Author: Madhu Reddy

The brain waves that result in response to certain words could be used to verify a person’s identity

Passwords are the bane of many a computer user’s existence. Experts recommend long strings of characters containing a mix of upper and lowercase letters, numbers and symbols that may be difficult to crack, but can also be difficult to remember. Despite there being simple techniques for creating difficult-to-crack passwords that are easy to remember and horror stories of identify theft abound, the top two most common passwords remain “12345” and “password”. But a study out of Binghampton University (BU) in New York suggests brainwaves could be a promising alternative to verify a user’s identity.

Researchers at BU read a list of 75 acronyms, such as FBI and DVD, to 45 volunteers and observed the brainwaves that resulted from each group of letters, focusing on the part of the brain associated with reading and recognizing words. This was done with the placement of just three electrodes on the scalp, which is the minimum number that can be used and still obtain a clean reading.

While each respondent’s brainwaves exhibited identifiable features that were consistent in response to a given acronym, the reactions – or “brainprints” – were different enough between respondents to allow a computer system to identify each volunteer with an accuracy of 94 percent. These results were also stable over time, with identification possible after a lag of up to six months.

Sarah Laszlo, assistant professor of psychology and linguistics at BU and study co-author, says that brain biometrics offer a number of advantages over other physical characteristics used for biometrics, such as fingerprints or retinas. For example, both of these can be stolen by malicious means, rendering them unusable by the user since they can’t be replaced.

“If someone’s fingerprint is stolen, that person can’t just grow a new finger to replace the compromised fingerprint – the fingerprint for that person is compromised forever,” points out Laszlo. “Fingerprints are ‘non-cancellable.’ Brainprints, on the other hand, are potentially cancellable. So, in the unlikely event that attackers were actually able to steal a brainprint from an authorized user, the authorized user could then ‘reset’ their brainprint.”

While the researchers don’t see brainprints as a potential replacement for passwords for low security applications in the near future – after all, who wants to hook themselves up to an electroencephalograph (EEG) just to log into their email – they do see the technology having potential in high security environments.

“We tend to see the applications of this system as being more along the lines of high-security physical locations, like the Pentagon or Air Force Labs, where there aren’t that many users that are authorized to enter, and those users don’t need to constantly be authorizing the way that a consumer might need to authorize into their phone or computer,” says Zhanpeng Jin, assistant professor at Binghamton University’s departments of Electrical and Computer Engineering, and Biomedical Engineering.

The team’s study appears in the journal Neurocomputing.

References:http://www.gizmag.com/

The decellularized rat forelimb is injected with muscle and vascular cells

Currently, recipients of arm or leg transplants need to take immunosuppressive drugs for the rest of their lives, in order to keep the donated parts from being rejected. If we could grow our own replacement limbs, however, that wouldn’t be necessary. And while we do already possess the progenitor cells needed to grow such parts, what’s been lacking is a method of assembling them into the form of the desired limb. Now, however, scientists have created a shortcut of sorts – they’ve stripped the cells from one rat’s forelimb and replaced them with live cells from another rat, creating a functioning limb that the second rat’s immune system won’t reject.

Led by Dr. Harald Ott, a team at the Massachusetts General Hospital started by perfusing the donor limb with a detergent that stripped away all of its living cells. After the cellular debris was removed, all that remained was the empty non-living extracellular matrix that formerly contained the cells.

As this task was in process, progenitor cells from the recipient rat were being being grown in culture to produce muscle and vascular cells.

Once the limb was stripped of its original cells, it was placed in a nutrient solution-filled bioreactor and injected with the lab-grown cells – the muscle cells went into the individual muscle sheath sections of the matrix, while the vascular cells went into the main artery. After five days of being in the reactor, electric stimulation was applied to help the muscles grow. Two weeks later, upon being removed from the reactor, the limb was found to have functioning muscle cells in the muscle fibers and live vascular cells in the blood vessel walls.

When the muscles were activated using electrical stimulation, they were found to have 80 percent the strength of a newborn rat’s forelimb muscles. Additionally, when the limb was transplanted onto the recipient rat, its blood vessels soon filled with blood and became part of the circulatory system.

Ott and his team are now looking at ways of regrowing other limb tissues such as bone, cartilage and connective tissue. The regrowth of nerves should hopefully happen on its own. “In clinical limb transplantation, nerves do grow back into the graft, enabling both motion and sensation, and we have learned that this process is largely guided by the nerve matrix within the graft,” he says. “We hope in future work to show that the same will apply to bioartificial grafts.”

The decellularization technique utilized by the Massachusetts scientists, incidentally, has previously been used to create transplantable mouse hearts and rat kidneys. However, this is the first time that it’s been used for something more complex than an organ. The scientists have also decellularized a baboon forearm, indicating that the procedure could work on primates.

References:http://www.gizmag.com/

A new almost–universal SERS substrate could be the key to cheaper and easier sensors for drugs, explosives, or anything else (Credit: University of Buffalo)

Identifying fraudulent paintings based on electrochemical data, highlighting cancerous cells in a sea of healthy ones, and identifying different strains of bacteria in samples of food are all examples of surface-enhanced Raman spectroscopy (SERS), a sensor system that has only become more in-demand as our desire for precise, instantaneous information has increased. However, the technology has largely failed commercialization because the chips used are difficult and expensive to create, have limited uses for a particular known substance, and are consumed upon use. Researchers led by a team from the University of Buffalo (UB) aim to change nanoscale sensors with an almost-universal substrate that’s also low-cost, opening up more opportunities for powerful analysis of our environment.

Though SERS is complicated to understand on the surface, it forms a critical part of testing for explosives, identifying toxins in food, and other applications in public health and safety, medicine, and research.

The technique relies on the unique electromagnetic properties of chemical compounds when stimulated with varying wavelengths of laser light and interacting with a surface designed to enhance the response (the “surface” in the name SERS). Each unique compound has a distinct spectral fingerprint and thus an industry researcher can discern between compounds that are invisible to the human eye without having to rely on doping the sample with labeling chemicals or having to possess a large sample.

Yet, currently most surfaces or substrates available on a commercial chip are optimized for only one wavelength of light, meaning scientists working with multiple compounds may need several chips to identify all their samples. This also ignores the ability to identify anonymous samples, which by their nature would require testing on multiple substrates.

The research from the team from UB and Fudan University in China introduces a substrate with a broadband nanostructure that “traps” the wide range of light most often used in SERS analysis, between 450 and 1100 nm.

The surface is composed of a film of thin silver or aluminum acting as a mirror, and a dielectric silica or alumina layer which separates the “mirror” from a layer of randomly applied silver nanoparticles. This construction also avoids expensive lithographic construction techniques.

Researcher Nan Zhang summed up the importance of the design by comparing it to a skeleton key.

“Instead of needing all these different substrates to measure Raman signals excited by different wavelengths, you’ll eventually need just one,” says Zhang. “Just like a skeleton key that opens many doors.”

Perhaps soon these “keys” will be available for airport screening, counterfeit protection, chemical weapon detection and a host of many more purposes requiring flexible, cheap sensors.

“The applications of such a device are far-reaching,” said Kai Liu, a PhD candidate in electrical engineering at UB. “The ability to detect even smaller amounts of chemical and biological molecules could be helpful with biosensors that are used to detect cancer, Malaria, HIV and other illnesses.”

References:http://www.gizmag.com/