In this October 15, 2014 file photo, Katsu Nakamura, sky division manager for Yamaha USA, moves the RMax unmanned helicopter into position before a demonstration of its aerial application capabilities at the University of California, Davis' Oakville Station test vineyard in Oakville, Calif. Researchers at UC Davis have been studying the effectiveness of the drone's ability for spraying pest control and nutritional materials on the test vineyard in California's Napa Valley. (Photo by Rich Pedroncelli/AP Photo)

Kagome Co's employee Shigenori Suzuki tries to eat a tomato which is fed to him by the newly-developed “Wearable Tomato” device for runners, during its unveiling event ahead of the weekend's Tokyo Marathon in Tokyo February 19, 2015. The eight-kilo (17.6-pound) contraption fits on a runner like a rucksack. It can distribute a total of seven medium-sized tomatoes, one by one, at the click of a button and supplies the runner with much needed nutrients during a long jog or race. (Photo by Toru Hanai/Reuters)

Supporters of the presidential candidate Muhammadu Buhari and his All Progressive Congress hits with a motorbike another supporter during celebrations in Kano March 31, 2015. Nigeria's opposition APC declared an election victory on Tuesday for former military ruler Buhari and said Africa's most populous nation was witnessing history with its first democratic transfer of power. (Photo by Goran Tomasevic/Reuters)

Model Cara Delevingne is surrounded by photographers as she arrives to attend German designer Karl Lagerfeld's Spring/Summer 2016 women's ready-to-wear collection show for fashion house Chanel at the Grand Palais which is transformed into a Chanel airport during the Fashion Week in Paris, France, October 6, 2015. (Photo by Charles Platiau/Reuters)

Makoto Chino eats a purple haze carrot as he works harvesting the morning's vegetables and fruit from his family's farm in Rancho Santa Fe, California August 12, 2014. The gravitational pull of Chino Farm is legendary. Since they don't ship, everyone – whether a top chef or a traveling foodie or a local resident – comes to the farm stand, simply called “Vegetable Shop”, on a dusty corner of this affluent San Diego County town, hemmed in by sprawling housing estates. (Photo by Mike Blake/Reuters)

People leave a giant air purifier, which its inventor calls a “super tree”, in Lima's district of Jesus Maria November 24, 2014. In Peru's notoriously polluted capital Lima, local inventor Jorge Gutierrez, a retired naval engineer, is deploying the giant air purifiers that double as billboards to suck up carbon dioxide and dangerous levels of smog. (Photo by Mariana Bazo/Reuters)

A worker sweeps leaves below a historic spirit still at Suntory Holdings' Yamazaki Distillery in Shimamoto town, Osaka prefecture, near Kyoto, December 1, 2014. Nestled at the foot of wooded hills near the ancient Japanese capital of Kyoto, the Yamazaki whisky distillery feels a long way from the northerly glens of Scotch's spiritual home. Despite its unlikely birthplace, last month Yamazaki's Single Malt Sherry Cask 2013 trumped more than a thousand challengers to be named the world's best whisky by leading critic Jim Murray in his Whisky Bible 2015. (Photo by Thomas Peter/Reuters)

Models painted in camouflage colours to blend in with the background pose for Chinese artist Liu Bolin's artwork “Dongji”, or Winter Solstice, on the second day after China's capital Beijing issued its second ever “red alert” for air pollution, in Beijing, China, December 20, 2015. In this artwork, Liu wants to express his concerns about China and its people, including air pollution problem, Liu told Reuters. (Photo by Kim Kyung-Hoon/Reuters)