But last month,a computer programmer from Australia made an exciting discovery of an unusual event in Earth's solar system.

VOA: special.2009.08.25

But she says there is much evidence that nicotine in tobacco smoke affects the nervous system, and child development and behavior.

VOA: special.2009.01.13

An object in the solar system could be identified if it appeared to move from its place in the earlier photograph.

VOA: special.2010.07.11

He says they might be trying to increase their dopamine levels to make up for the deficits in their reward system.

VOA: special.2009.09.16

He says they might be attempting to increase their dopamine levels to make up for the deficits in their reward system.

VOA: special.2009.09.29

President Obama has signed legislation to make the biggest changes in the health care system in forty-five years.

VOA: special.2010.03.24

Professor Gaechter says social order in general can be explained as a system in which individuals behave cooperatively and follow social rules.

VOA: special.2009.03.03

But he hopes to raise billions through a system in which businesses that release greenhouse gases would buy and trade pollution permits.

VOA: special.2009.02.27

And now Ms.Rhee appears in the film "Waiting for 'Superman,'" a documentary about problems in the educational system.

VOA: special.2010.10.21

But he said the nation must not forget the near-collapse of the banking system in two thousand eight without fixing its causes.

VOA: special.2010.04.16

But Congress has put more into the budget of the national park system in the past three years.

VOA: special.2009.09.28

One showed that adults are much more cooperative if they work in a system based on rewards.

VOA: special.2009.10.21

For example, the Great Barrier Reef in Australia is the largest coral reef system in the world.

VOA: special.2009.04.22

The Northwestern University researcher took part in a study that found a way to turn off the immune system in mice with arthritis.

VOA: special.2010.03.16