 One unmanned ground vehicle can be built in four days in a shed for about $35,000, or roughly 10% of the cost of an imported model. In all, about 250 defense startups across Ukraine are now creating the drones from the bottom up. If you're worried about mental sharpness, keep an eye on your credit. Credit scores can be an early warning sign of cognitive decline, says a study from the New York Federal Reserve and Georgetown University.