World’s most precise clock

Imagine a clock precise to one second in a period comparable to the age of the universe (more than 13 billion years).

That’s what National Institute of Standards and Technology (NIST) scientists have built, with funding from DARPA’s Quantum-Assisted Sensing and Readout (QuASAR) program: two optical lattice clocks that use ultracold ytterbium atoms to measure the passage of time.

The ytterbium clocks tick off seconds by measuring the frequency of light absorbed by atoms as electrons in the ground state jump to an excited state. Each of the clocks relies on approximately 10,000 rare-earth ytterbium atoms cooled to ten millionths of a degree above absolute zero and trapped in an optical lattice made of laser light.

Another laser provides the resonant energy necessary for the atoms to cycle between two energy levels a rate of 518 trillion times per second (518 terahertz), achieving timekeeping precision of one part in 1018.

That’s 10,000 times better than the current atomic clocks used to support GPS satellites. This extreme stability could vastly extend the time between GPS clock updates and may block attempts by an adversary to spoof GPS signals.

Such clock precision could also enable more precise methods to measure gravity, magnetic fields, and temperature.

http://www.darpa.mil/NewsEvents/Releases/2013/08/29.aspx

‘Biological resynchronization’: stem cells keep cardiac beat in synchrony

The team proposes a novel strategy of “biological resynchronization” in which stem cells repair heart muscle damage to reestablish correct cardiac motion, replacing pacing devices,

Heart attacks limit local oxygen, which can kill areas of cardiac tissue — called ‘infarcted’ areas — and also leave scarring. This damage leads to a lack of synchrony in the heart beat motion.

http://www.alphagalileo.org/ViewItem.aspx?ItemId=133950&CultureCode=en

Microencapsulation produces uniform drug release vehicle

Consistently uniform, easily manufactured microcapsules containing a brain cancer drug may simplify treatment and provide more tightly controlled therapy, according to Penn State researchers.

“Brain tumors are one of the world’s deadliest diseases,” said Mohammad Reza Abidian, assistant professor of bioengineering, chemical engineering and materials science and engineering. “Typically doctors resect the tumors, do radiation therapy, and then chemotherapy.”

The majority of chemotherapy is done intravenously, but, because the drugs are very toxic and are not targeted, they have a lot of side effects. Another problem with intravenous drugs is that they go everywhere in the bloodstream and do not easily cross the blood brain barrier so little gets to the target tumors. To counteract this, high doses are necessary.

Microcapsules to precisely control drug release

“We are trying to develop a new method of drug delivery,” said Abidian. “Not intravenous delivery, but localized directly into the tumor site.”

http://www.eurekalert.org/pub_releases/2013-09/ps-mpu082913.php

Creating a low-cost, flexible touchscreen

Future touchscreens* will be flexible, cheap, and give you finer touch-control.

The secret: replace currently used indium tin oxide (ITO) — which is expensive, rare, and worse, brittle — with cheap, flexible metal nanowires that can even be sprayed on.

Unfortunately, there has been no simple way to design a touchscreen using nanowires that will provide an optimum combination of low resistance, evenness, and transparency.

It’s trial-and-error: create a batch with a new wire aspect ratio (length/diameter), density, etc., percolate it (like filtering coffee), and see if the thing works — or just forms a random network with gaps. Frustrating, slow.

Now researchers at the University of Pennsylvania** and Duke University** have developed a clever workaround: computer simulation of various combinations of nanowire length and diameter, the number of nanowires, the area they cover, and contact resistance (at wire connections) to reach the Goldilocks zone: the optimum combination of electrical properties and transparency.

No information on commercialization of this research was available from the team, but future research will focus on nanowire orientation, various continuous deposition methods, variation in nanowire length and diameter, and different processing techniques.

The research was supported by the National Science Foundation and Penn’s Materials Science Research and Engineering Center.

http://www.upenn.edu/pennnews/news/penn-develops-computer-model-will-help-design-flexible-touchscreens

A new supercapacitor for energy storage at high temperatures

Rice University researchers who have developed a supercapacitor that can operate at very high temperatures, using clay as a key ingredient.

The supercapacitor is reliable at temperatures of up to 200 degrees Celsius (392 degrees Fahrenheit), and could be useful for powering devices for use in extreme environments, such as oil drilling, the military and space, Rice scientist Pulickel Ajayan reported in Nature’s online journal, Scientific Reports (open access),

“Our intention is to completely move away from conventional liquid or gel-type electrolytes, which have been limited to low-temperature operation of electrochemical devices,” said Arava Leela Mohana Reddy, lead author and a former research scientist at Rice.

“By allowing safe operation over a wide range of temperatures without compromising on high energy, power and cycle life, we believe we can dramatically enhance or even eliminate the need for expensive thermal management systems.”

A supercapacitor combines the best qualities of capacitors that charge in seconds and discharge energy in a burst and rechargeable batteries that charge slowly but release energy on demand over time. The ideal supercapacitor would charge quickly, store energy and release it as needed.

“Researchers have been trying for years to make energy storage devices like batteries and supercapacitors that work reliably in high-temperature environments, but this has been challenging, given the traditional materials used to build these devices,” Ajayan said.

http://news.rice.edu/2013/09/03/clay-key-to-high-temperature-supercapacitors/

Cancer’s origins revealed

Researchers at Wellcome Trust Sanger Institute have provided the first comprehensive compendium of mutational processes that drive tumor development. Together, these mutational processes explain most mutations found in 30 of the most common cancer types. This new understanding of cancer development could help to treat and prevent a wide-range of cancers.

Each mutational process leaves a particular pattern of mutations, an imprint or signature, in the genomes of cancers it has caused. By studying 7,042 genomes of people with the most common forms of cancer, the team uncovered more than 20 signatures of processes that mutate DNA. For many of the signatures, they also identified the underlying biological process responsible.

All cancers are caused by mutations in DNA occurring in cells of the body during a person’s lifetime. Although we know that chemicals in tobacco smoke cause mutations in lung cells that lead to lung cancers and ultraviolet light causes mutations in skin cells that lead to skin cancers, we have remarkably little understanding of the biological processes that cause the mutations which are responsible for the development of most cancers.

https://www.sanger.ac.uk/about/press/2013/130814.html

How DNA repair helps prevent cancer

The biological information that makes us unique is encoded in our DNA. DNA damage is a natural biological occurrence that happens every time cells divide and multiply. External factors such as overexposure to sunlight can also damage DNA.

Michael Feig, professor of biochemistry and molecular biology at Michigan State University, studies the proteins MutS and MSH2-MSH6, which recognize defective DNA and initiate DNA repair. Natural DNA repair occurs when proteins like MutS (the primary protein responsible for recognizing a variety of DNA mismatches) scan the DNA, identify a defect, and recruit other enzymes to carry out the actual repair.

“The key here is to understand how these defects are recognized,” Feig explained. “DNA damage occurs frequently and if you couldn’t repair your DNA, then you won’t live for very long.” This is because damaged DNA, if left unrepaired, can compromise cells and lead to diseases such as cancer.

http://pubs.acs.org/doi/abs/10.1021/jp403127a

NSA cracks most Internet encryption, inserts back doors, The New York Times reveals

The NSA has circumvented or cracked much of the encryption, or digital scrambling, that guards global commerce and banking systems, protects sensitive data like trade secrets and medical records, and automatically secures the e-mails, Web searches, Internet chats, and phone calls of Americans and others around the world, The New York Times reports

The agency, according to documents provided to The Times and ProPublica by Edward J. Snowden and interviews with industry officials:

Deployed custom-built, superfast computers to break codes

Collaborated with technology companies in the United States and abroad to build in back doors

Coerced some companies into handing over their master encryption keys or building in a back door

Covertly introduced weaknesses into the encryption standards followed by hardware and software developers, or altered their software or hardware.

Worked with chipmakers to insert back doors or by exploiting security flaws

Had partnerships with major telecommunications carriers

Had access to Microsoft’s most popular services, including Outlook e-mail, Skype Internet phone calls and chats, and SkyDrive, the company’s cloud storage service.

Cracked enryptions of Secure Sockets Layer (SSL); virtual private networks (VPNs), and the protection used on 4G smartphones

Accessed the world’s fiber optic cables and Internet hubs

https://www.nytimes.com/2013/09/06/us/nsa-foils-much-internet-encryption.html?pagewanted=all&_r=0

DNA-based biological nanostructures for controlled drug delivery

Nanoscale “cages” made from strands of DNA can encapsulate small-molecule drugs and release them in response to a specific stimulus, McGill University researchers report in a new study.

The research marks a step toward the use of biological nanostructures to deliver drugs to diseased cells in patients.

The findings could also open up new possibilities for designing DNA-based nanomaterials.

“This research is important for drug delivery, but also for fundamental structural biology and nanotechnology,” says McGill Chemistry professor Hanadi Sleiman, who led the research team.

In their experiments, the McGill researchers first created DNA cubes using short DNA strands, and modified them with lipid-like molecules. The lipids can act like sticky patches that come together and engage in a “handshake” inside the DNA cube, creating a core that can hold cargo such as drug molecules.

http://www.newswise.com/articles/dna-cages-may-aid-drug-delivery

‘Seeing’ faces through touch

Perceiving faces can be enhanced by touch, says researcher Kazumichi Matsumiya of Tohoku University in Japan.

The face aftereffect

In a series of studies, Matsumiya took advantage of a phenomenon called the “face aftereffect” to investigate whether our visual system responds to nonvisual signals for processing faces.

In the face aftereffect, we adapt to a face with a particular expression — happiness, for example — which causes us to perceive a subsequent neutral face as having the opposite facial expression (i.e., sadness).

Matsumiya hypothesized that if the visual system really does respond to signals from another modality, we should see evidence for face aftereffects from one modality to the other. So, adaptation to a face that is explored by touch should produce visual face aftereffects.

The experiment

To test this, Matsumiya had participants explore face masks concealed below a mirror by touching them. After this adaptation period, the participants were visually presented with a series of faces that had varying expressions and were asked to classify the faces as happy or sad. The visual faces and the masks were created from the same exemplar.

In line with his hypothesis, Matsumiya found that participants’ experiences exploring the face masks by touch shifted their perception of the faces presented visually compared to participants who had no adaptation period, such that the visual faces were perceived as having the opposite facial expression.

Further experiments ruled out other explanations for the results, including the possibility that the face aftereffects emerged because participants were intentionally imagining visual faces during the adaptation period.

And a fourth experiment revealed that the aftereffect also works the other way: Visual stimuli can influence how we perceive a face through touch.