'Smart' mice teach scientists about learning process, brain disorders

'Smart' mice teach scientists about learning process, brain disorders

Dr. James Bibb (center), assistant professor of psychiatry, along with Drs. Craig Powell, assistant professor of neurology, and Donald Cooper, assistant professor of psychiatry, was involved in research showing that mice lacking a specific enzyme in their brains are more adept at learning than their normal cousins. The results might ultimately reveal a new mechanism of learning in the brain, which might serve in humans as a target for treating disorders such as post-traumatic stress disorder, Alzheimer’s disease or drug addiction.

Technorati tags: genetic learning

Hydrogen breakthrough could open the road to carbon-free cars

Hydrogen breakthrough could open the road to carbon-free cars

A new breakthrough in hydrogen storage technology could remove a key barrier to widespread uptake of non-polluting cars that produce no carbon dioxide emissions.

UK scientists have developed a compound of the element lithium which may make it practical to store enough hydrogen on-board fuel-cell-powered cars to enable them to drive over 300 miles before refuelling. Achieving this driving range is considered essential if a mass market for fuel cell cars is to develop in future years, but has not been possible using current hydrogen storage technologies.

Technorati tags: hydrogen, fuel cells

Nanoparticles Delivery of 'Suicide DNA' Kills Prostate Tumors

Nanoparticles Delivery of 'Suicide DNA' Kills Prostate Tumors

Using nanoparticles developed by members of the Alliance for Nanotechnology in Cancer, a team of investigators at the Lankenau Institute for Medical Research, in Philadelphia, has developed a DNA-based therapeutic agent that has the potential to treat both enlarged prostates and localized prostate tumors. When tested in mice, this new agent specifically targeted prostate tissue, producing no toxic effects in surrounding tissues.

Writing in the journal The Prostate, a team of investigators led by Janet Sawicki, Ph.D., described its use of polymer nanoparticles to delivery a so-called suicide gene that codes for the production of diphtheria toxin. The biodegradable and biocompatible polymer nanoparticles were developed by Robert Langer, Ph.D., and his colleagues at the MIT-Harvard Center of Cancer Nanotechnology Excellence.

To make their suicide gene specific for prostate tissue, the investigators linked it to a gene regulator that responds only in the presence of a prostate-specific protein. Without this protein, the diphtheria toxin gene remains inactive, which makes it non-toxic to any cells but those in the prostate.

When injected directly into the prostate, this nanoparticle-encapsulated gene construct triggered a significant reduction in the size of the prostate gland and on the size of prostate tumors. The investigators showed that this shrinkage resulted from cells undergoing apoptosis, or programmed cell death. In fact, the researchers found that a single injection of nanoparticles triggered apoptosis in 80 percent of tumor cells present in the tissue. In contrast, direct injection of the gene construct alone, that is, without the nanoparticle delivery vehicle, produced no effect on prostate tissue or tumors.

Technorati tags: prostrate cancer, nanoparticles

Nanomedicine opens the way for nerve cell regeneration

Nanomedicine opens the way for nerve cell regeneration

The ability to regenerate nerve cells in the body could reduce the effects of trauma and disease in a dramatic way. In two presentations at the NSTI Nanotech 2007 Conference, researchers describe the use of nanotechnology to enhance the regeneration of nerve cells. In the first method, developed at the University of Miami, researchers show how magnetic nanoparticles (MNPs) may be used to create mechanical tension that stimulates the growth and elongation of axons of the central nervous system neurons. The second method from the University of California, Berkeley uses aligned nanofibers containing one or more growth factors to provide a bioactive matrix where nerve cells can regrow.

It is known that injured neurons in the central nervous system (CNS) do not regenerate, but it is not clear why. Adult CNS neurons may lack an intrinsic capacity for rapid regeneration, and CNS glia create an inhibitory environment for growth after injury. Can these challenges be overcome even before we fully understand them at a molecular level "why axons in central nervous system do not regenerate?"

Dr. Mauris N. De Silva describes the novel nanotechnology based approach designed that includes the use of magnetic nanoparticles and magnetic fields for addressing the challenges associated with regeneration of central nervous system after injury. "By providing mechanical tension to the regrowing axon, we may be able to enhance the regenerative axon growth in vivo". This mechanically induced neurite outgrowth may provide a possible method for bypassing the inhibitory interface and the tissue beyond a CNS related injury. Using optic nerve and spinal cord tissues as in vivo models and dissociated retinal ganglion neurons as an in vitro model, De Silva and his colleagues are currently investigating how these magnetic nanoparticles can be incorporated into neurons and axons at the site of injury.

Technorati tags: nanomedicine, nerve cell regeneration

Google Press Center: Press Release

Google Press Center: Press Release

Google Begins Move to Universal Search

Google Introduces New Search Features and Unveils New Homepage Design

MOUNTAIN VIEW, Calif. (May 16, 2007) – Google Inc. (NASDAQ: GOOG) today announced its critical first steps toward a universal search model that will offer users a more integrated and comprehensive way to search for and view information online. The company also introduced an updated homepage design and several new navigation features that make it faster and easier for users to find the information they are looking for.

"Our focus has always been making our users' search experience as simple and straightforward as possible," said Marissa Mayer, vice president of search products and user experience at Google. "The ultimate goal of universal search is to break down the silos of information that exist on the web and provide the very best answer every time a user enters a query. While we still have a long way to go, today's announcements are a big step in that direction."

Google's vision for universal search is to ultimately search across all its content sources, compare and rank all the information in real time, and deliver a single, integrated set of search results that offers users precisely what they are looking for. Beginning today, the company will incorporate information from a variety of previously separate sources – including videos, images, news, maps, books, and websites – into a single set of results. At first, universal search results may be subtle. Over time users will recognize additional types of content integrated into their search results as the company advances toward delivering a truly comprehensive search experience.

For example, a user searching for information on the Star Wars character Darth Vader is likely interested in all the information related to the character and the actor – not just web pages that mention the movie. Google will now deliver a single set of blended search results that include a humorous parody of the movie, images of the Darth Vader character, news reports on the latest Lucas film, as well as websites focused on the actor James Earl Jones – all ranked in order of relevance to the query. Users no longer have to visit several different Google search properties to find such a wide array of information on the topic.

Technorati tags: internet, search, google

Researchers Create New Form of Matter

Researchers Create New Form of Matter

The work introduces a new method of moving energy from one point to another as well as a low-energy means of producing a light beam like that from a laser. The Pitt researchers and their collaborators at the Bell Labs of Alcatel-Lucent in New Jersey detail the process in the May 18 issue of the journal Science.

The new state is a solid filled with a collection of energy particles known as polaritons that have been trapped and slowed, explained lead investigator David Snoke, an associate professor in the physics and astronomy department in Pitt's School of Arts and Sciences. Snoke worked with Pitt graduate students Ryan Balili and Vincent Hartwell on the project.

Using specially designed optical structures with nanometer-thick layers-which allow polaritons to move freely inside the solid-Snoke and his colleagues captured the polaritons in the form of a superfluid. In superfluids and in their solid counterparts, superconductors, matter consolidates to act as a single energy wave rather than as individual particles.

In superconductors, this allows for the perfect flow of electricity. In the new state of matter demonstrated at Pitt-which can be called a polariton superfluid-the wave behavior leads to a pure light beam similar to that from a laser but is much more energy efficient.

Technorati tags: energy, superfluid

New gene therapy targets cholesterol - health - 17 May 2007 - New Scientist

New gene therapy targets cholesterol - health - 17 May 2007 - New Scientist

First there was gene therapy, then came RNA interference. Now the latest technology promising to regulate gene expression has been used therapeutically for the first time - if only in mice - to cut cholesterol levels. The technique, termed microRNA (miRNA) inhibition, has also been used to stop hepatitis C infecting cells.

It is related to earlier forms of RNA interference (RNAi), such as siRNA - in which a double-stranded "short interfering RNA" is used to intercept and destroy messenger RNA (mRNA) before it can be translated into protein. But unlike siRNA, which works to silence genes, miRNA inhibition increases the amount of protein that gets produced by intercepting the molecules - miRNAs - that normally act as a brake on mRNA translation (see Diagram).

MicroRNAs are thought to control up to 30 per cent of all gene activity, with one type responsible for directing the expression of whole networks of genes, rather than just single genes. Changes in the expression of miRNAs have been implicated in cancer and other diseases, including viral infections (New Scientist, 11 June 2005, p 18).

RNAi-based therapies have so far failed to take off because of the difficulty of getting the therapeutic molecules into target cells, but according to work conducted at Santaris Pharma in Hørsholm, Denmark, miRNA-inhibiting drugs appear to be readily absorbed by cells without the need for a separate delivery vehicle. The company has been targeting an miRNA called miR-122, which is thought to regulate up to 450 genes, around 100 of which are involved in cholesterol and lipid metabolism. It is only expressed in liver cells.

Santaris created short, single-stranded RNA molecules designed to bind specifically to miR-122 and injected them into mice. This miRNA inhibitor, or antimiR, was readily taken up by liver cells and lowered cholesterol by up to 35 per cent. Inhibiting miR-122 also seems to protect the liver against hepatitis C infection, tests on cell cultures suggest.

Technorati tags: gene therapy, rna interference

SKorea's LG Philipps develops first A4 colour e-paper

SKorea's LG Philipps develops first A4 colour e-paper

The e-paper -- which measures 14.1 inches (35.9 centimetres) across its diagonal and is just 300 micrometres (0.3 millimetres) thin -- can display up to 4,096 colours, the world's second largest liquid crystal display maker said in a statement.

It is designed to be energy-efficient, only using power when the image changes on the display, it said.

"This represents the next generation in display technology," Chung In-Jae, chief technology officer and executive vice president, said in the statement.

The new display product's potential applications "are incredible and will allow our customers to create new products that are not only convenient to use but also save natural resources," he added.

LG Philips said it developed the world's first 10.1-inch flexible black-and-white e-paper in October 2005 and a 14.1-inch follow-up -- which matches the most common copy size -- in May 2006.

Technorati tags: electronic paper

Scientists one more step closer to realising invisible technology

Scientists one more step closer to realising invisible technology

Scientists have already created an ‘invisibility cloak’ made out of ‘metamaterial’ which can bend electromagnetic radiation – such as visible light, radar or microwaves – around a spherical space, making an object within this region appear invisible.

Until now, scientists could only make objects appear invisible from far away. Liverpool mathematician Dr Sébastien Guenneau, together with Dr Frédéric Zolla and Professor André Nicolet from the University of Marseille, have proven - using a specially designed computer model called GETDP - that objects can also be made to appear invisible from close range when light travels in waves rather than beams.

Scientists predict that metamaterials could be of use in military technology, such as in the construction of fighter jets and submarines, but it will be some years before invisibility cloaks can be developed for human beings.

Dr Guenneau, at the University’s Department of Mathematical Science, explains:

“The shape and structure of aeroplanes make them ideal objects for cloaking, as they have a fixed structure and movement pattern. Human beings and animals are more difficult as their movement is very flexible, so the cloak - as it is designed at the moment - would easily be seen when the person or animal made any sudden movement.

“A cloak, such as the one worn by the Harry Potter character for example, is not yet possible but it is a good example of what we are trying to move towards. Using this new computer model we can prove that light can bend around an object under a cloak and is not diffracted by the object. This happens because the metamaterial that makes up the cloak stretches the metrics of space, in a similar way to what heavy planets and stars do for the metrics of space-time in Einstein’s general relativity theory.

“In order for the cloaking device to work in the first place light has to separate into two or more waves resulting in a new wave pattern. Within this pattern we get light and dark regions which are needed in order for an object to appear invisible.

“Until now, however, it was not clear whether photons – particles that make up all forms of light – can split and form new waves when the light source is close to the object. If we use ray optic techniques – where light travels in beams - photons break down at close range and the object does not appear invisible. If we study light as it travels in waves however, invisibility is maintained.”

Scientists predict that invisibility will be possible for objects of any shape and size within the next decade.

The research findings are published in Optic Letters.

Technorati tags: mathematics, invisibility

Microelectronics | Growing up | Economist.com

Microelectronics | Growing up | Economist.com

Long, thin transistors made of silicon nanowires may be the next contribution to electronic miniaturisation

THE race in computing is a race to the bottom. The need is always to cram more components on to less “real estate”. And, like real-estate developers in the more familiar world of human cities, there comes a point where “up” seems like a good alternative to urban sprawl.

That is the thinking behind making transistors out of nanowires. The wires in question—strands of silicon—are but a few tens of nanometres thick. Though they make up for that in height (they are 2,000 nanometres tall). Their slight diameters mean that zillions of them could be crowded on to a single chip.

Those diameters are, indeed, so slight that the wires are essentially one-dimensional. That gives them interesting properties. It is much easier for electrons to pass through them than through three-dimensional wires, for two reasons. One is that there is less leeway for the electrons to scatter simply because there is less room for them to manoeuvre. The second is that the atomic surface of nanowires tends to be smoother than that of regular wires because the former are perfect crystals. That also reduces scattering

Walter Riess, a physicist at IBM’s Zurich Research Laboratory, in Switzerland, and his colleagues wanted to exploit these features to make better transistors. A transistor is, at bottom, just a switch that allows or prohibits the passage of one electric current according to instructions carried by a second current. What Dr Riess’s team has done is to make silicon nanowires switch on and off like a transistor.

Researchers discover first gene that specifically links calorie restriction to longevity

Researchers discover first gene that specifically links calorie restriction to longevity:

Now, researchers at the Salk Institute for Biological Studies have cracked open the black box of how persistent hunger promotes long life and identified a critical gene that specifically links calorie restriction (CR) to longevity.

“After 72 years of not knowing how calorie restriction works, we finally have genetic evidence to unravel the underlying molecular program required for increased longevity in response to calorie restriction,” says Andrew Dillin, Ph.D., an associate professor in the Molecular and Cell Biology Laboratory, who led the study published online in the May 2 issue of Nature.

Having identified a key link between calorie restriction and aging also opens the door to development of drugs that mimic the effects of calorie restriction and might allow people to reap health benefits without adhering to an austere regimen that only ascetics can endure.

Technorati tags: longevity