Twitter Inc, the social network known for its 140-character messages, hinted at the direction of its evolution on Thursday with the launch of a new streaming video service for smartphones.
The service, called Vine, records six-second-long video clips, which can then be seamlessly embedded within tweets.
The foray into video marks the beginning of a new thread in Twitter's development, which evolved from a simple SMS text-messaging service in its early days into a platform that now delivers multimedia content.
Privately held Twitter, which was founded in 2006 and is now expected by analysts to go public within two years, has spent the past year encouraging marketers to use its multimedia capabilities to deliver ads.
"Like Tweets, the brevity of videos on Vine (six seconds or less) inspires creativity," Michael Sippey, a Twitter vice president, said on the company's blog.
Twitter's increasing emphasis on delivering video through its network has stirred speculation that it could eventually host longer content and grow into a bona fide media broadcaster.
The network has supported embedded YouTube videos since 2009, but for the first time, Twitter itself will host video content with Vine.
Thursday's roll-out was the product of Twitter's 2012 acquisition of Vine, then a three-person startup based in New York. Twitter has spent recent months integrating Vine's video technology into its service, as well as launching Vine as an independent app for Apple's iPhone.
US researchers tracking flu through Twitter
Researchers and computer scientists at Johns Hopkins University have devised a way to track cases of influenza across the United States using the microblogging site Twitter.
Twitter is full of tweets about the flu, which has been severe and reached epidemic proportions this year, but it has been difficult to separate tweets about the flu from actual cases.
"We wanted to separate hype about the flu from messages from people who truly become ill," said Mark Dredze, an assistant research professor in Johns Hopkins' department of computer science, who monitors public health trends by looking at tweets.
To solve the problem, Dredze and his colleagues developed a screening method based on human language-processing technologies that only delivers real-time information on actual flu cases and filters out the rest of the chatter on the public tweets in the United States.
The researchers at the Baltimore university tested the system by comparing their results with data from the U.S. Centers for Disease Control and Prevention.
"In late December," Dredze said on Thursday, "the news media picked up on the flu epidemic, causing a somewhat spurious rise in the rate produced by our Twitter system. But our new algorithm handles this effect much better than other systems, ignoring the spurious spike in tweets."
The scientists, whose research was funded partly by the National Institutes of Health's Models of Infectious Disease Agent Study, have also produced maps of the United States that show the impact of the flu on each state.
Dredze said he hoped the system could be used to track the other illnesses.