Physics & Mathematics

Optical trap provides new insights into motor molecules

When it comes to nanotechnology, many researchers turn to nature for inspiration. Of particular interest to nanoengineers is the naturally occurring protein kinesin – one of several ”motor molecules” that facilitate movement in living cells. A mere ten-millionth of an inch long, kinesin is the workhorse of the cell, hauling chromosomes, neurotransmitters and other vital cargo along tiny tracks called ”microtubules.” While one end of a kinesin molecule holds onto its cargo, the other end uses a strange two-headed structure to grab the microtubule and pull the cargo forward.

Cables could help protect buildings from bombs

Securing steel cables around the floors of existing buildings may be an effective way to prevent a catastrophic collapse caused by a terrorist bomb, according to test results released by researchers at the University of California, Berkeley.
Abolhassan Astaneh-Asl, professor of civil engineering at UC Berkeley’s College of Engineering, and four of his civil engineering graduate students have successfully tested a system that would shift the gravity load of a collapsing floor to supporting cables if a column were destroyed by a natural disaster, such as an earthquake, or a terrorist bomb.

Rivers of gas could provide part of universe's 'missing matter'

An Ohio astronomer and her colleagues have detected a type of hot gas in space that could account for part of the “missing” matter in the universe. A gas cloud, one trillion times more massive than our sun and more than 150 times hotter, surrounds our local group of galaxies, the astronomers reported in the journal Nature. Though vast, this gas cloud is only part of larger rivers of gas that wind between all the galaxies of the universe.

New Molecular Self-Assembly Technique May Mimic How Cells Assemble Themselves

Researchers report that they have created tree-like molecules that assemble themselves into precisely structured building blocks of a quarter-million atoms. Such building blocks may be precursors to designing nanostructures for molecular electronics or photonics materials, which “steer” light in the same way computer chips steer electrons.

Case for Massive Black Hole Strengthened

UCLA astronomer Andrea Ghez announced more than four years ago that a monstrous black hole resides at the center of our Milky Way galaxy, 24,000 light years away, with a mass more than 2 million times that of our sun. Some astronomers greeted the announcement with skepticism, and proposed exotic forms of matter as alternatives. At the American Association for the Advancement of Science meeting Feb. 16 in Denver, Ghez reported that the case for the black hole has been strengthened substantially, and that all of the proposed alternatives can be excluded.

Mission Reveals End of Universe's 'Dark Ages,'Fate of Universe and Dark Matter

The universe had a period of “Dark Ages,” starting approximately half-a-million years after the Big Bang, and NASA’s Wilkinson Microwave Anisotropy Probe (WMAP) has revealed the end of the Dark Ages. “We detected the end of the Dark Ages about 200 million years after the Big Bang,” said Edward L. Wright, professor of astronomy at UCLA, who helped develop key data analysis techniques for WMAP. “There were enough bright stars and quasars at that time to fill the universe with ultraviolet light and a haze of cosmic electrons. This is nearly 700 million years earlier than any of these objects has been seen before. WMAP measurements have enabled us to detect the era when the first stars formed.”

Students discover new class of star

Astronomy undergraduates have serendipitously discovered a new class of star that thrills astronomers who specialize in a relatively new field called “asteroseismology.” Astronomers worldwide will collaborate in continuous observations of one of these newly found stars for several weeks in May 2003. “Astronomers are always looking for new and better ways to study stars,” said Elizabeth Green, University of Arizona assistant staff astronomer at Steward Observatory, who with her students discovered the new class of stars. They have found sub-dwarf B stars that pulsate like Jell-O, quivering in space through cycles that typically last an hour.

Researchers develop 'natural bandages' that mimic body's healing process

With the same compound the body uses to clot blood, scientists at Virginia Commonwealth University have created a nano-fiber mat that could eventually become a “natural bandage.” Spun from strands of fibrinogen 1,000 times thinner than a human hair, the fabric could be placed on a wound and never taken off — minimizing blood loss and encouraging the natural healing process.

'Sticky' DNA crystals promise new way to process information

Imagine information stored on something only a hundredth the size of the next generation computer chip–and made from nature’s own storage molecule, DNA. A team led by Richard Kiehl, a professor of electrical engineering at the University of Minnesota, has used the selective “stickiness” of DNA to construct a scaffolding for closely spaced nanoparticles that could exchange information on a scale of only 10 angstroms (an angstrom is one 10-billionth of a meter). The technique allows the assembly of components on a much smaller scale and with much greater precision than is possible with current manufacturing methods, Kiehl said. The work is published in a recent issue of the Journal of Nanoparticle Research.

New Genetic 'Fishing Net' Harvests Elusive Autism Gene

Researchers have developed a new statistical genetic “fishing net” that they have cast into a sea of complex genetic data on autistic children to harvest an elusive autism gene.
Moreover, the researchers said that the success of the approach will be broadly applicable to studying genetic risk factors for other complex genetic diseases, such as hypertension, diabetes and multiple sclerosis. In this case, the gene, which encodes part of a brain neurotransmitter docking station called the gamma-Aminobutyric Acid Receptor beta3-subunit (GABRB3), has been implicated in autism previously, but never positively linked to the disease. Their findings will be published in the March 2003 issue of the American Journal of Human Genetics.