PROTEINS HELP CELLS MOVE
Researchers at Yale and the Salk Institute have determined the structure of a set of proteins called the Arp2/3 complex that helps cells move, paving the way for understanding how cells find bacteria and protect against infections. "This is a dream come true to see the structure of this important protein complex in such detail," says Thomas Pollard. The study, published in Science, describes the atomic structure of the Arp2/3 complex for the first time. "Knowledge of the three-dimensional structure not only provides key insights about Arp2/3 complex, but it will also elevate the level of research on cellular movements for years to come," Pollard says. The complex is made up of seven different proteins and is responsible for initiating the assembly of the protein actin into filaments at the front end of a moving cell. This growth of actin filaments is called polymerization and is believed to push the front of the cell forward, allowing it to move. Pollard says the classic example of such movements is the locomotion of amoeba. Many human cells rely on the same mechanism.
CONCEIVING BABIES TO SAVE SIBLINGS BENEFICIAL
Using preimplantation genetic diagnosis (PGD) to choose a stem cell donor is unlikely to cause harm to anyone and is likely to be beneficial to some, suggest researchers in the British Medical Journal. The researchers argue that the uptake of this procedure will have few social consequences and is likely to be a reasonable use of limited health resources. Since the 1980s, over 2,500 cycles of PGD have been performed worldwide. A common objection to using the procedure for the benefit of a sibling is that children conceived in this way are not valued in their own right. The authors argue that psychological harm to the offspring is unpredictable, unlikely to occur, and, even if it did occur, unlikely to be so severe that it would be better for that particular child never to have existed. Who is harmed by allowing PGD to be performed solely for the benefit of a relative, they ask? Not the couple who wish to produce an embryo. Nor the child who would not otherwise have existed. Nor the person who receives the stem cell transplant that might save his or her life.
NASA TO HELP FIRE-DAMAGED MONET PAINTING
A fire-damaged painting by Claude Monet could be restored to its former glory, thanks to a technology designed to simulate the ravages of low-Earth orbit on spacecraft, New Scientist reports. The painting, one in the French impressionist's celebrated Water-lilies series, suffered severe smoke damage in a blaze at New York's Museum of Modern Art in 1958. MOMA later gave the soot-covered artwork to the Center for Conservation at New York University's Institute of Fine Arts, where it has been used as a teaching tool. However, conservators at the institute are talking to space chemists at NASA's Glenn Research Center in Cleveland after hearing of their success in removing an overzealous art lover's lipstick from an Andy Warhol painting. Their trick? They vaporize contaminants by blasting them with oxygen. In low Earth orbit, solar radiation splits atmospheric oxygen molecules into highly reactive oxygen atoms that bombard spacecraft and damage their surfaces. NASA designed a small device that produces a short-lived beam of atomic oxygen and helium about three millimeters wide. "It's like an airbrush," Sharon Miller says. In tests on paint chips taken from a corner of the ruined Monet, the team found the atomic oxygen easily vaporized soot and dark particles of charred binder -- the component that gives paint its stickiness -- but did not react with the colored pigment.
SCIENTIST MONITORS PLANT SCREAMS
A German physics researcher is making plants scream, the Ananova Web site reports. University of Bonn scientist Ralph Gaebler uses a special sensor to register plant gas emissions. When under stress, plants give off increased amounts of ethylene gas. The sensor translates the gas concentration into noise. The German newspaper Express reports Gaebler demonstrated the method by cutting a leaf off an orchid, which caused a piercing scream. "The orchid cannot run away, so this is its way of complaining about such mean treatment," says Gaebler. The researcher caused the same effects by infecting a cucumber with mildew. Gaebler says his machine frequently registers "screams" coming from fruit baskets. "Apples naturally give off lots of ethylene gas," he says. "If there are any bananas in the basket, they will quickly turn brown from it."
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