LOS ANGELES (TheWrap.com) - BBC Middle East editor Jeremy Bowen, who was shot in the head while reporting on protests in Cairo on July 5, made it successfully through surgery to remove the shotgun pellets.

On July 11, Bowen tweeted that the operation was done, the pellets were removed and thanked all for their concern. He told a follower that he planned to spend the rest of the day watching cricket and recovering.

That's a bit different from how he spent his time immediately after being shot: After a quick break to have his wounds bandaged, he went back to work, getting his report together in time for that night's newscast. He then returned to England for medical treatment, bemoaning the fact that a visit to his surgeon prevented him from doing more reporting.

Bowen also tweeted that he was "slightly disappointed" that the shotgun pellets still embedded in his head didn't set off any airport metal detectors.

Mexico, who were stunned by Panama in the group opener but got their bid for a third consecutive Gold Cup title back on track by winning their remaining games, went ahead in the first half through Marco Fabian and Luis Montes before Kevin Parsemain's penalty made it 2-1.

Martinique had opportunities to equalize in the second half but could not make the breakthrough, and Miguel Ponce scored from close range in the 90th minute to make the game safe for the Mexicans.

In the earlier Group A match, Panama settled for a 0-0 draw with Canada to top the group on seven points.

(Writing by Jahmal Corner in Los Angeles; Editing by Peter Rutherford)

On July 1, the job cuts reached founding CEO, Mark Pincus, who will be replaced by former Microsoft Xbox chief Don Mattrick. (Pincus will stay on as chief products officer.) The change was enough to boost Zynga's stock a bit, but on Thursday the company is giving investorsto get excited about: Gambling. With . On Facebook.

At a World Gaming Executive Summit in Barcelona, Facebook's Sean Ryan is showcasing two new Zynga games, ZyngaPlusPoker and ZyngaPlusCasino, according to . Zynga "says that social gaming remains its heart and soul," , "but the gambling games are a logical extension for fans who want to bet real money and win it in social games."

The first step is conquering Britain, where online gambling is legal and regulated. In April, Zynga released online and downloadable versions of its two real-money games in the U.K., in partnership with established British poker company Bwin.Party Digital Entertainment. Facebook and mobile versions are coming soon.

Americans (and Britons) canon Facebook, where you pay real money for virtual chips that you can never cash out. The new versions, when they drop, will let people win (and lose, of course) real cash. Investors applauded the news because, well, gambling generates a whole lot of money. The Facebook component is key to Zynga's strategy.

Zynga and its investors believe, with some justification, that "the real-money Facebook games could be a game changer, luring in the general U.K. population that has known Zynga for years as a social gaming pioneer," . People who have been playing FarmVille and Mafia Wars may not be big on online gambling, but Zynga could change that, with Facebook's imprimatur.

Britain is "the ideal test-case for Zynga, with it's concentration of seasoned online gamblers contributing to a £2.3 billion ($3.4 billion) industry for the country," . But the company's "sights are no doubt set on the United States, which, despite its currently restrictive gambling laws, could be worth $9.3 billion by 2020."

Rep. Peter King (R-N.Y.) is pushing for legislation to drop all federal regulation of online gambling, leaving it up to individual states to decide what to allow. Nevada and New Jersey — home to Las Vegas and Atlantic City, respectively — have recently legalized the practice. (Nevadans canonline real-money poker against other Nevadans, and New Jersey and Delaware are setting up their online gambling systems.)

It won't be a slam dunk getting a chunk of the Jersey or Nevada markets — Zynga needs to partner with a casino in Atlantic City, and only two of the 10 are still up for grabs, says VentureBeat's Jeffrey Grubb. But as signs point toward more online gambling in the U.S., Zynga has put itself in a prime position to profit. It has an established brand plus loads of customer data to work with, and Facebook is a great platform for minting new online gamblers.

"It's too early to say whether Zynga's online gambling bet will pay off," . "But at least it's given investors a glimmer of hope."

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LOS ANGELES (TheWrap.com) - As "Argo" director Ben Affleck preps his next movie "Live By Night" for Warners, the actor has begun negotiating to play the male lead in David Fincher's "Gone Girl," people familiar with the project told TheWrap.

Reese Witherspoon is producing but will not star; an individual familiar with the project tells TheWrap that Oscar winners Natalie Portman and Charlize Theron are being eyed for the title role along with Emily Blunt.

Affleck's likely involvement in the 20th Century Fox project - based on the bestselling novel by Gillian Flynn - is expected to cement "Gone Girl" as Fincher's next movie.

Affleck would play a man implicated in the disappearance of his wife on the day of their fifth wedding anniversary.

Witherspoon is producing with her Pacific Standard partner Bruna Papandrea and Leslie Dixon. New Regency is co-financing "Gone Girl," which could start production as soon as this fall.

WME-repped Affleck next stars opposite Justin Timberlake in Fox's "Runner Runner," which hits theaters September 27.

The three research reports cover:

"There is exciting work going on in Alzheimer's research throughout the world, and the Alzheimer's Association is proud to be a leader in research and support some of the most promising avenues of investigation globally and here in Boston," said Maria Carrillo, Ph.D., Alzheimer's Association vice president of medical and scientific Relations. "These Boston-based research projects will enable us to learn about the course and progression of Alzheimer's, how to create effective drugs for the disease and how to catch it early enough that we can eventually prevent it.

"Yet our efforts alone and those of the scientists we fund cannot make the progress needed for the millions who have Alzheimer's now and the millions more who will get the disease unless we make bold steps now to wipe it out. Step one: the National Alzheimer's Plan must be fully implemented $100 million more is needed in the federal commitment to Alzheimer's and dementia research this fiscal year," Carrillo concluded.

One therapeutic approach being tested for Alzheimer's disease is to reduce the production of the beta amyloid protein and its accumulation into amyloid plaques by changing the action of two brain enzymes beta-secretase and gamma-secretase that create beta-amyloid from the amyloid precursor protein. Production and accumulation of beta-amyloid in the brain is thought to initiate a cascade of events leading to Alzheimer's disease dementia.

However, changing the function of these enzymes, with minimal side effects, resulting in improved cognition has proven to be a mighty challenge, as shown in the recent Phase 2 failure of Avagacestat (Bristol-Myers Squibb), a drug that inhibited the action of gamma secretase.

Corinne E. Augelli-Szafran, Ph.D., is director of the Laboratory for Experimental Alzheimer Drugs (LEAD) at Harvard Medical School and Brigham and Women's Hospital, Boston, an academic-based medicinal chemistry and drug discovery laboratory. LEAD was founded in 2006 by Drs. Dennis Selkoe and Michael Wolfe and is unique to the medical school and hospital environment. LEAD's efforts are devoted to the discovery of new Alzheimer's disease therapeutics.

"The main mission of our laboratory is to identify new drugs, called gamma-secretase inhibitors, that block the ability of the brain enzyme called gamma-secretase to produce beta-amyloid protein," Augelli-Szafran said. "However, gamma-secretase also has a normal function in the body. Therefore, it is essential that any potential drug only blocks beta-amyloid production while leaving the normal function of gamma-secretase intact."

At AAIC 2013, Augelli-Szafran reported that her laboratory has successfully identified several new compounds with these attributes. Based on studies in animals, these gamma-secretase inhibitors also possess other important advantages such as smaller size, better solubility, improved brain entry and a greater ability to reduce beta-amyloid production while leaving the normal function of gamma-secretase intact over similar drugs that had been tested in clinical trials and failed, according to the researchers.

Augelli-Szafran says some of the recent LEAD compounds demonstrate up to seven times the ability of Avagacestat at leaving the normal function of the enzyme intact. She says this attribute could translate to fewer side effects and less toxicity for these new compounds, but this still needs to be proven through further studies.

"Basic drug development work and animal studies are essential to fill the 'front end' of the drug development pipeline for Alzheimer's," Carrillo said. "With the Alzheimer's epidemic upon us, and the continued aging of the population, we need more treatment ideas developed and additional targets identified and the most promising therapies tested rigorously."

Alzheimer's disease is characterized by progressive decline in cognitive functioning, especially in memory but also executive functioning (including planning, attention and problem solving) and global cognition. Each person may experience Alzheimer's differently, and there are considerable differences in rates of decline between affected individuals.

"If we can understand more about the genetic basis of this variability in rate of decline, it could help illuminate the biological pathways involved in disease progression," said Richard Sherva, Ph.D., research assistant professor in the department of Biomedical Genetics at Boston University School of Medicine. "It also could inform the development of therapies to slow the progression of disease."

Sherva and colleagues are utilizing research funds awarded by the Alzheimer's Association to study the genetics of the rate of Alzheimer's-related cognitive decline in a large population from a completed clinical trial. By expanding their work into a multi-institutional consortium (known as Genetic Architecture of Rate of Alzheimer's Decline, or GENAROAD, led by Drs. Robert Green and Paul Crane), they have amassed a relatively large sample of Alzheimer's cases with the longitudinal data necessary to study the topic in depth.

At AAIC 2013, Sherva reported genome wide association studies (GWAS) from participants in multiple research studies including the Alzheimer's Disease Neuroimaging Initiative (n=301), National Alzheimer's Coordinating Centers (n=865), Religious Orders Study/Rush Memory and Aging Project (n=323), and AddNeuroMed study (n=123). The combined GWAS identified at least four genetic variants strongly associated with rate of decline in Alzheimer's, including SPON1, MANB4A, KCNJ14, MAP3K1 and HIBADH.

"We found that the genes that influence rate of decline are largely different that those that influence Alzheimer's risk in general but are genes involved in pathways related to Alzheimer's risk," Sherva said. "The most interesting gene we identified is called SPON1, which has functions related to beta-amyloid generation and also regulates brain cell connectivity."

Multiple recent unsuccessful late-stage drug trials in people with mild to moderate Alzheimer's disease have lead some in the field to believe that treating people when dementia symptoms are apparent is too late in the disease process and that we must move detection and intervention earlier in order to be effective. Some experts believe that the best time to treat individuals with Alzheimer's is when cognitive performance is still normal but there is evidence of Alzheimer's changes in the brain. This is described as preclinical (or presymptomatic) Alzheimer's in new diagnostic criteria published by the U.S. National Institute on Aging and the Alzheimer's Association.

One example of testing this strategy this is the Anti-Amyloid treatment in Asymptomatic Alzheimer's Disease (A4) trial, where researchers from the Center for Alzheimer Research and Treatment at Brigham and Women's Hospital, Boston, will test an amyloid-clearing drug in older individuals thought to be in the pre-symptomatic stage of Alzheimer's disease. The trial will enroll 1,000 older individuals with PET scan evidence of amyloid in their brains a hallmark of Alzheimer's but who do not show clinical symptoms of the disease. A key challenge is how to measure and track their cognitive status throughout the trial.

Dorene M. Rentz, Psy.D., associate professor of Neurology at Harvard Medical School and a neuropsychologist in the Departments of Neurology at Massachusetts General Hospital and Brigham and Women's Hospital, Boston, and colleagues tested whether performance on tests of memory and thinking in cognitively normal individuals was related to preclinical Alzheimer's disease.

The group studied 129 normal older adults, age 65 to 85, with cognitive tests and two PET brain scans: one that measures how the brain uses glucose (FDG metabolism) and another scan that measures the amount of brain amyloid plaques (PiB deposition).

The researchers found that people in the study with worse memory performance had higher PiB deposition and lower FDG metabolism in regions of the brain that are commonly affected in Alzheimer's. In contrast, individuals who performed worse on non-memory thinking tests had lower FDG metabolism but a normal PiB scan.

They also found that more highly educated individuals in the study performed normally on tests of memory despite lower FDG metabolism and higher PiB retention. "This may mean that education has a protective effect on cognitive performance in the early stages of preclinical Alzheimer's," Rentz said.

"Overall, our findings suggest that poor memory performance with both FDG metabolism and higher PiB deposition may help identify people who are at high risk for progression to Alzheimer's disease dementia," Rentz said.

About AAIC The Alzheimer's Association International Conference (AAIC) is the world's largest conference of its kind, bringing together researchers from around the world to report and discuss groundbreaking research and information on the cause, diagnosis, treatment and prevention of Alzheimer's disease and related disorders. As a part of the Alzheimer's Association's research program, AAIC serves as a catalyst for generating new knowledge about dementia and fostering a vital, collegial research community.

About the Alzheimer's Association The Alzheimer's Association is the world's leading voluntary health organization in Alzheimer care, support and research. Our mission is to eliminate Alzheimer's disease through the advancement of research; to provide and enhance care and support for all affected; and to reduce the risk of dementia through the promotion of brain health. Our vision is a world without Alzheimer's. Visitor call 800.272.3900.

SOURCE Alzheimer's Association

Its not just an apple a day that keeps the doctor away anymore recently, fish oils found in species like salmon, trout and tuna have been associated with a and even . In fact, the most recent revisions to the Dietary Guidelines for Americans in 2010 recommended consumers substitute high-fat protein sources with more seafood, including fatty fish.

Not surprisingly, fishhas since skyrocketed to be the most popularin the United States. A new study in the Journal of the National Cancer Institute,however, shows that these fish fats may not be improving everyones health in the trial, those with high concentrations of marine-derived omega-3s in their blood showed a 43% higher risk of developing prostate cancer than those with the lowest levels.

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Prostate cancer is the most common cancer in men, and while the latest statistics show that most men will eventually develop prostate cancer if they live long enough, only a specific type of cancer, known as high-grade, carries high risk of serious health problems. While a quarter of a million Americans are diagnosed with prostate cancer each year, only about 30,000 of those cases are fatal, and almost all of them involve high-grade cancer. The latest research found that the association between omega-3s and prostate cancer held for both high- and low-grade prostate cancers.

Its not that omega-3s are harmful, but that the fatty acids may have more complex effects on the body than previously thought. We have this tendency to talk about good foods and bad foods, good nutrients and bad nutrients, Dr. Theodore Brasky, a research assistant professor at The Ohio State University Comprehensive Cancer Center and the studys head author. The nutrients commonly found in fish fight potentially damaging inflammation, but they may also increase oxidative damage to the DNA in cells, similar to the effects of stress, that can create fertile ground for cancers to grow.

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The study measured omega-3 blood levels in the participating men, and did not include information on the volunteers eating habits, so researchers could not differentiate between the effects of fatty acids from fish from those of supplements. However, the overwhelming majority of the participants did not take fish oil supplements. Based on the results, Brasky says that men with a family history of prostate cancer should discuss with their doctor whether fish oil supplements are safe for them, since these pills tend to contain concentrated doses of omega-3 supplements contain between 30% to 60% of a serving of fish, and if a fish oil supplement is taken everyday, that adds up to a lot of daily fish oil. Brasky also suggested that men cut down on their fatty fish intake, though not eliminate it entirely.

Andrew Vickers, a statistician specializing in prostate cancer at Memorial Sloan-Kettering Cancer Center, agrees, saying that fish oil supplements may pose a relatively higher risk for prostate cancer than fish in the diet. The problem comes when you take components of a diet and put it in a pill, Vickers says.While the omega-3 fatty acids may increase oxidative damage to prostate cells, for example, anti-oxidants, which might be part of an overall healthy diet that includes fish as well as fruits and vegetables, might counteract these effects. Because the study did not query the men about their diets, its difficult to tell whether the men were consuming other healthy foods as well.

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Most health experts recommend that people try to eat a healthy, balanced diet to protect against diseases and most cancers, and turn to supplements only if thats not possible, since supplements may provide only partial benefits. Thats why the American Cancer Society does not currently recommend that men take fish oil supplements, according to Marjorie McCullough, the societys strategic director of nutritional epidemiology.

Braskys work isnt the first to suggest that omega-3 fatty acids may have both positive and negative effects on the body. In a September 2012in the Journal of the American Medical Association, researchers found that omega-3 supplements were not associated with lower risks of stroke or cardiac death. Those results were confirmed by another study in the New England Journal of Medicine that showed omega-3 supplements did not reduce risk of dying from a heart event among a group of people at high risk of . Researchers involved in those studies, however, acknowledged that they were not able to account for the effect of other medications to treat heart problems, such as cholesterol-lowering drugs and blood pressure medications, in keeping death rates down. In the same way, more research will have to tease apart how other nutrients in a balanced diet including antioxidants work together to influence the effect of individual nutrients like omega-3 fatty acids.

For one glimmering moment late last month, the Iranian capital was the talk of the world's art market after 80 works sold for $2 million, astonishing a country whose economy is battered by Western sanctions but still has pockets of wealth looking for investment havens for their money.

This is the other side to Tehran hidden by walls surrounding elite enclaves or in high-rise towers with doormen that has more in common with well-heeled spots in Manhattan or London.

Many in the gilded set of Tehran come from old merchant families. Others made it big in newer ventures: the export trade with the Gulf or the city's still-hot real estate market, where prime residential property prices in the overcrowded capital can reach Tokyo-level rates of $10,000 per square meter, or $929 per square foot.

Signs of wealth still appear in Tehran even as sanctions bite deeper over the country's nuclear program.

Car dealers get orders even at inflated price tags because of import complications for a $300,000 Mercedes Benz or BMWs at $200,000 each. Ice cream flaked with edible gold dust was a signature dish at the rotating restaurant atop Tehran's 435-meter (1,427-foot) Milad Tower. Officials chagrined by the extravagance banned the dessert in 2011, as tightening sanctions have led to shortages of medicine and protests over the soaring price of chicken.

Iran's stumbling economy has become such a political issue that it dominated debates before June's presidential election. The winner, Hasan Rouhani, has pledged to try to reverse painful inflation now running at about 30 percent and work to ease sanctions.

The art auction Tehran's second such event in the past year offered a rare window into the investment strategies of the city's rich, whose route to acquire assets overseas has been complicated by sanctions that bumped Iran from main international banking networks. Now some of Iran's wealth increasingly appears drawn to the rising profile and prices of Iranian art in galleries from Dubai to Los Angeles. In April, the painting "The Secret Garden" by Iranian artist Farhad Moshiri brought the highest price at a Christie's auction in Dubai at $987,750.

"They have learned that artworks have business and investment aspects while also having a high cultural and social prestige," said Saeed Leilaz, a prominent economic analyst in Tehran.

Iran's ruling clerics who once even banned music in the years after the 1979 Islamic Revolution now encourage Iran's vast artistic community that includes such luminaries as Oscar-winning director Asghar Farhadi. But there are limits. Strict bans are in place on anything that hints too strongly of political dissent or criticism of the theocracy.

Other artists have faced prosecution for alleged support of opposition movements. This month Iranian director Jafar Panahi appeared via Skype at the Karlovy Vary Film Festival in the Czech Republic after the screening of his film, "Closed Curtain," which he made in defiance of censors while under house arrest. Authorities imposed a 20-year filmmaking ban on Panahi in 2010 after his conviction on charges of "making propaganda" against Iran's ruling system.

The works on the auction block at Tehran's high-end Azadi Hotel the former Hyatt near the infamous Evin Prison played it safe, however. The collection, such as the 1970 painting "The Body of Trees," avoided any political overtones.

That piece, by the late painter and poet Sohrab Sepeheri, brought the highest price of the auction, about $220,000. The buyer, the private Pasargad Bank, already has bought more than 140 artworks in recent years as part of plans for a museum.

A photo entitled "Weeping Cow," by the internationally renowned film director Abbas Kiarostami, fetched $22,000 when the gavel came down. It was wielded by celebrity auctioneer Reza Kianian, a veteran film and television actor who has won the Iranian equivalent of an Academy Award.

"I did not expect that all works could be sold," Kianian said. "The excitement was very high, and that pushed me to raise the offers."

A photo by Jamshid Bayrami on the hajj, or Islamic pilgrimage to Saudi Arabia, was sold for about $6,000. Bayrami's works have been sold previously at Sotheby's auctions in London and Qatar.

"Many know that investment cannot be limited to real estate, gold and carpets," the photographer said. "It also shows the strength of Iranian art lovers and artists."

The manager of the auction, Ali Reza Samei Azar, said he had hoped to top last year's auction that brought in $1.3 million, but the sinking economy initially made him think they "were dreaming."

"We rarely see the sale of 100 percent of artworks in international auctions," Samei Azar gushed after the 3 1/2-hour event on June 28. "Iranian society has shown that art can be an investment."

He described many of the buyers as "young and Western educated."

"It was exciting," Samei Azar said. "One-third of buyers were new buyers. It shows the growth potential for Iran's art market."

A new analysis from the World Meteorological Organization says average land and ocean surface temperatures from 2001 to 2010 rose above the previous decade, and were almost a half-degree Celsius above the 1961-1990 global average.

The decade ending in 2010 was an unprecedented era of climate extremes, the agency said, evidenced by heat waves in Europe and Russia, droughts in the Amazon Basin, Australia and East Africa, and huge storms like Tropical Cyclone Nargis and Hurricane Katrina.

Data from 139 nations show that droughts like those in Australia, East Africa and the Amazon Basin affected the most people worldwide. But it was the hugely destructive and deadly floods such as those in Pakistan, Australia, Africa, India and Eastern Europe that were the most frequent extreme weather events.

Experts say a decade is about the minimum length of time to study when it comes to spotting climate change.

From 1971 to 2010, global temperatures rose by an average rate of 0.17 degrees Celsius per decade. But going back to 1880, the average increase was .062 percent degrees Celsius per decade.

The pace also picked up in recent decades. Average temperatures were 0.21 degrees Celsius warmer this past decade than from 1991 to 2000, which were in turn 0.14 degrees Celsius warmer than from 1981 to 1990.

Natural cycles between atmosphere and oceans make some years cooler than others, but during the past decade there was no major event associated with El Nino, the phenomenon characterized by unusually warm temperatures in the equatorial Pacific Ocean. Much of the decade was affected by the cooling La Nina, which comes from unusually cool temperatures there, or neutral conditions.

Given those circumstances, WMO Secretary-General Michel Jarraud says the data doesn't support the notion among some in the scientific community of a slowdown, or lull, in the pace of planetary warming in recent years.

"The last decade was the warmest, by a significant margin," he said. "If anything we should not talk about the plateau, we should talk about the acceleration."

Jarraud says the data show warming accelerated between 1971 and 2010, with the past two decades increasing at rates never seen before amid rising concentrations of industrial gases that trap heat in the atmosphere like a greenhouse.

By the end of 2010, the report shows, atmospheric concentrations of some of the chief warming gases from fossil fuel burning and other human actions were far higher than at the start of the industrial era in 1750. Carbon dioxide concentrations measured in the air around the world rose 39 percent since then; methane rose 158 percent; and nitrous oxide was up 20 percent.

Of course, has blistered most of the Southwest in recent days where highs of 115 to120 degrees over parts of Arizona, Nevada and California occurred this past weekend; the temperature at California's Death Valley actually approached 130 degrees.

With such punishing heat as this, it may be shocking to hear that today at 11 a.m. EDT (1500 GMT), the Earth reached the point in its orbit where it is in space. During aphelion, as it is called, the Earth will be 94,508,959 miles (152,097,426 kilometers) from the sun, or 3,106,399 miles (4,999,264 km) farther as compared to when the Earth was closest point to the sun (called perihelion) last New Year's Day. The difference in distance is 3.287 percent, which makes a difference in radiant heat received by Earth of nearly 7 percent. []

A climatological fallacy

If you ask most people in which month of the year they believe that the most probably would say were closest during June, July or August. But our warm weather doesn't relate to our distance from the sun. It's because of the 23.5-degree tilt of the Earth's axis that the sun is above the horizon for different lengths of time at different seasons. The tilt determines whether the sun's rays strike us at a low angle or more directly.

At the latitude of Chicago for instance, the more nearly direct rays at the of June 21 bring about three times as much heat as the more slanting rays at the winter solstice on Dec. 21. Heat received by any region is dependent on the length of daylight and the angle of the sun above the horizon. Hence the noticeable differences in temperatures that are registered over different parts of the world.

The Earth, sun and seasons

It would seem logical to assume that because Earth is farthest from the sun in the July and closest in December, that such a difference would tend to warm the winter and cool the summer at least in the Northern Hemisphere. The seasons are reversed in the Southern Hemisphere, where winter is currently under way.

And yet the truth of the matter is that the preponderance of large land masses in the Northern Hemisphere works the other way and actually tends to make the winters colder and the summers hotter.

Interestingly, the times when the Earth lies at its closest and farthest points from the sun roughly coincide with two significant U.S. holidays. We're closest to the sun around New Year's Day and farthest from the sun around Independence Day. Actually, depending on the year, the date of perihelion can vary from Jan. 1 to 5; the date of aphelion can vary from July 2 to July 6.

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

AX-3-DOMAINES, France (Reuters) - Chris Froome faced the inevitable questions about doping at the Tour de France after demolishing his rivals to claim the overall lead and said his results would not come under suspicion in the future.

Briton Froome won Saturday's eighth stage, a 195-km mountain ride from Castres, to lead overall by 51 seconds from Team Sky colleague Richie Porte with Spain's Alejandro Valverde in third place 1:25 off the pace.

His dominant performance was reminiscent of the way the disgraced rider Lance Armstrong would hammer the field in the first mountain stage of the Tour before controlling the rest of the race with often sterling performances in the time trials.

Asked to confirm his performances had nothing to do with banned substances, Froome said: "One hundred percent. I think it's normal that people ask questions in cycling given the history of the sport.

"I know the sport has changed. There's absolutely no way I'd be able to get these results if the sport had not changed.

"Results now are definitely a lot more credible. The questions should be asked about people who were winning races maybe five, 10 years ago when we know doping was more prevalent."

While 2012 champion Bradley Wiggins last year lost his cool when grilled about doping and angrily hit out at accusations made on Twitter, Froome remained calm.

"For me it is a bit of a personal mission to show that the sport has changed," he said.

"I certainly know that the results I get are not going to be stripped 10, 20 years down the line. That's not going to happen."

Last year, American Armstrong was stripped of his seven Tour titles, won from 1999-2005, for doping and then admitted in a television interview in January he had taken performance-enhancing drugs.

Just as the translator finished saying Froome's words in French, the rider took the microphone again and continued: "Anyone who actually spends a bit of time with the team, with us... see that this is months and months of preparation - going to these training camps in altitude all together, the support off the bike from the sport staff, from my fiance, this is so much preparation that it's not wow', it does add up."

(Editing by Alison Wildey)