Science briefs: Naps may aid preschoolers

Researchers tested 40 children in the morning by showing them a picture on a card, then flipping the card over and asking the child to remember its location on a grid.

The children then continued their regular program. At around 2 p.m., half the children were encouraged to nap, while the other half were given activities to keep them awake. The researchers retested the children after nap time, and again the next morning. All the children participated both as nappers and non-nappers.

When children napped, they scored higher on tests of recall afterward than when they stayed awake for the same time period. Nappers also did better on tests the next day. The findings were published online in The Proceedings of the National Academy of Sciences.

"Children not only need to nap, but should be encouraged to nap," said the senior author, Rebecca M.C. Spencer, an associate professor of psychology at the University of Massachusetts Amherst. "Schools are getting pressure to add curriculum and activities, but naps serve an academic function as well."

Scientists have discovered still another trick in the portfolio of brood parasites — the birds that deceitfully lay their eggs in the nests of other species, that way increasing their own numbers by duping other mothers into raising their young.

A new study reports that one parasitic species, the cuckoo finch, lays multiple eggs in the same nest, giving it a better chance of fooling a host mother. If she were confronted with just one finch egg, she might be able to identify it and throw it out. "The same female repeatedly lays multiple eggs in the host's nest and confuses the host," said an author of the study, Martin Stevens, an evolutionary biologist at the University of Exeter in England. "Once they hatch, the host seems to accept them as her own."

Along with colleagues from the University of Cambridge, Stevens went to sub-Saharan Africa to study the behavior of the cuckoo finch and one of its deceived hosts, the African tawny-flanked prinia. They reported their findings in the journal Nature Communications.

A research team has invented a method to reduce the time required for seedlings to bear apples to a year or less, down from the normal five to 12 years.

The new technique was developed by a group led by plant pathology expert Nobuyuki Yoshikawa, a professor at Iwate University's Agriculture Faculty.

The group says that the technique will also lead to significant reductions in apple cultivation time and that the method is expected to be applied to other fruits. The university has filed for a patent for the technique.

Yoshikawa and his team extracted a nonvirulent virus from apples, then planted two separate genes that accelerate and inhibit flowering into the virus. The team then implanted the virus in seedlings shortly after they sprouted.

Apple trees from those seedlings started to flower within 1½ months to three months, bearing fruit within 11 months after the virus transmission.