Niacin, a B vitamin that raises "good" cholesterol, has failed to benefit heart disease patients when taken in tandem with a statin drug that lowers "bad" cholesterol, according to drug maker Merck.

On this edition of Valley Writers Read, author Jon Frank brings us a story about the adventures of mountain climbing in Yosemite Valley. 

Sandy Hook shooter Adam Lanza has been described as "quiet" and "different." Unconfirmed reports have suggested that he may have had autism or Asperger's syndrome. Host Michel Martin looks at the speculation about Lanza, and talks about the myths and truths about autism and Asperger's syndrome with two moms and a child psychiatrist.

The latest stories about how the nation is reacting to last Friday's school shooting in Newtown, Conn., which left 20 first-graders and six adults dead at Sandy Hook Elementary School, include:

Did you know the Affordable Care Act stands up for gun rights? The "Protection of Second Amendment Gun Rights" section says the health law's wellness programs can't require participants to give information about guns in the house. It also keeps the U.S. Department of Health and Human Services from collecting data on gun use and stops insurance companies from denying coverage or raising premiums on members because of gun use.

There was a 5.9 percent rise in sales of previously owned homes in November from October, the National Association of Realtors says.

At their 5.04 million annual rate, sales were the highest since November 2009.

"Momentum continues to build," NAR chief economist Lawrence Yun says in the organization's report.

The New York Stock Exchange will be acquired by IntercontinentalExchange of Atlanta in a deal valued at about $8.2 billion, the two rivals confirmed Thursday morning.

In matching press releases, they say the sale "combines two leading exchange groups to create a premier global exchange operator diversified across markets including agricultural and energy commodities, credit derivatives, equities and equity derivatives, foreign exchange and interest rates."