Scientists have long assumed that female mammals -- women included -- were born with a finite number of eggs. That tenet of reproductive biology is increasingly in doubt. On July 29 researchers from Massachusetts General Hospital and Harvard Medical School published a paper in the journal Cell demonstrating that transplanted adult stem cells from either bone marrow or blood can cause egg cells to regenerate in mice.
The team placed the donor material from normal mice into infertile mice. Within a day the barren mice started generating new egg cells, and two months later their ovaries were identical to those of fertile mice. The researchers credit stem cells.
The finding may explain why some women who are unable to conceive regain fertility after receiving bone marrow or blood transfusions. And if the researchers can prove the new egg cells produce viable babies, their discovery might lead to new, stem-cell-based treatments for infertility.
If weather-forecasting computers around the world could compare notes as easily as people chitchat about the oppressive summer heat, meteorologists would have a much better way to forecast disasters such as hurricanes -- or coming Ice Ages. But the dozens of supercomputers that simulate the earth's climate were built at different universities and government agencies, each with custom code, so it's next to impossible to get them to talk to one another.
On July 20, NASA researchers announced that they're testing a software platform designed to solve those problems. The product allows researchers to switch components in and out of different simulations and to test and create more precise global models of the weather in a snap. Researchers believe the improved collaboration will not only aid short-term forecasting but also will boost their understanding of issues such as global warming.
Imagine a cheese slicer so precise that it could shave off a layer of cheddar no thicker than a single atom. That gives a sense of what scientists at Britain's University of Manchester have done to many materials, including graphite, using a process called micromechanical cleavage.
The resulting ultrathin sheets are stable at room temperature and extremely pure. They could be useful in everything from anti-rust coatings to single-molecule components for electronics. "This may well be a revolutionary discovery," says Vladimir I. Falko, a professor at nearby Lancaster University. So far, the Manchester team has created prototypes of a chemical sensor and one of the smallest and fastest transistors.
The next challenge will be to make the material easier to work with at sizes of about one-hundredth of a millimeter in diameter. Real-world uses may be a decade away.
Cat lovers have always known that their finicky friends don't like sweets. Now they know why. In July researchers from the Monell Chemical Senses Center in Philadelphia and the Waltham Center for Pet Nutrition in Leicestershire, Britain, discovered a genetic characteristic that prevents cats from tasting sugary ingredients.
The feline discovery could have implications for human health. In both cats and people, a pair of genes produce two proteins that allow us to recognize and respond to sweets. But in cats, part of a gene is missing, causing one of the protein spigots to turn off.
Studying the same system in people might reveal whether genetic mutations determine who will have a sweet tooth. That could help in the fight against obesity. For example, food makers may be able to chop calories by making trace amounts of sugar taste better.