Serena Williams' 17-match winning streak at the Australian Open ended Monday in a stunning 6-2, 6-3 loss to Ekaterina Makarova, the lowest-ranked woman in the fourth round.

The dominant force at Melbourne Park this century, Williams had lost only two matches at Melbourne Park since winning the first of her five Australian Open titles in 2003. After losing in the 2008 quarterfinals, she won titles in 2009 and 2010 before sitting out last year because of injury.

British adventurer Felicity Aston has crossed Antarctica, becoming the first woman to cross the icy continent alone.

Aston also set another record: the first human to ski across Antarctica using only her own muscle power.

One of the world's most endangered turtles has been released into a Cambodian river with a satellite transmitter attached to its shell to track how it will navigate through commercial fishing grounds and other man-made hazards.

The 75-pound (34-kilogram) southern river terrapin — one of only about 200 adults remaining in the wild — waddled into the Sre Ambel river in southwestern Cambodia this past week to the cheers of local residents and conservationists.

Tablets and e-readers were a popular gift over the holidays, so much so that the number of people who own them nearly doubled between mid-December and January, a new study finds.

A report from the Pew Internet and American Life Project set to be released Monday found that 29 percent of Americans owned at least one tablet or e-reader as of the beginning of this month. That's up from 18 percent who said the same in December.

Kei Nishikori keeps accumulating the tennis milestones for Japanese men, always remaining conscious of but not concerned about the expectations being heaped upon him.

Nishikori notched another mark Monday when he became the first Japanese man to reach the quarterfinals of the Australian Open since the Open Era began in 1968 with an exhausting 2-6, 6-2, 6-1, 3-6, 6-3 victory over former finalist Jo-Wilfried Tsonga of France.

A quarter-century after the U.S. Food and Drug Administration approved the first prescription drugs based on the main psychoactive ingredient in marijuana, additional medicines derived from or inspired by the cannabis plant itself could soon be making their way to pharmacy shelves, according to drug companies, small biotech firms and university scientists.

A British company, GW Pharma, is in advanced clinical trials for the world's first pharmaceutical developed from raw marijuana instead of synthetic equivalents— a mouth spray it hopes to market in the U.S. as a treatment for cancer pain. And it hopes to see FDA approval by the end of 2013.

What would Steven Tyler, the American Idol judge, think of Steven Tyler, who sang the national anthem at the AFC championship game on Sunday?

Let's just say the rendition probably wouldn't get him to Hollywood.

Sigourney Weaver may not believe in ghosts, but the paranormal world of her latest film is not alien territory for her.

Weaver's Sundance Film Festival premiere, "Red Lights," is a dark exploration of the supernatural realm she previously took on in comic mode with "Ghostbusters" and its sequel.

Oil fell to near $98 a barrel Monday in Asia as the crude market waited for the outcome of Greece's negotiations with creditors on a deal to cut the face value of its debt by half.

Benchmark crude for March delivery was down 15 cents at $98.19 a barrel at late afternoon Bangkok time in electronic trading on the New York Mercantile Exchange. The contract fell $2.21 to end at $98.33 per barrel in New York on Friday.

A trial over how music royalties of the late country singer "Gentleman" Jim Reeves should be split is set to begin this week.

Reeves was a country music sensation when he died nearly 50 years ago in a plane crash at the age of 39.