Earlier parental-mandated bedtimes could help protect teens from depression and suicidal thoughts by lengthening sleep duration, according to new research.

Scientists have found a direct relationship between carbon dioxide emissions and global warming. Researchers used a combination of global climate models and historical climate data to show that there is a simple linear relationship between total cumulative emissions and global temperature change.

Four suspects often found at the scene of the crime in cancer are guilty of the initiation and progression of breast cancer in mice that are resistant to the disease, a team led by scientists have found.

It's conventional wisdom in atmospheric science circles: Large raindrops fall faster than smaller drops because they're bigger and heavier. And no raindrop can fall faster than its "terminal speed." Now a team of physicists has determined that it ain't necessarily so.

As stroma -- the supportive framework of the prostate gland -- react to prostate cancer, changes in the expression of genes occur that induce the formation of new structures such as blood vessels, nerves and parts of nerves, said researchers.

Scientists have developed a new type of fish-shaped, bionic robot as an alternative means of marine propulsion that might replace ships’ screws in sensitive waters.

[The following is an exact transcript of this podcast.]

What do a hummingbird, a moth, and a maple tree have in common? They all use a similar trick to fly. Okay, okay, a maple tree doesn’t fly. But its seeds kind of do. Maples make those little whirlybird seeds you see spiraling down in droves each spring. Their papery little wings keep them aloft so they can find a good place to germinate and make a new maple. But how they manage to fall so slowly has been a bit of a mystery--until now. [More]

Although the H1N1 virus has not proven as deadly as the annual bouts of seasonal flu, the World Health Organization (WHO) raised the pandemic threat level today from 5 to 6, the highest designation, signaling that there has been substantial "community transmission" on multiple continents.  [More]

Dear EarthTalk: How does the microwave compare in energy use, say, to using a gas or electric stove burner to heat water for a cup of tea? -- Tempie, Dexter, MI

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Students who consider themselves to be evening types (that is someone who feels more alert and does their best work later in the day) have poorer sleep hygiene scores than morning and intermediate types.