The white picket fence, the perfect house.

And then this thing here I'm hoping as you drive by you'll hear the picket fence effect of the sound hitting it.

The last strike at the end of April saw the postponement of nearly 13,000 routine operations and 100,000 appointments as nurses and consultants were drafted in to provide cover for doctors on the picket line.

Tom Sawyer pulled off that business strategy when he persuaded his friends to pay him for the privilege of taking over his hated chore, painting the picket fence. But most scientific research subjects either receive compensation or contribute their time free of charge they do not pay to participate.