha

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STAR POWER USING LASERS FOR ENERGY DRIVE

A view inside the National Ignition Facility’s target chamber, a space easily big enough for technicians to stand inside. It is hoped the NIF will eventually be a major source of carbon-free energy.

(Credit: Lawrence Livermore National Lab)

LIVERMORE, Calif.–Think clean energy is a fantasy? What if the power of a star was applied to the problem?

That’s the approach being explored at the National Ignition Facility, a huge-scale experiment in laser fusion based at the Lawrence Livermore National Laboratory here. Scientists are looking at NIF as a potential key to producing large amounts of carbon-free power.

It’s not known if the system will ever bear the kind of fruit the scientists and administrators who run NIF would like. Still, the facility is a scientific wonder that can transform a single laser beam no wider than a human hair into 192 beams–each of which is 18 inches wide. Together, the beams are designed to produce 4 million joules, the amount of power that would produce 4 million watts of power in a single second.

Using star power for a clean-energy future (photos)

The NIF was completed in early 2009 and eventually will be used by the U.S. Department of Energy, as well as technicians from national laboratories, fusion energy researchers, academics, and others. It is “the world’s largest and highest-energy laser, [and] has the goal of achieving nuclear fusion and energy gain in the laboratory for the first time,” according to the Lawrence Livermore National Lab, “in essence, creating a miniature star on Earth.”

This is serious high technology. The NIF employs a series of amplifiers and mirrors known as switchyards to route and split the original hair’s-width laser beam over a total distance of 1,500 meters. After being separated by pre-amplifiers into 48 beams, each beam is then split into four beams, and then all are injected into the 192 main laser amplifier beamlines, according to the NIF.

The hope is that NIF will be online as a power plant within 15 to 20 years. For now, the facility is a proof-of-concept system, albeit one comprising two 10-story buildings and more than $3 billion of investment. Eventually, the 192 laser beams reunite to focus on a target fuel pellet that is just millimeters in size, yet placed inside a target chamber that towers over the technicians who sometimes work inside.

And 192 laser beams of this magnitude create some serious heat. The theoretical maximum, according to LLNL retiree and docent Nick Williams, is 100 million degrees Celsius.

For now, because of the amount of power necessary to produce the beams, and the heat created, scientists are only able to fire the laser system once every two or three hours. Eventually, the idea would be to fire it many times a second.

And by 2030, it is hoped, the NIF will be helping produce commercial power and helping scientists and researchers better understand the nature of the universe. That, it would seem, would be a main benefit of producing what amounts to a small star, right here in the middle of Northern California.

On June 24, Geek Gestalt will kick off Road Trip 2010. After driving more than 18,000 miles in the Rocky Mountains, the Pacific Northwest, the Southwest and the Southeast over the last four years, I’ll be looking for the best in technology, science, military, nature, aviation and more throughout the American northeast. If you have a suggestion for someplace to visit, drop me a line. In the meantime, you can follow my preparations for the project on Twitter @GreeterDan and @RoadTrip.

Sourced and published by Henry Sapiecha 7th June 2010

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‘Computer Viruses gone to your head?’

Science (May 26, 2010) — A scientist at the University of Reading has become the first person in the world to be infected by a computer virus.

Dr Mark Gasson, from the School of Systems Engineering, contaminated a computer chip which had been inserted into his hand as part of research into human enhancement and the potential risks of implantable devices.

These results could have huge implications for implantable computing technologies used medically to improve health, such as heart pacemakers and cochlear implants, and as new applications are found to enhance healthy humans.

Dr Gasson says that as the technology behind these implants develops, they become more vulnerable to computer viruses.

“Our research shows that implantable technology has developed to the point where implants are capable of communicating, storing and manipulating data,” he said. “They are essentially mini computers. This means that, like mainstream computers, they can be infected by viruses and the technology will need to keep pace with this so that implants, including medical devices, can be safely used in the future.”

Dr Gasson will present his results next month at the IEEE International Symposium on Technology and Society in Australia, which he is also chairing.

A high-end Radio Frequency Identification (RFID) chip was implanted into Dr Gasson’s left hand last year. Less sophisticated RFID technology is used in shop security tags to prevent theft and to identify missing pets.

The chip has allowed him secure access to his University building and his mobile phone. It has also enabled him to be tracked and profiled. Once infected, the chip corrupted the main system used to communicate with it. Should other devices have been connected to the system, the virus would have been passed on.

Dr Gasson said: “By infecting my own implant with a computer virus we have demonstrated how advanced these technologies are becoming and also had a glimpse at the problems of tomorrow.

“Much like people with medical implants, after a year of having the implant, I very much feel that it is part of my body. While it is exciting to be the first person to become infected by a computer virus in this way, I found it a surprisingly violating experience because the implant is so intimately connected to me but the situation is potentially out of my control.

“I believe it is necessary to acknowledge that our next evolutionary step may well mean that we all become part machine as we look to enhance ourselves. Indeed we may find that there are significant social pressures to have implantable technologies, either because it becomes as much of a social norm as say mobile phones, or because we’ll be disadvantaged if we do not. However we must be mindful of the new threats this step brings.”

Sourced and published by Henry Sapiecha 28th May 2010

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Research Targets Lethal Chagas’

Disease Spread by Insect

That Bites Lips

Science (Apr. 29, 2010) — It makes your skin crawl — a bug that crawls onto your lips while you sleep, drawn by the exhaled carbon dioxide, numbs your skin, bites, then gorges on your blood. And if that’s not insult enough, it promptly defecates on the wound-and passes on a potentially deadly disease.

Now Jean-Paul Paluzzi, a PhD candidate in biology at the University of Toronto Mississauga, believes that manipulating physiology to prevent the insects from leaving their messy calling card represents the best hope for stopping the transmission of the illness, known as Chagas’ disease.

“This is a disease of the poor,” says Paluzzi, who has visited parts of the world affected by the illness. “The bugs are found in makeshift homes with mud walls and palm tree-like ceilings. Unfortunately, the people of Central and South America that this affects don’t have sufficient voice to get help. Given that there are roughly 15 to 19 million people that are infected-a substantial proportion of that area’s population-it’s a disease that’s been neglected.”

Chagas’ disease is one of the major health problems in South and Central America and is spread by reduvid bugs, also known as “kissing bugs” because of their fondness for lips. The disease they transmit is caused by Trypanosoma cruzi, a parasite that lives in their gut. In the initial acute stage, symptoms are relatively mild, but as the disease progresses over several years, serious chronic symptoms can appear, such as heart disease and malformation of the intestines. Without treatment, it can be fatal. Currently, insecticide sprays are used to control insect populations, and anti-parasitic drugs are somewhat successful at treating acute infections.

Once the disease is chronic, it cannot be cured.

To make matters worse, kissing bugs are particularly “bloodthirsty.” In mosquitoes, which go through four distinct stages of development, only adult females feed on blood (and potentially transmit disease). This means that pest control methods need to target only one out of eight stages (when you include both sexes). But in kissing bugs, each sex feeds on blood through all fives stages of development. “So you have about a ten-fold greater chance of infection just because of the number of times that these insects have to feed,” says Paluzzi.

His research focuses on insect diuresis-more specifically, the genes and peptides that control how the kissing bug eliminates excess fluid in its gut after it gorges on blood. For the insect, the real prize in its meal is the red blood cells, while the water and salt is “excess baggage.” After they feed, the bugs are bloated and sluggish, and must jettison the waste so they can make their escape.

Here’s how it happens: when the kissing bug finds a snoozing victim and feeds, its levels of serotonin and diuretic hormones rise sharply, targeting the insect’s midgut and Malpighian tubules (the equivalent of kidneys), and triggering the release of waste. About four hours later, a peptide named CAP2b is released in the insect’s gut, abolishing the effect of the diuretic hormones.

Paluzzi has identified two genes (RhoprCAPA-alpha and RhoprCAPA-beta) that carry the chemical recipe for the peptides that stop diuresis. With that information, he hopes to create a peptide “agonist”-something that would enhance the activity of the CAP2B peptide and prevent the insect from leaving waste (and the parasite) on the wound. In theory, says Paluzzi, this might be an insecticide-like room spray or topical lotion that is biologically stable and has no effect on humans or other insects. Paluzzi is collaborating with a structural biochemist at the U.S. Food and Drug Administration in Texas, with the ultimate goal of creating a pest control solution, but he cautions that a market-ready product is many years away.

The research was funded by the Natural Sciences and Engineering Research Council of Canada, through a discovery grant to Professor Ian Orchard of the Department of Biology and a Canada Graduate Scholarship to Paluzzi.

Sourced and published by Henry Sapiecha 2nd May 2010

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Rust Removal Using – Soda Pop?

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Blueprint for ‘Artificial Leaf’

Mimics Mother Nature and helps to

turn water to hydrogen for fuel

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Seed of extinct date palm

sprouts after 2,000 years

(06-12) 04:00 PST Kibbutz Ketura, Israel — 2005-06-12 04:00:00 PST Kibbutz Ketura, Israel — It has five leaves, stands 14 inches high and is nicknamed Methuselah. It looks like an ordinary date palm seedling, but for UCLA- educated botanist Elaine Solowey, it is a piece of history brought back to life.

Planted on Jan. 25, the seedling growing in the black pot in Solowey’s nursery on this kibbutz in Israel’s Arava desert is 2,000 years old — more than twice as old as the 900-year-old biblical character who lent his name to the young tree. It is the oldest seed ever known to produce a viable young tree.

The seed that produced Methuselah was discovered during archaeological excavations at King Herod’s palace on Mount Masada, near the Dead Sea. Its age has been confirmed by carbon dating. Scientists hope that the unique seedling will eventually yield vital clues to the medicinal properties of the fruit of the Judean date tree, which was long thought to be extinct.

Solowey, originally from San Joaquin (Fresno County), teaches at the Arava Institute for Environmental Studies at Kibbutz Ketura, where she has nurtured more than 100 rare or near-extinct species back to life as part of a 10-year project to study plants and herbs used as ancient cures.

In collaboration with the Louis L. Borick Natural Medicine Center at Hadassah Hospital in Jerusalem, named in honor of its Southern California- based benefactor, Solowey grows plants and herbs used in Tibetan, Chinese and biblical medicine, as well as traditional folk remedies from other cultures to see whether their effectiveness can be scientifically proved.

In experiments praised by the Dalai Lama, for example, Borick Center Director Sarah Sallon has shown that ancient Tibetan cures for cardiovascular disease really do work.

The San Francisco Chronicle was granted the first viewing of the historic seedling, which sprouted about four weeks after planting. It has grown six leaves, but one has been removed for DNA testing so scientists can learn more about its relationship to its modern-day cousins.

The Judean date is chronicled in the Bible, Quran and ancient literature for its diverse powers — from an aphrodisiac to a contraceptive — and as a cure for a wide range of diseases including cancer, malaria and toothache.

Sourced and published by Henry Sapiecha 8th April 2010

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