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Researchers in the UK have built the world’s first sonic tractor beam that can lift and move objects using sound waves. The researchers used high-amplitude sound waves to generate an acoustic hologram which can pick up and move small objects. It might yield interesting applications such as a sonic production line to transport delicate objects without physical contact says one of the team, professor Bruce Drinkwater.

New research shows how eels use their self-generated electricity as a sophisticated remote control system. Ken Catania and his team at Vanderbilt University in the United States have used video and sound recordings to paint a detailed picture of the sequence and timing and of an eel’s attack. Catania especially focuses on the behaviour of the eel in curling its body to sandwich the prey.

Film is powerful and is something that a group of health advocates, doctors, patients and film-makers want to tap into more to spread public health messages. They believe that film is the ideal medium to communicate stories, to inspire and encourage people about their health; even address health inequalities round the world. They have organised the first Global Health Film Festival at the Royal Society of Medicine in London. Dr Joseph Fitchett is a clinical research fellow at Harvard School of Public Health and a co-founder of the Global Health Film Initiative, the partnership behind the festival.

When data revealed from the Rosetta spacecraft that oxygen was found on Comet 67P in 2014, it so surprised scientists that they carefully explored the findings and took a year before they were convinced it was true. Dr Andre Bieler describes why this is ‘the most surprising discovery about the comet so far’.

Earlier this year there was outrage when a dentist with a cross bow wounded a lion which then had to be humanely killed. But while many are convinced that trophy hunting should be banned there are others who argue that such hunting is actually necessary for conservation. The biologist, professor Adam Hart travels to Southern Africa to investigate the ethics of hunting in the light of cold economics.

Michael Kaloki reports from the streets of Nairobi on board a matatu bus trying out the Digital Matatus app. The app now benefits from a collaboration with Google Maps and aims to help commuters navigate the hundreds of matatu minibus routes.

(Photo: Holograms are three-dimensional light-fields that can be projected from a two-dimensional surface. Researchers have created acoustic holograms with shapes such as tweezers, twisters and cages that exert forces on particles to levitate and manipulate them. Image courtesy of Asier Marzo, Bruce Drinkwater and Sriram Subramanian © 2015)