nhk world's tack yeah kawasaki reports from okinawa. >> reporter: propellers slowly turning under the surface of the sea. it could be the first step to capturing the energy of the ocean currents. it's part of an ambitious project led by a professor and his team at okinawa institute of science and technology. the plachb is to create a network of 300 huge propellers positioned a hundred meters under the surface. they could generate 1 million kilowatts, equivalent to the power from a nuclear reactor. the researchers want to top the power of the current by flows northward past the islands and along the coast. this deep slow-moving current provides a constant flow of moving water making it's deal for generating power. >> translator: once the turbines have been placed deep down in the current, we'll have a constant source of daily energy. >> reporter: the first step for the team is to test a small prototype turbine. the turbine is suspended under the water from a buoy on the surface. to replicate the current the turbine is pulled through the water at a child's walking speed. the propellers

takaya kawasaki, nhk world, okinawa. >>> a large number of houses were damaged by liquefaction after last year's massive earthquake in northeastern japan. a research team held an experiment to test a new med method that makes houses more resistant. tokyo denki professor susumu yasuda and a major housing maker worked together on the development of the technology. under the new method, steel plates are placed around the foundation of a house. when liquefaction occurs after an earthquake, soil under the house loses strength and starts to sink. but when steel plates are used, the liquefied soil stay in place as it can't go anywhere else. therefore, the house remains upright. the experiment was conducted in scuba city northeast of tokyo. two model homes were built on a platform that could simulate earthquakes. the house on the left was reinforced by steel plates. both houses were built on saturated soil. they were shaken for one minute. about 20 seconds later, water began seeping from the ground. the house on the right began to tilt and eventually sank 20 centimeters. the house with the s

and more while breast-feeding. >> there were contributing factors, plus the kawasakis, that i believeely why he had autism. and why he had seizures. >> reporter: the 50-year-old mother of two other children, is now an advocate for an organic, chemical-free lifestyle, believing her heartbreak could have been avoided. preston said her family had started to make a change to an all-organic, chemical-free lifestyle before her son died. she said it was helping him, quote, that he was coming out of autism. although, many in the medical community do not believe there are known cures to the disease. >>> joining us, now, is senior abc contributor, dr. jennifer ashton. this is a controversial topic. but listening to kelly talk about this raises the question of, are children born with autism that develops as they get older? 2, 3, 4 years of age? or is it something they contract in their life? >> and this is an exciting time in autism research because every day, we're learning more and more. we think at this point that there are multiple factors at play. in the past, people had heard, it's a genet