Science news in brief, September 29, 2013

Termites' poop may be their secret to survival

Scientists trying to understand why wood-eating termites are so resistant to extermination have come up with a repugnant explanation. Termites' practice of building nests out from their faeces creates a scatological force field that Florida scientists now believe is the reason biological controls have failed to stop their pestilential march. A nine-year study concluded that termite faeces act as a natural antibiotic, growing good bacteria in the nests that attack otherwise deadly pathogens, according to findings published this month in the Proceedings of the Royal Society B. "Over the millions of years of evolution, termites somehow evolved to take advantage of their poop," said University of Florida's Nanyao Su, the study's lead scientist. Reuters

Fruit-picking robot gives farmers a break

A robot that picks ripe strawberries as the farmer sleeps was unveiled in Japan on Wednesday, with its developer saying it could cut workloads by two-thirds. The device, which can gather a fruit every eight seconds, uses cameras to determine which strawberries are ripe before snipping them into its basket. The two-metre robot moves on rails between rows of strawberries, usually grown in elevated planters in greenhouses in Japan. It "calculates the degree of ripeness from the colour of the strawberry, which it observes with two digital cameras", said Mitsutaka Kurita, an official of Shibuya Seiki, the company which developed the machine. AFP

Skyscraper firm ditches concrete for wood

The movement to construct tall buildings largely with wood as an environmentally friendlier alternative to steel and concrete has received a boost from an unusual source - a leading architectural firm known for its towers of steel and concrete. Chicago-based firm Skidmore, Owings & Merrill, which designed a long list of skyscrapers including the new One World Trade Centre in Manhattan, has developed a structural system that uses mass timber - columns and thick slabs laminated from smaller pieces of wood. The firm showed how the system could be used to build a 42-story residential tower with a lower carbon footprint than a conventional structure. "We wanted to see what we can do to help on the sustainability side," said firm partner William Baker. With their system, about 70 per cent of the structural material is wood; most of the rest is concrete. New York Times