A destructive spring freeze that chilled the eastern United States almost a year ago illustrates the threat a warming climate poses to plants and crops, according to a paper just published in the journal BioScience. The study was led by a team from the Department of Energy's Oak Ridge National Laboratory.

The "Easter freeze" of April 5-9, 2007, blew in on an ill wind. Plants had been sending out young and tender sprouts two to three weeks earlier than normal during an unusually warm March. Plant ecologists, as well as farmers and gardeners, took note of the particularly harsh turn of the weather in early April.

"The warm weather was as much a culprit for the damage as the cold," said lead author Lianhong Gu of ORNL's Environmental Sciences Division.

Modern diesel cars are quieter than their predecessors but also release considerably fewer exhaust fumes into the atmosphere.

But the real culprit in diesel are heavy-duty, construction and off-road vehicles - they're often special vehicles made in small batches and each requires a different filter geometry. The filters for are not yet state-of-the-art. A new diesel particulate filter technology will soon teach even these vehicles to give up smoking.

Conventional diesel soot filters usually consist of cylindrical ceramic blocks crisscrossed by numerous channels. A block of this kind cannot be made in one piece. Instead, individual quadratic honeycomb segments are bonded together to form a large block.

The RoboSwift micro-aircraft has made its first flight. The small, quiet plane is equipped with observation cameras that can be used in the future to study birds or to conduct surveillance of groups of people or vehicles.

The RoboSwift is characterised by the continuously variable shape of its wings, known as ‘morphing' wings, which are modelled on the wings of the swift bird. These wings make the aircraft, like its living model, very maneuverable and efficient. As a result, the RoboSwift is the first aircraft in the world to have the wing properties of living birds. Wind tunnel tests have shown that it can come remarkably close to the exceptional flying ability of the swift.

A combination of negative mother-daughter relationships and low blood levels of serotonin, an important brain chemical for mood stability, may be lethal for adolescent girls, leaving them vulnerable to engage in self-harming behaviors such as cutting themselves.

New University of Washington research indicates that these two factors in combination account for 64 percent of the difference among adolescents, primarily girls, who engage in self-harming behaviors and those who do not.

“Girls who engage in self harm are at high risk for attempting suicide, and some of them are dying,” said Theodore Beauchaine, a UW associate professor of psychology and co-author of a new study. “There is no better predictor of suicide than previous suicide attempts.”

Solving a long-standing biological mystery, UCLA stem cell researchers have discovered that blood stem cells, the cells that later differentiate into all the cells in the blood supply, originate and are nurtured in the placenta.

The discovery may allow researchers to mimic the specific embryonic microenvironment necessary for development of blood stem cells in cell culture and grow them for use in treating diseases like leukemia and aplastic anemia, said Dr. Hanna Mikkola, a researcher in the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research and senior author of the study.

People who handle explosives usually have heavy-duty tasks to perform – dislodging rocks, demolishing old buildings, or triggering an avalanche. Now explosives can be used for delicate tasks, too, like making it possible to place holograms in steel.

Nearly everybody carries holograms around on light things, like money or tickets for a concert, because they protect against forgery. They take a great deal of effort to produce, and are almost impossible to copy, because the image is created not only by the interaction of different colors and contrasts, but also by the surface structure. Different pictures can be seen, depending on the direction from which the light is shining.