Using classical coding, a single photon will convey only one of two messages - one bit of information. In dense coding, a single photon can convey one of four messages - two bits of information.

University of Illinois researchers say they have broken the record for the most amount of information sent by a single photon using the direction of “wiggling” and “twisting” of a pair of hyper-entangled photons. Doing so, they have beaten a fundamental limit on the channel capacity for dense coding with linear optics.

“Dense coding is arguably the protocol that launched the field of quantum communication,” said Paul Kwiat, a John Bardeen Professor of Physics and Electrical and Computer Engineering. “Today, however, more than a decade after its initial experimental realization, channel capacity has remained fundamentally limited as conceived for photons using conventional linear elements.”

Chemists at the University of California, San Diego have discovered that a chemical reaction in the atmosphere above major cities long assumed to be unimportant in urban air pollution is in fact a significant contributor to urban ozone—the main component of smog.

Their finding should help air quality experts devise better strategies to reduce ozone for US areas that exceed new standards announced last week by the Environmental Protection Agency and also benefit cities like Mexico City and Beijing that are grappling with major air quality and urban smog problems. More than 100 million people worldwide currently live in cities that fail to meet international standards for air quality.

Graphene, a single-atom-thick sheet of graphite, is a new material which combines aspects of semiconductors and metals.

University of Maryland physicists have shown that in graphene the intrinsic limit to the mobility, a measure of how well a material conducts electricity, is higher than any other known material at room temperature - and 100 times faster than in silicon.

A team of researchers led by physics professor Michael S. Fuhrer of the university's Center for Nanophysics and Advanced Materials, and the Maryland NanoCenter said the findings are the first measurement of the effect of thermal vibrations on the conduction of electrons in graphene, and show that thermal vibrations have an extraordinarily small effect on the electrons in graphene.

In baseball's golden age, pitchers had a higher mound and threw more complete games but careers were shorter. As salaries continue to rise there is greater concern about protecting the investments. A new study involving several Major League Baseball pitchers indicates that the height of the pitcher’s mound can affect the athlete’s throwing arm motion, which may lead to potential injuries because of stress on the shoulder and elbow.

The study was led by William Raasch, M.D., associate professor of orthopaedic surgery at the Medical College of Wisconsin in Milwaukee, who also is the head team physician for the Milwaukee Brewers. Major League Baseball funded the study in an effort to help prevent injuries among professional baseball players.

Since robots live in a binary world, it is difficult to program them in a way where they can understand the nuances and inflections of human speech among many different people.

A team of researchers from the Georgia Institute of Technology and Emory University may have made that unnecessary. They can instruct a robot to find and deliver things using something more direct than speech - a laser pointer.

El-E (pronounced like the name Ellie), a robot designed to help users with limited mobility with everyday tasks, autonomously moves to an item selected with a green laser pointer, picks up the item and then delivers it to the user, another person or a selected location such as a table. El-E, named for her ability to elevate her arm and for the arm's resemblance to an elephant trunk, can grasp and deliver several types of household items including towels, pill bottles and telephones from floors or tables.

In research that could lead to the prevention of up to one-fifth of birth defects in humans caused by genetic mutations, early stage fish embryos injected with a 'genetic patch' were able to develop normally.

Erik C. Madsen, Ph.D. student in the Medical Scientist Training Program at Washington University School of Medicine, made the discovery using a zebrafish model of Menkes disease, a rare, inherited disorder of copper metabolism caused by a mutation in the human version of the ATP7A gene. Zebrafish are vertebrates that develop similarly to humans, and their transparency allows researchers to observe embryonic development.