RIO DE JANEIRO (AP) — The Latest on the 2016 Summer Olympics in Rio de Janeiro (all times local):

3:10 p.m.

The International Olympic Committee is taking extra security measures at the Olympic doping lab in Rio de Janeiro to prevent a repeat of the brazen manipulation of samples at the 2014 Winter Games in Sochi.

IOC medical director Dr. Richard Budgett says "we can be very confident" that the thousands of doping samples at the Rio lab are secure.

Extra security was put into place following the scandal over state-sponsored doping in Russia, where tainted samples were swapped out for clean ones during clandestine, middle-of-the-night operations at the Sochi lab.

Budgett says there is a "huge" presence of security officers at the Rio lab, as well as an extensive network of surveillance cameras throughout the facility.

Budgett says he will personally review footage from the cameras, including those trained on the freezers where the samples are stored.

___

2:45 p.m.

MEDAL ALERT: Eleftherios Petrounias of Greece has won the Olympic gold medal in men's still rings.

The reigning world champion put together a precise routine, finishing with a stuck dismount to post a score of 16.000. Arthur Zanetti of Brazil captured silver, delighting the home crowd inside Rio Olympic Arena. The crowd repeatedly shushed itself during Zanetti's set then exploded when his score of 15.766 flashed.

Denis Abliazin of Russia earned bronze

___

2:45 p.m.

A leading Russian independent newspaper has issued a passionate appeal to lift a ban on Russian athletes competing at the Rio Paralympics.

The Novaya Gazeta, known for its biting criticism of the Kremlin and its exposure of official corruption, said in Monday's letter that the ban "will hit absolutely innocent athletes, their relatives and friends, and everyone who see hope in the Paralympic Movement."

Russia was banned from the games by the International Paralympic Committee last month. The Russian Paralympic Committee filed a formal appeal Monday, and the hearing at the Court of Arbitration for Sport is expected to issue its verdict next Monday.

___

2:30 p.m.

Russian whistleblower Yulia Stepanova says she fears for her safety since hackers infiltrated both her email account and the anti-doping system that keeps track of her whereabouts.

Stepanova, the 800-meter runner who was denied a spot in the Olympics by the International Olympic Committee, says she, her husband and their young son recently moved to another undisclosed location in the United States.

Stepanova unveiled details that led to the discovery of a wide-ranging doping system inside her home country. The Russian track team has been banned from the Olympics, but the IOC has allowed 278 athletes in other sports to compete.

Stepanova said she would of course like to be in Rio De Janeiro, but she has heard stories about crime and lack of security in the Olympic city and thinks it would be easy for someone to hurt her if she were in Brazil right now.

The World Anti-Doping Agency said last week that hackers had accessed their system. Included in that was information about Stepanova's whereabouts. All athletes are required to provide that information so they can be reached in case they're chosen for an out-of-competition drug test.

___

2:20 p.m.

Germany has defeated the United States 2-1 in the women's field hockey quarterfinals.

Germany's Marie Mavers opened the scoring Monday with a goal midway through the first period. Lisa Altenburg knocked in a backhanded shot high over USA goalie Jackie Briggs to put Germany up 2-0 late in the first.

The Americans came up empty on a penalty corner with two minutes left in the third period. Katelyn Falgowski's goal with 3:54 remaining gave the Americans a chance, but the Germans held on.

The United States failed to medal after a strong start. The Americans beat No. 2 Argentina and No. 3 Australia in their first two matches at the Games, then beat Japan and India to take the lead in their pool.

The United States led their final pool play match against Britain heading into the fourth period before losing 2-1.

___

2:05 p.m.

MEDAL ALERT: Charlotte Dujardin and Valegro have clinched a second successive gold dressage medal, setting an Olympic record in the process.

To the sound of samba music, the British rider posted a score of 93.857 percent and beat the record she set in London four years ago, also on Valegro.

Dujardin was the only rider to surpass the 90 mark on Monday. She finished ahead of Isabell Werth and Kristina Broring-Sprehe, who were both part of the Germany team that won Friday.

It was a fourth silver medal for Werth and a 10th overall.

Werth had a score of 89.071 on Weihegold OLD, with Broring-Sprehe posting 87.142 on Desperados.

___

2 p.m.

Japanese tire manufacturer Bridgestone has become the first commercial sponsor of the new Olympic Channel.

The International Olympic Committee says Bridgestone signed a four-year deal to become a "founding partner" of the digital channel, which will launch after the opening ceremony of the Rio Games on Sunday night.

Terms of the deal, which lasts through 2020, were not announced.

The channel, which will operate 24 hours a day, 365 days a year, is designed to promote Olympic sports and ideals between the games.

The IOC says Bridgestone will initially sponsor the channel's "Against All Odds" series, an eight-episode documentary that follows eight athletes.

Bridgestone has been one of the IOC's official worldwide sponsors since 2014.

___

1:30 p.m.

Russia is atop the standings after the duet technical routine in synchronized swimming.

Natalia Ishchenko and Svetlana Romashina scored 96.4577 points for their routine Monday. They also led after the free routine a day earlier, giving them a combined score of 194.5244.

Huang Xuechen and Sun Wenyan of China were second at 191.4355. Yukiko Inui and Risako Mitsui of Japan were third at 187.5214.

Americans Anita Alvarez and Mariya Koroleva was ninth. The duet free final is Tuesday.

___

1:20 p.m.

New Zealand's Lisa Carrington, the world's top female kayaker, made paddling look easy as she made the final of the 200-meter sprint.

The four-time world champion and defending Olympic titleholder cruised through two heats in first place to win a spot in the Tuesday final. She looked relaxed, which pleased her coach Gordon Walker.

Carrington, 27, is also competing in the 500-meter sprint.

In the men's 1,000-meter canoe singles, defending Olympic champion Sebastian Brendel is through to the final along with home crowd favorite Isaquias Queiroz of Brazil and Serghei Tarnovschi of Moldova. All three won their heats Monday.

Danuta Kozak and Gabriella Szabo paddled into the final of the women's 500-meter kayak doubles while Australia's Murray Stewart is set to race for medals in the men's 1,000-meter kayak singles after clocking the fastest time in the semifinals.

___

1:20 p.m.

Through the first half of the Olympics, women have seen more screen time on NBC in the evening — particularly in beach volleyball.

A study issued Monday found women athletes were featured in 58.5 percent of the competitions show on NBC's prime-time. That's the highest percentage since three college professors began keeping track in 1994. London 2012 was the first Olympics competition where the U.S. broadcaster showed women more often than men.

Much of the advantage was because of a disparity in beach volleyball coverage, where most women wear bikinis. Through Saturday, NBC showed two hours, 45 minutes of women's beach volleyball, and 35 seconds of men.

There's been criticism of the media, including NBC, for commentary perceived as sexist during the Olympics. The most-cited case was NBC crediting the husband of a Hungarian gold medal swimmer for his wife's success.

___

12:50 p.m.

Nicholas Bett, who won a surprising world title in the 400-meter hurdles last year, has been disqualified in the first round at the Olympics.

The 26-year-old Kenyan was contending for the lead in heat 5 when he crashed into the 10th and last hurdle. He stumbled and crossed the finish in last spot, and was later disqualified. Michael Tinsley, the Olympic silver medalist in 2012, also failed to qualify after placing fifth in the last heat.

Two other Americans reached the semifinals, with Byron Robinson clocking 48.98 seconds and two-time world champion Kerron Clement running 49.17.

Annsert Whyte of Jamaica led qualifying in a personal best 48.37 and London Olympic bronze medalist Javier Culson of Puerto Rico ran 48.53.

___

12:50 p.m.

Brazilian native Miriam Nagl has been chosen to hit the opening tee shot in women's golf on Wednesday.

Nagl was born in the southern state of Curitiba. She says it was overwhelming to hear that she would hit the first shot for women's golf in the Olympics since 1900 in France.

Adilson da Silva of Brazil hit the first tee shot for the men last week.

Nagl lived in Brazil for 10 years and now lives outside Berlin. She will be playing alongside Leona Maguire of Ireland and Kelly Tan of Malaysia.

Maguire is among three amateurs who qualified for the women's competition.

___

12:50 p.m.

The biggest rivalry in Greco-Roman wrestling will resume Monday night in the heavyweight finals at the Rio Olympics

Cuba's Mijain Lopez, the two-time defending Olympic champion, will face Turkey's Riza Kayaalp for the gold.

Kayaalp has twice bested Lopez, beating the Cuban for the world title in 2011 and 2015. But Lopez didn't allow a point in reaching the finals.

The 85-kilogram final will feature top-ranked Ukrainian Zhan Beleniuk against Russian Davit Chakvetadze.

Beleniuk is the defending world champion, but Chakvetadze beat him in the finals of a recent Grand Prix in Azerbaijan.

As for the Americans, they'll leave Rio without a medal after Ben Provisor and Robby Smith lost first-round matches and failed to qualify for the repechage rounds.

The U.S. didn't qualify in the weights to be contested Tuesday, the final day of Greco competition.

It's the second straight medal-less Olympics for the American team, but few expected the U.S. to excel in Greco. Andy Bisek was the only one on the team ranked in the top 10 in the world, and he went 1-1 on Sunday.

___

12:50 p.m.

Muhammad Ali has lost in the Rio Olympics boxing ring. The 20-year-old British flyweight carrying the enormous burden of his famous name lost every round on every card in his debut bout Monday, dropping a decision to Venezuela's Yoel Finol.

Ali is a top amateur boxer, but he never got comfortable in Rio despite a Brazilian crowd chanting his name.

A teary-eyed Ali says he "just tried too hard, and nothing was working. It's going to be heartbreaking to see them on the podium and not me."

___

12:30 p.m.

The rowers are gone and so is the wind.

The canoe sprint competition has started on the Rodrigo de Freitas Lagoon without the blustery conditions that dominated the rowing regatta last week.

With only a soft breeze in the air, canoeists and kayakers faced no waves except for the wakes left by competitors in front of them.

"I think it's much calmer today," Swedish paddler Linnea Stensils said after qualifying for the final of the women's 200-meter sprint. "I didn't feel any waves at all."

The rowing competition lost two days due to gusty weather. The canoe sprint competitors race on a shorter course that's less exposed to the winds.

___

12:15 p.m.

Another American man is out of the Olympic boxing tournament with a solid performance and a lesson for the future.

Antonio Vargas lost on his 20th birthday Monday, dropping a unanimous decision to Uzbekistan's Shakhoibidin Zoirov.

Vargas accepted the decision with grace, even after putting on a strong third round against his older opponent. The prospect from Kissimmee, Florida, felt he could have changed things in a fight lasting longer than three rounds.

Vargas says he's learned a lot of things at the Olympics and "they're going to make me a better boxer going forward."

The six U.S. men in Rio dropped to 9-4 at the Olympics with one bronze medal and two boxers still scheduled to fight for medals this week. That's a marked improvement on the nine-man London team, which won only five fights and failed to bring home a medal.

The Americans' two women boxers in Rio are also still alive. Lightweight Mikaela Mayer fights for a medal later Monday, and middleweight Claressa Shields finally begins her gold-medal defense Wednesday.

___

12:05 p.m.

Russia will find out early next week whether it can compete at the Rio Paralympics after filing an appeal against its ban with the Court of Arbitration for Sport.

Russia was banned from the games by the International Paralympic Committee last month when IPC president Philip Craven said evidence of mass doping cover-ups in Russia showed a "medals over morals" mentality incompatible with the games.

The Russian Paralympic Committee said it filed a formal appeal Monday and expected the hearing at CAS to take place Sunday with a decision by midnight Aug. 22.

Russian athletes have a mixed record at CAS, which last month upheld a ban on its Olympic track and field team, but earlier Monday allowed a single Russian athlete, Darya Klishina, to compete in Olympic track on appeal.

___

12:05 p.m.

Anita Wlodarczyk of Poland recorded the two best marks in history to win the Olympic women's hammer throw final, improving the world record to 82.29 meters.

The 31-year-old world champion dominated the final after throwing an Olympic record 80.40 on her second attempt, twice throwing beyond her previous world-record mark of 81.08.

Wlodarczyk's third attempt was her best and locked up the gold, and she followed up with 81.74 with her fifth.

Zhang Wenxiu of China won the silver medal with her season-best 76.75 and Sophie Hitchon of Britain moved into the bronze medal position with her last attempt of 74.54.

___

11:50 a.m.

MEDAL ALERT: Anita Wlodarczyk of Poland has won the Olympic women's hammer throw gold medal with a world record of 82.29 meters.

Zhang Wenxiu of China took silver with her season-best 76.75 and Sophie Hitchon of Britain moved into the bronze medal position with her last attempt of 74.54.

___

11:50 a.m.

Ruth Jebet opened a huge gap halfway through and didn't look back to win gold in the women's 3,000-meter steeplechase in the second fastest time ever.

A world record was on the cards at the Olympic Stadium on Monday until the final few meters when Jebet slowed. She crossed in 8 minutes 59.75 seconds, less than a second off the world mark of Russia's Gulnara Galkina.

The Kenya-born Jebet, who represents Bahrain, now holds two of the three fastest times ever over the barriers.

Kenya's Hyvin Kiyeng Jepkemoi, the world champion, claimed the silver medal but was over seven seconds behind Jebet.

American Emma Coburn, who led in the early stages, took bronze to be the first woman from the U.S. to win an Olympic medal in the steeplechase.

___

11:45 a.m.

The spokesman for the Rio Games organizing committee has apologized to U.S. swimmer Ryan Lochte and three of his teammates over how they were robbed earlier this week, and revealed that security officials have been asked to be even more vigilant going forward.

Through the U.S. Olympic Committee, Lochte said he and fellow U.S. swimmers Gunnar Bentz, Jack Conger, Jimmy Feigen were robbed when the taxi they were in early Sunday was stopped by people posing as police officers. Lochte told NBC that one of the robbers held a gun to his forehead.

"We obviously regret that the violence has (gotten) so close to athletes," Rio Games spokesman Mario Andrada said Monday. "We have requested security authorities that they need to make sure everybody's safe everywhere in the city. We apologize to those involved. Once again, we regret that violence is still an issue at these games."

Street crime was a major concern of Olympic organizers going into the games, and there have been several high-profile problems on that front since the games started.

___

AP Summer Games website: http://summergames.ap.org