Young urban investors are teaming up with farmers in Nigeria to help them scale up production.
A $1m prize has been awarded for a gadget that triggers an alert if a woman is attacked.
Strangers are sharing unwanted food in a bid to save money and reduce food waste.
Smart, digital bins are being used to cut food waste and save money in commercial kitchens.
A van has been converted into a laundrette to wash homeless people's clothes in Athens.
A growing movement in the UK is shifting the power of catching speeding motorists from the police to the people.
How one school is bridging the gap between divided communities in Israel.
How one man is getting ordinary Palestinians and Israelis to talk peace with each other.
How one community works together to stop people feeling isolated