The technology builds upon the advances of , a technique that has been used to build box shapes, DNA scissors and other materials. Now, bioengineers have produced a single-stranded coil of protein that spontaneously sprang into a pyramid shape. While just an early demonstration, the technique could someday be used to make vehicles for drug delivery or to catalyze reactions.

"It is a piece of great work in the field of programmed biomacromolecular self-assembly," said chemist Chengde Mao of Purdue University in Indiana, who was not involved in the study. "The beauty of the strategy is its simplicity." []

are the molecular building blocks that carry out a host of vital functions in cells. They are composed of long chains known as polypeptides, which coil and fold to form complex 3D structures.

The idea with protein origami is to create rigid segments that can self-assemble in a modular fashion, like LEGO bricks. The segments are "smart" materials, because they contain all the information for the final structure inside them.

For the bricks, researchers designed well-studied structures called "coiled-coil segments" a combination of two or more helices that intertwine. They then made a chain of 12 of these segments stitched together on flexible hinges, which self-assembled into a pyramidlike shape known as a . Each edge of the tetrahedron was bounded by two of the segments.

"The shape is completely different from anything natural," said senior study author Roman Jerala, a synthetic biologist at the National Institute of Chemistry in Ljubljana, Slovenia.

Jerala and his colleagues confirmed the tetrahedron's formation using several kinds of microscopy. Each tetrahedron was only about 5 nanometers on an edge, about one ten-thousandth the width of a human hair.

Right now, it's just a proof of principle, Jerala told LiveScience. But ultimately, protein origami could be used to , for instance, to allow their controlled release. Or these structures could act as catalysts for reactions, much like enzymes in living cells.

Creating similar shapes using DNA origami is cheaper and easier to handle than proteins, said Paul Rothemund of Caltech, who was not involved in the study. But protein origami lets you make them much finer. "Making structures out of DNA is like building molecular structures out of DUPLO blocks [giant LEGOs]," Rothemund said, but "working with proteins, on the other hand, is sort of like working with adult LEGOs they have a much smaller intrinsic resolution."

Scientists have created small objects out of proteins before, but these had to be symmetrical shapes, Jerala said. Using protein origami, "we can take natural elements and do something completely different that does not exist in nature," Jerala said. "Nature just didnt explore all the possibilities."

The findings were detailed today (April 28) in the journal Nature Chemical Biology.

Follow Tanya Lewis on and .Follow us , & . Original article on.

The FDA has regulated tanning beds and sun lamps for over 30 years, but for the first time ever the agency says those devices should not be used by people under age 18. The agency wants that warning on pamphlets, catalogues and websites that promote indoor tanning. And regulators are also proposing that manufacturers meet certain safety and design requirements, including timers and limits on radiation emitted.

The government action is aimed at curbing cases of melanoma, the deadliest form of skin cancer, which have been on the rise for about 30 years. An estimated 2.3 million U.S. teenagers tan indoors each year, and melanoma is the second most common form of cancer among young adults, according to the American Academy of Dermatology.

Recent studies have shown that the risk of melanoma is 75 percent higher in people who have been exposed to ultraviolet radiation from indoor tanning. While most cases are diagnosed in people in their 40s and 50s, the disease is linked to sun exposure at a young age.

Physician groups have been urging the U.S. government to take action on tanning beds for years, citing increases in the number of cases of skin cancer among people in their teens and 20s.

"As a dermatologist I see the consequences of indoor tanning. I have to diagnose too many young people with melanoma and see the grief that it causes to these families," said Dr. Mary Maloney of the American Academy of Dermatology, on a call with FDA officials. Maloney said the FDA action is an important first step, but that her group would continue to push for a ban on the sale and use of tanning beds for people under age 18.

Earlier this year, a study of Missouri tanning salons found that 65 percent of 250 businesses surveyed would accept children ages 10 to 12, often without parental permission. The study was conducted by dermatologists at the Washington University School of Medicine in St. Louis.

Currently the machines are classified as low-risk devices, in the same group as bandages and tongue depressors. The proposal would increase their classification to moderate-risk, or class II, devices. That would allow the FDA to review their safety and design before manufacturers begin selling them.

"They don't have to provide any data in advance before they go on the market, so we have no way of providing assurance that the tanning beds are performing up to specifications," said Dr. Jeffrey Shuren, FDA's director for medical devices.

Safety standards are important because recent studies show that many devices can cause sunburn even when used as directed. A 2009 study found that 58 percent of adolescents who tan indoors had sunburn exposure.

"If you get an indoor tan you shouldn't be burning," Shuren said.

The Indoor Tanning Association said it supported any changes that improve its customers' safety. But, in a statement, the group added that "we are concerned that these changes will burden our members with addition unnecessary governmental costs in an already difficult economic climate."

The FDA proposal would not place warnings on the devices themselves, but on related promotional material and websites. Some consumer advocates said those warnings might never actually reach users.

"The FDA is requiring that the labels and pamphlets include risk information about skin cancer, but consumers would not be required to see those labels or pamphlets they are apparently only for the company buying the tanning bed," said Diana Zuckerman, of the National Research Center for Women and Families.

The agency said it will take comments on its proposal for 90 days before formulating a final regulation. Agency officials didn't give a timeframe for completion, but said it would be a priority.

It has since eased those worries.

On Wednesday the world's biggest social networking company said nearly a third of its advertising revenue came from mobile in the first three months of the year, helping to push total revenue up 38 percent to surpass Wall Street's expectations.

"They are making the transition to mobile faster than anyone anticipated," said Sterne Agee analyst Arvind Bhatia. "It seems like they are delivering."

Facebook Inc. said Wednesday that its net income was $219 million, or 9 cents per share, in the January-March period. That's up from $205 million, or 9 cents per share, in the same period a year ago, when it was still private.

Revenue grew to $1.46 billion from $1.06 billion, above analysts' expectations of $1.44 billion.

Excluding special items, mainly related to stock compensation expenses, Facebook earned 12 cents per share, matching the average of analyst expectations, according to FactSet.

Menlo Park, Calif.-based Facebook said that its mobile advertising revenue was 30 percent of its total ad revenue in the first quarter, amounting to $375 million. That's up from 23 percent, or $306 million, in the fourth quarter. In the third quarter the first time it disclosed such figures the company generated 14 percent, or $153 million, of its advertising revenue from mobile.

Investors had been worried about Facebook's ability to grow mobile revenue since before its initial public offering in May 2012. That's because although the number of people who access Facebook on smartphones and tablet computers has been growing quickly, Facebook didn't begin showing ads to those users until last year.

David Ebersman, Facebook's chief financial officer, said most advertisers did not specify that their ads be shown only on desktop computers or only on mobile devices, "rather they put their ads into our system and allow us to show the ads on whatever device where the ads will perform best."

Bhatia thinks Facebook will fare even better on mobile devices once Zuckerberg firms up its plan to make money from the growing audience checking into Instagram, a photo-sharing service that the company bought last year for $521 million. The analyst believes Instagram will play a bigger role in Facebook's business next year.

Wedbush analyst Michael Pachter said the results are likely to quiet skeptics who doubted Facebook's ability to mine its growing mobile traffic for revenue. He was particularly impressed by the 23 percent increase in Facebook's mobile ad revenue, even though the company's overall ad revenue for the period dipped 6 percent from the final three months of last year.

"Their mobile business is probably bigger than any mobile business on the planet other than the (wireless telecommunications) carriers and Google," Pachter said.

Facebook started showing mobile advertisements in early 2012. In the third quarter of last year, the company generated 14 percent, or $153 million of its advertising revenue from mobile. In the fourth quarter mobile ads represented to 23 percent, or $306 million.

Research firm eMarketer says Facebook's share of the U.S. online advertising market is growing. This year, the company is expected to take a 6.5 percent share of U.S. online ad spending, up from 5.9 percent in 2012. Still, that figure is far behind Google Inc.'s 41.6 percent.

On the mobile front, eMarketer expects Facebook to take a 13.2 percent share of U.S. ad revenue, up from 9.5 percent in 2012, the first year it made any money from mobile ads. Though Facebook is No. 2, it is far behind Google in U.S. mobile advertising. EMarketer expects the online search leader to take a 54.7 percent share of U.S. mobile advertising revenue this year.

The company also grew its user base during the quarter. This has also been an area of some concern to investors amid chatter of "Facebook fatigue," especially among younger users, surfacing in recent months. But Facebook said its monthly user base grew to 1.11 billion accounts as of the end of March, up 5 percent from 1.06 million at the end of December.

The number of users who access Facebook every day, on average, grew 8 percent to 665 million in March, from 618 million in December.

Gartner Inc. analyst Brian Blau said the ongoing growth of daily users suggests that the service is a tough habit to break.

"The network remains in full force," Blau said. "You have to give them a lot of credit."

That doesn't mean there won't be concerns about some Facebook users, especially teenagers, migrating to other mobile applications and digital outlets to hang out with friends and share slices of their lives, said Forrester Research analyst Nate Elliott.

"There is always going to be something new in social," Elliott said. "The question is how much of it is a threat to Facebook? All Facebook can do is keep those users coming back and make money off those users. And Facebook seems to be doing both of those things reasonably well."

Instagram now has 100 million monthly users, up from 22 million when Facebook agreed to buy the company in April 2012.

Facebook's stock rose 12 cents to $27.55 in after-hours trading. The stock closed down 34 cents on Wednesday. It is up 3 percent since the beginning of the year compared with an 11 percent increase for the Standard & Poor's 500 index. Facebook went public on May 18, 2012, at $38 per share, a price it hasn't hit since.

__

AP Technology Writer Michael Liedtke in San Francisco contributed to this story.

NEW YORK (TheWrap.com) - Ask a group of pro wrestling fans to name their favorite lord of the ring and you might get 10 different answers.

Older fans grew up idolizing Hulk Hogan, Andre the Giant and "Nature Boy" Ric Flair while newer fans might list Shawn Michaels, Stone Cold Steve Austin and John Cena.

Yet ask those same people to pick their favorite wrestler-turned-movie star and the decision gets a whole lot easier.

There's only one choice.

Dwayne Johnson, better known as The Rock, has starred in three movies over the past three months, "Snitch," "G.I Joe: Retaliation" and "Pain & Gain," and each film was the top new release at the box office its opening weekend.

His next movie, "Fast & Furious 6," will have to face down "The Hangover Part III" and "Epic" to keep that streak alive, but no one questions whether it will be a hit. Every film in the franchise has been, and early projections suggest the only question is whether it will hit $500 million, $750 million or $1 billion worldwide.

Johnson is currently in the midst of a streak unheard of not only in the history of former wrestlers but also other athletes who tried to cross over into the film business. Hogan, Cena, Shaq and even O.J. Simpson made a few movies, but none of them became a bona fide movie star. (Note: One sage reader pointed out that we forgot about Olympic swimming gold medalists Johnny Weissmuller and Buster Crabbe, who became "Tarzan" and "Flash Gordon," respectively. How could we forget Weissmuller's yell?)

"Everyone sitting in my chair is trying to work with Dwayne," Jeff Kirschenbaum, co-president of production at Universal, which has released five movies starring Johnson, told TheWrap. "I don't think he's having a moment. This isn't his 15 seconds of fame. He now has enough experience and craftsmanship that it's going to be a long run."

While this isn't the first time Johnson has been atop the box office, this is his first uninterrupted string of hits. His early films ranged from financially successful ("The Scorpion King," "The Game Plan," "The Tooth Fairy") to disappointing ("Doom," "The Rundown").

"I don't know that no one took him seriously because of wrestling, but he's the only person who has ever truly emerged out of that," an individual close to Johnson, who declined to be identified, told TheWrap.

So how did this happen? How did a former football player and member of the inimitable Rock 'n' Sock Connection became one of the most successful actors working today?

It starts with protein.

"He wakes up at 4 a.m. just so he can eat protein," Kirschenbaum, skinny as the Rock is broad, said. "He goes back to bed for an hour and at 5 a.m. he works out - when most people aren't even awake. He woke up an hour early just so the protein is already there to build muscle."

Johnson's morning routine has become a Hollywood legend, alongside Sean Penn's partying and Amanda Bynes' drunk driving.

Ask anyone who's worked with Johnson why he has succeeded where others have failed and they jump to tell a story about those pre-dawn workouts. It's what Ric Roman Waugh, who directed Johnson in "Snitch," dubbed the actor's "sweat equity."

"A lot of people can say 'we worked hard and can stay up late'," Waugh said. "But if they could only understand the amount of stuff he's putting into one day, it's astounding. The sky could be falling in his world, but in that moment you need him to focus, he's 100 percent with you."

That workload has only increased over the past two years. Since resurrecting his wrestling career in 2012, Johnson has expanded his film and TV work. Not only is he starring in several movies this year, but he just produced his first film, "Snitch," and is about to host a competition show on TNT, "The Hero."

When he first decided to try his hand at acting, Johnson retired from the WWE at the height of his popularity. Yet his specific wrestling personality explains why Johnson found his way in Hollywood where the likes of Hogan and Cena did not.

Like most any other wrestler, he can use his hands or a two-by-four to destroy someone. He demonstrated as much in early films like "The Scorpion King," where he played a mercenary, and "Walking Tall," where he played a veteran eager to rid his town of corruption.

Kirschenbaum described those early performances as "raw," and those early characters as two-dimensional. That is where the career path of most former pro wrestlers both started and stopped.

"Most wrestlers have been straight-forward characters or amped up versions of the real individual," Adi Shankar, producer of "The Grey" and an avid wrestling fan, told TheWrap. "Hulk Hogan acted in a bunch of B-movies playing Hulk Hogan."

Instead, Johnson and his representatives experimented from the get-go, taking roles most wrestlers would not want to touch.

He played the straight man next to Sean William Scott in "The Rundown," which also called for him to get dry humped by a gaggle of baboons.

He then played a gay bodyguard in "Be Cool," and later entered the family area with "Tooth Fairy" and "Journey 2." All of his hits in 2013 feature action scenes, but "Snitch" is an adult drama and "Pain & Gain" is as quirky as a Michael Bay movie comes.

"Most action stars out there would never ever break their brand," Waugh, a former stunt man, said. "They would read a script and see a scene where they get beat down and say the guy has to punch me at least 10 times and hit me with a bat 14 times. Dwayne is completely fearless."

Unlike most of his peers, Johnson's popularity in wrestling was never predicated on physical prowess or intimidation.

"Stone Cold would get over because he'd beat everyone up. Shawn Michaels was one of the greatest wrestlers of all time. Mick Foley would just do crazy stuff," Shankar said. "The Rock got over because he was funny. You take humor out of the Rock and you don't have anything."

Shankar can remember when he first fell in love with The Rock. The Undertaker, one of the largest, most intimidating wrestlers in the WWE, had just battered and bruised the former football player. At the next event, The Rock came out and challenged him.

"He said 'Undertaker, you think you impress The Rock with your Mickey Mouse tattoos?' He acted like the Undertaker's goal in life was to come out and impress The Rock," Shankar recalled. "He wasn't a heavyweight champion at this point - just a guy coming up. The Undertaker had been around for a decade."

He was a showman first and a wrestler second.

"No matter how bad the show was, The Rock could cut a promo and save it," Shankhar said. "He could get on the mic and speak for three minutes and save a bad show."

Some claim the same now applies to poorly received films, with some dubbing Johnson franchise Viagra. Did your last sequel fail? Hire Johnson.

Some, like Waugh, love this term. Yet many chafe against the idea that Johnson saved their movies, believing it disrespectful to the previous success of the franchises he joined.

Whether Viagra or a supporting hand, there is one thing all directors and studio executives can agree on.

"My biggest concern on my next movie is that he's not in it,"Waugh said.

I have a history of alcoholism and she's a hoarder. A week ago, I had an "epiphany": I am desperately trying to quit drinking for my own sake.

Abby, I am a clean freak living with a hoarder. I come home from work and get depressed and stressed from looking at all the clutter. It is driving me insane. I feel like it is triggering me to stay drunk every night.

I don't want to lose this woman and her family, but I can't co-exist in this house. I have left several times, only to miss her and go back. I'm trying to kick the booze, but I know I won't be able to achieve sobriety while living in this house. -- TRULY TORN IN TEXAS

DEAR TRULY TORN: If you quit drinking only a week ago, it is important that you find an AA group to help you hang onto your sobriety. That's step one.

Next, realize that you and the lady you're living with may share a similar problem. You say you are a "clean freak." This can be a symptom of an obsessive-compulsive disorder. Hoarding can be a symptom of the same disorder.

The International OCD Foundation is a reliable resource that may be able to help you both. It offers individuals with this disorder the support they need to manage their symptoms, and has many local chapters. You can locate it online at www.ocfoundation.org or reach it by calling 617-973-5801.

DEAR ABBY: Maybe you would like to pass this on to the parents of teenage boys. It worked for me when I had the sex talk with my sons. I knew their brains had not yet fully developed. They thought they were invincible and had an "it could never happen to me" attitude.

Because money seems to be the one thing at that age they can relate to, I decided to turn it into a mathematical problem: I told them that if they got a girl pregnant, they could figure on a minimum of $300 a month child support, multiplied by 12 months for 18 years. (That totals $65,000 -- unless the girl has twins, which would double the amount.)

Then I told them if they were tempted to have unprotected sex, they should look at the girl and ask themselves if they would pay her $65,000 to have sex with them. If they couldn't answer yes, then they needed to walk away.

Abby, it worked! No grandchildren appeared until after they were married. Feel free to share this with other parents who would appreciate a "non-traditional" approach that is effective. -- TONY IN SAN DIEGO

DEAR TONY: Gladly. I'm passing your technique along because money is a great motivator, and your idea makes "cents."

DEAR ABBY: My roommate insists that undershirts should be washed right-side-out. I say as long as you're using detergent and bleach, it doesn't matter. Who is right? -- MR. CLEAN IN OCEANSIDE, CALIF.

DEAR MR. CLEAN: I don't claim to be a domestic goddess, but I don't think there is a right or wrong way to wash undershirts. I have heard, however, that washing garments inside out will prevent lint buildup on the outside, and in the case of denim, less fading.

Dear Abby is written by Abigail Van Buren, also known as Jeanne Phillips, and was founded by her mother, Pauline Phillips. Write Dear Abby ator P.O. Box 69440, Los Angeles, CA 90069.

Good advice for everyone -- teens to seniors -- is in "The Anger in All of Us and How to Deal With It." To order, send your name and mailing address, plus check or money order for $7 (U.S. funds) to: Dear Abby, Anger Booklet, P.O. Box 447, Mount Morris, IL 61054-0447. (Shipping and handling are included in the price.)

* NBA Commissioner praises Collins for breaking barrier

* White House commends him for his courage (Recasts with quotes and background)

By Julian Linden

NEW YORK, April 29 (Reuters) - Veteran basketball player Jason Collins announced on Monday that he was gay, smashing through one of the final frontiers in U.S. sports with a frank personal statement and winning warm praise as a groundbreaker.

Collins, a 12-year player in the National Basketball Association (NBA), became the first active athlete from any of the four major U.S. men's professional sports leagues to come out publicly as gay.

He was quickly enveloped in a wave of support from the White House to tennis player Martina Navratilova, a pioneer for gay athletes in sport.

Collins is not a well-known sports star but is now likely to become famous for his stance. He revealed the secret he had harbored for years in a first-person account published in Sports Illustrated, saying he had gradually become frustrated with having to keep silent on his sexuality.

"I'm a 34-year-old NBA center," his essay began. "I'm black. And I'm gay."

Collins said he had considered coming out years ago but it was the Boston Marathon bombings this month that convinced him not to wait any more for a perfect moment to come out.

"I wish I wasn't the kid in the classroom raising his hand and saying, 'I'm different.' said Collins, who played last season with the Boston Celtics and then the Washington Wizards and is currently a free agent. "If I had my way, someone else would have already done this. Nobody has, which is why I'm raising my hand."

Players, administrators and some politicians applauded him for taking a stance. Some hailed it as a landmark day in American civil rights, perhaps as important as when Jackie Robinson broke the color barrier in baseball.

President Barack Obama, a big fan of the NBA who regularly plays pickup basketball with his friends, supported Collins' decision.

"I can certainly tell you that here at the White House we view that as another example of the progress that has been made and the evolution that has been taking place in this country, and commend him for his courage, and support him in his - in this effort and hope that his fans and his team support him going forward," said White House spokesman Jay Carney.

DEBATE OVER GAY RIGHTS

Collins' move came at a time of shifting attitudes toward gay rights in the United States, where polls show public opinion is fast moving toward greater acceptance, although a core ofsocial conservatives oppose such change.

In the coming months, the Supreme Court will rule on whether to strike down parts of a federal law that defines marriage as the union between a man and a woman. In 2011, the military repealed a ban on openly gay soldiers.

"Jason's announcement today is an important moment for professional sports and in the history of the LGBT (lesbian, gay, bisexual, transgender) community," former U.S. president Bill Clinton said in a statement.

NBA commissioner David Stern said he was proud of Collins for taking a brave stance.

"Jason has been a widely respected player and teammate throughout his career and we are proud he has assumed the leadership mantle on this very important issue," Stern said.

In a country where it is no longer news for politicians and entertainers to be openly gay, there had been questions over the lack of an openly gay player in the big four men's professional leagues: the National Basketball Association, the National Football League, the National Hockey League and Major League Baseball.

Sports, which helped play a key role in changing public opinion on racial discrimination, had come to seem out of step with much of the rest of American society.

Collins, who has played with six different teams during his 12 years in the NBA, said he never had any grand plans to bethe first openly gay player, but events off the basketball court persuaded him to come out.

He was inspired by last year's gay pride parade in Boston, he said, but delayed making an announcement due to a desire to protect his team, waiting until the end of the regular 2012-2013 season ended. Collins was also prompted by the April 15 Boston Marathon bombings which killed three people and wounded more than 200, he said.

"The recent Boston Marathon bombing reinforced the notion that I shouldn't wait for the circumstances of my coming out to be perfect," he wrote in Sports Illustrated. "Things can change in an instant, so why not live truthfully?

PRAISE FLOODS IN

Kobe Bryant, one of the NBA's greatest players, was fined $100,000 in 2011 for a homophobic slur. On Monday, he was among the first of dozens of active players who took to social media to applaud Collins.

"Proud of @jasoncollins34. Don't suffocate who u r because of the ignorance of others," Bryant tweeted.

Two-time NBA Most Valuable Player Steve Nash tweeted: "The time has come. Maximum respect."

There are openly gay players in many top professional leagues in other countries in the world as well as smaller leagues in North America and individual sports.

Navratilova, the tennis star who also became a champion for gay rights, said Collins would feel like a burden had been lifted from him.

"Hey Jason Collins-you are now an activist!!! And trust me, you will sleep a lot better now - freedom is a sweet feeling indeed!," she tweeted.

Other gay athletes, including former NBA center John Amaechi, had waited until their retirement to divulge their sexuality publicly, but there was a growing sense that times were changing.

Earlier this year, the American soccer player Robbie Rogers outed himself, although he had just retired. And Brittney Griner, one of the country's top women's basketball players, said she too was gay.

But there were still no currently playing, openly gay athletes from the four biggest men's leagues.

The question came into sharp focus this year around theNational Football League (NFL), usually viewed as the most macho of America's pro sports.

In the days leading up to this year's Super Bowl in New Orleans in February, San Francisco 49ers cornerback Chris Culliver told reporters he would not welcome a gay teammate into the locker room.

He later retracted his comments but reports later emerged of NFL teams asking college players about their sexuality at a scouting session in February.

This prompted the New York State attorney general to send a letter to the NFL, urging the league to take action and adopt a formal policy on discrimination over sexual orientation.

High-profile NFL players, most notably Chris Kluwe and Brendon Ayanbadejo, began advocating for gay rights, and suggested there were a handful of players ready to come out once someone had taken the first step.

"All of us have huge admiration for what Jason is doing," said Patrick Burke, co-founder of equal rights advocacy group You Can Play.

"Jason's courage in stepping forward with his personal story will provide athletes and fans with a new role model." (Editing by Frances Kerry and Tim Dobbyn)

Chinese scientists compared swabs from birds at markets in eastern China to virus samples from four patients who caught the new H7N9 virus. The scientists found the virus from one patient was nearly identical to one found in a chicken. The research was published online Thursday in the journal Lancet.

Finding definitive proof of how patients were infected is very difficult and experts have so far struggled to find much virus in birds. Despite taking nearly 48,000 samples from animals in live markets, Chinese officials found only 39 positive tests for H7N9. Experts had suspected birds in live markets to be the source of infection but weren't sure if other animals or wild birds might also be responsible.

Health officials have so far refrained from recommending any wide-scale slaughter of poultry to contain the disease, one of the main tools used previously to combat another bird flu strain, H5N1. Unlike that strain, H7N9 doesn't appear to sicken chickens, giving experts fewer signs as to where it might be spreading.

Chinese authorities have shut down live poultry markets in many affected regions, which seems to have slowed down the virus. Still, Taiwan reported its first case earlier this week.

So far, H7N9 has infected more than 100 people in China and killed more than 20.

NEW YORK (Reuters) - Stocks dipped in thin volume on Friday, though the market had a strong week overall despite a mixed bag of earnings and weak economic figures.

Shares of online retailer Amazon.com Incposted the largest daily drop in 15 months after the company reported results late on Thursday. It was Friday's biggest drag on the S&P 500 and Nasdaq indexes.

Gains in shares of Chevron Corpbuoyed the blue-chip Dow industrials.

The market fell early after a negative surprise from the gross domestic product report, but the decline attracted bargain-hunting investors late in the session. Major indexes posted solid gains for the week.

J.C. Penney Cowas the S&P 500's biggest percentage gainer, up 11.5 percent to $17 after CNBC reported Goldman Sachs lined up a $1.75 billion loan for the retailer. The news added to previous gains a day after investor George Soros reported a 7.9 percent passive stake in the company.

"We traded off a decent amount after the GDP number but we didn't break any technical levels or really didn't get much momentum in the selloff past late morning," said Paul Zemsky, head of asset allocation at ING Investment Management in New York.

"I guess there was some bottom fishing. There was so much fear of poor earnings going into earnings season that this is still somewhat of a positive surprise."

The Dow Jones industrial averagerose 11.75 points or 0.08 percent, to 14,712.55, the S&P 500lost 2.92 points or 0.18 percent, to 1,582.24 and the Nasdaq Compositedropped 10.72 points or 0.33 percent, to 3,279.26.

For the week, the Dow gained 1.1 percent, the S&P added 1.7 percent and the Nasdaq rose 2.3 percent.

Of the 271 companies in the S&P 500 that have reported earnings to date for the first quarter, 69 percent have beaten analyst expectations - above the 63 percent average since 1994 and slightly over the 67 percent beat rate over the past four quarters.

Eastman Chemicaldropped 5.1 percent to $68.97 a day after posting results, to lead percentage declines among S&P materials , which was the worst performing sector of the index with a 1.4 percent drop.

The S&P traded Thursday within a point of its historic closing high set earlier this month and the 1,593 level is expected to be technical resistance in the near future.

Gross domestic product expanded at a 2.5 percent rate in the first quarter, below estimates of 3 percent, heightening fears the U.S. economy could struggle to cope with deep government spending cuts and higher taxes that kicked in earlier this year.

Amazon.com shed 7.2 percent to $254.81 after it said revenue growth slowed in the first quarter as the company struggled overseas, but margins jumped on lower shipping expenses.

Chevron rose 1.3 percent to $120.04 after it posted earnings that beat expectations, even as lower oil prices bit into the profits of the second largest U.S. oil company.

The PHLX housing sector indexgained 1 percent, getting a lift from D.R. Horton Incafter the No. 1 U.S. homebuilder reported earnings. D.R. Horton shares closed at their highest in six years after an 8.7 percent jump to $26.60.

About 5.7 billion shares changed hands on the New York Stock Exchange, the Nasdaq and NYSE MKT, below the daily average so far this year of about 6.4 billion shares.

On the NYSE, roughly seven issues fell for every five that rose and on Nasdaq about three fell for every two advancing issues.

(Reporting by Rodrigo Campos; Editing by Kenneth Barry)

"If there is no basis to the , then how do you explain the suns alignment with the center of our galaxy that is predicted to occur on Dec. 21?"

Putting as earnest a look on my face as possible, I replied, "Youre absolutely correct the sun will indeed be aligned with the center of our galaxy on Dec. 21." I then quickly added, "But of course that happens every year on Dec. 21." []

The look on my inquisitors face was priceless. "Really? But how can that be?"

The sun's annual path

As the Earth moves around the sun, we see the sun change its position against the background stars a full 360-degree circle around the sky during the course of a year. That apparent path is known to astronomers asout toward the sky.

As it turns out, the moon and the seven other planets that comprise thealso move in orbits whose planes dont vary too greatly from that of Earths orbit. As a result, the moon and the other planets also appear to stay relatively close to the ecliptic.

The sun never deviates from the ecliptic and so as Earth travels around it, from our perspective, it will always take the exact same path against the same background stars every year.

Since when were looking towardwere also looking toward the center of the Milky Way, when the sun reaches that same point on the ecliptic in Sagittarius on Dec. 21 every year, the sun and the galaxys center are indeed aligned.

The ecliptic is a very important feature because it marks "the pathway," so to speak, for the sun, moon and planets as they move across the sky. Most sky charts plot the position of the ecliptic for this reason, for it provides sky watchers with a clue as to where one or more of these objects will appear.

Because theyre not located exactly in the same orbital plane as Earth, the moon and planets usually are not found exactly on the ecliptic line, but rather within several degrees of it. Thus, instead of a line, we find the moon and planets wandering along the sky within a band that encompasses the entire sky, which we call the zodiac.

The ecliptic runs exactly along the middle of that zodiacal band.

The 'classic 12'

The word "zodiac" is derived from the Greek, meaning "animal circle." A sort of "celestial zoo."

And with the sole exception of one of the "classic 12"that belong to the zodiac, all of the zodiac members refer to living things. Many of these constellations are named for animals, such as Leo, the Lion, Taurus, the Bull and Cancer, the Crab, just to name a few.

The sole inanimate member is Libra, the Scales.

All of these names can be readily identified on sky charts and are familiar to millions of horoscope users (who ironically would be hard pressed to find them in the actual sky.) []

If we could see the stars in the daytime, we would see the sun slowly wander from one constellation of the zodiac to the next, making one complete circle around the sky in one year.

Ancient astrologers were able to figure out where the sun was on the zodiac by noting the last zodiacal constellation to rise ahead of the sun, or the first to set after it. Obviously, the sun had to be somewhere in between.

Each month a specific constellation was conferred the title, "house of the sun," and in this manner each month-long period of the year was given its "sign of the zodiac."

Some discrepancies

A couple of years ago, a board member of the Minnesota Planetarium Society caused quite a stir when he pointed out that the zodiacal sign that had been assigned for a given month in the newspaper horoscope is not where the sun actually is for that month.

He pointed out that, in reality, todays astrologers continue to adhere toby at least a millennium. For instance, according to astrology, youre a Leo if you were born between July 23 and Aug. 22 because thats the time of year where the sun supposedly is in the zodiac.

That might have been true 1,000 years ago, but no longer. In fact, on July 23, the sun is not in Leo, but in Cancer. This discrepancy is due to the "wobble" of the Earths axis (known as precession).

As a consequence, there then came the revelation (even though it has been known by astronomers for a long time) that astrologers continue to adhere to star positions that for all intents and purposes are out of date by 10 centuries or more.

Outcasts of the zodiac

One thing that I have never been able to understand is why astrologers fail to recognize Ophiuchus, the serpent holder. He certainly should be considered as a card-carrying member of the zodiacal fraternity since the sun spends more time traversing through Ophiuchus than .

It officially resides in Scorpius for less than a week: from Nov. 23 to 29. It then moves into Ophiuchus on Nov. 30 and remains within its boundaries for more than two weeks until Dec. 17. And yet, the serpent holder is not considered a member of the Zodiac.

In addition, because theand planets are often positioned either just to the north or south of the ecliptic, they sometimes appear within the boundaries of several other non-zodiacal star patterns.

The revered Belgian astronomical calculator Jean Meeus has pointed out that there are actually 22 zodiacal constellations in which the moon and some of the planets from Mercury to Neptune can occasionally enter.

In addition to the 12 classical zodiacal signs and , we can also add: Auriga, the charioteer; Cetus, the whale; Corvus, the crow; Crater, the cup; Hydra, the water snake; Orion, the hunter; Pegasus, the flying horse; Scutum, the shield; and Sextans, the sextant.

And in case youre interested, in the upcoming month, the moon will be in Orion on May 13, Sextans on May 19 and Ophiuchus on May 26.

I guess you can say that so far as the celestial zoo is concerned, these three constellations are on the outside of the cage looking in.

Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for the New York Times and other publications, and he is also an on-camera meteorologist for News 12 Westchester, New York. Follow us on , and . Original article on .