Physicists measure spin of a single atom
BERKELEY, Calif., Sept. 12 (UPI) -- U.S. physicists have succeeded in measuring the spin of a single atom, thereby bringing quantum computers and spintronic devices closer to reality.
Researchers striving to shrink computers to the nanoscale consider atomic spin as one possible building block for both processor and memory. But scientists say setting the spin of an atom, let alone measuring it, has been a challenge.
Now, University of California-Berkeley physicists have succeeded in measuring the spin of a single atom, moving one step closer to building nanoscale transistors based on atomic spin.
"From a technical point of view, this demonstrates a new ability to engineer, fabricate and measure spin-polarized nanostructures at the single atom level," said University of California-Berkeley physics Professor Michael Crommie. "Now that I can see an atom's spin, I can ask 'What can I do with that atomic spin? Can I manipulate it? Can I use it, change it?' This means we can now start incorporating it into other structures."
Crommie and his colleagues at UC Berkeley and the Naval Research Laboratory in Washington, D.C., recently reported their success in the journal Physical Review Letters.
Possible Chlamydia vaccine target found
PITTSBURGH, Sept. 12 (UPI) -- U.S. scientists have identified a potential target for a vaccine to fight Chlamydia -- the world's most prevalent sexually transmitted bacterial infection.
Researchers at the University of Pittsburgh Medical Center's Children’s Hospital, led by Dr. Toni Darville, identified a plasmid-deficient strain of Chlamydia trachomatis that, when investigated in an animal model of genital tract infection, failed to cause disease. Plasmids are small molecules of DNA.
"This finding represents a major step forward in our work to eventually develop a vaccine against chlamydial disease," said Darville, a professor of pediatrics and microbiology/immunology. "If we can identify plasmid-deficient derivatives of the C. trachomatis strains that infect humans, they would have the potential to serve as a vaccine against this disease."
The study is reported in the Journal of Immunology.
Opportunity enters Mars' Victoria Crater
PASADENA, Calif., Sept. 12 (UPI) -- NASA's Mars Exploration Rover Opportunity entered Victoria Crater for the first time, reporting its information via the Mars Odyssey orbiter.
National Aeronautics and Space Administration mission scientists at the Jet Propulsion Laboratory in Pasadena, Calif., said Opportunity moved about 13 feet into the crater Tuesday -- just enough to position all of its six wheels inside the crater rim. It then backed uphill for about 10 feet.
Rover Project Manager John Callas said the driving commands included a precaution for the rover to stop moving if its wheels were slipping more than 40 percent. Slippage exceeded that amount on the last step of the drive, so Opportunity stopped with its front pair of wheels still inside the crater.
"We will do a full assessment of what we learned from the drive … and use that information to plan Opportunity's descent into the crater," said Callas.
The exploration is designed to investigate layered rocks exposed on the crater's interior slope that might reveal evidence of interaction between the Martian atmosphere and surface from millions of years ago, when the planet's atmosphere might have been different from present conditions.
Better, cost-effective respirators studied
CAMBRIDGE, Mass., Sept. 12 (UPI) -- U.S. scientists said the human body's ability to adapt to recurring stimuli might be used to design more effective, inexpensive artificial respirators.
Massachusetts Institute of Technology researchers said such an approach could minimize the need for induced sedation or paralysis currently necessary for some patients to use mechanical ventilation.
Existing respirators don't consider the adaptive nature of breathing in their design; some ignore a patient's natural rhythm and pump air in and out of the lungs on set intervals. As a result, physicians often must sedate or paralyze patients to prevent them from fighting an unfamiliar rhythm. Other respirators that are designed to rely on the patient to trigger the airflow are costly and tend to be unreliable for weak patients, such as newborns or those in critical care.
The MIT research suggested, however, that if a doctor takes the patient's natural breathing rhythm into account and sets the ventilator's rhythm in that same range, the patient will adapt and synchronize with the ventilator.
The study by Chi-Sang Poon and Gang Song of the Harvard-MIT Division of Health Sciences and Technology and Shawna MacDonald of MIT's mechanical engineering department appears in the online journal PLoS One.
