The World Indoor Athletics Championships get under way here Thursday with the credibility of track and field on the line as the sport grapples with the fallout from the worst doping scandal in its history.
The four-day meeting is the first global championships to take place since Russian athletes were banned from competition last year after a devastating World Anti-Doping Agency (WADA) report which detailed evidence of systemic doping.
Five other nations -- Ethiopia, Morocco, Kenya, Ukraine and Belarus -- have also been given a stern warning by the International Association of Athletics Federations (IAAF) that they need to clean up their acts or face suspension.
Months of tumultuous headlines have left the IAAF chiefs battling to restore the sport's integrity as more than 600 athletes from around 200 nations gather in Portland for this week's championships.
Russia's ban means the country will not be able to defend the three titles won at the last World Indoor Championships in Poland two years ago -- the men's and women's triple jump and the women's high jump.
Another gold medallist from Sopot -- Sweden's Abeba Aregawi -- will also be missing, after testing positive for the newly banned endurance-boosting drug meldonium -- the substance involved in tennis star Maria Sharapova's case.
- Star names -
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It will be left to some of the sport's biggest names to provide respite from the gloomy off-field headlines when the action gets under way at the Oregon Convention Center on Thursday evening (local time).
France's reigning Olympic pole vault champion Renaud Lavillenie gets the ball rolling when he attempts to win back the crown he last won at the 2012 Indoors in Istanbul.
The world record holder arrives in Oregon in good form, having cleared the six-metre mark twice in recent weeks.
However Lavillenie faces stiff competition in an event bristling with talent, with Brazil's Thiago Braz, Canada's reigning world champion Shawn Barber and Greece's defending champion Konstadinos Filippidis all expected to feature in the hunt for medals.
On the track, Dutch sprinting queen Dafne Schippers will
be out to lay down a marker in the women's 60m as she builds towards the Olympics in Rio de Janeiro in five months time.
The 23-year-old from Utrecht switched her focus to sprinting from the multi-event discipline of the heptathlon two years ago, a decision which paid rich dividends last year when she powered to victory in the 200m final at the World Championships in Beijing.
The main threat to the Dutch flier's chances of striking gold in Portland is expected to come from Barbara Pierre of the United States, who matched Schippers' season-best time of 7.0secs when she romped to victory at the US National Indoor championships last weekend.
- Golden oldies? -
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The battle to find the fastest man in the world over 60m will feature some of the youngest and oldest competitors on the sprinting circuit.
Jamaican veteran Asafa Powell is the man to beat, with the 33-year-old holding the fastest time in the 60m this year posted by athletes competing in Portland, clocking 6.49secs.
Evergreen St Kitts and Nevis sprinter Kim Collins meanwhile is back at the ripe old age of 39.
At the other end of the spectrum is rising American star Trayvon Bromell, the 20-year-old 2015 World Championships bronze medallist in the 100m who was a baby when Collins competed in his first Olympics at the 1996 Atlanta Games.
Bromell forms a trio of American runners including 2014 world indoor silver medallist Marvin Bracy and World Indoor Tour winner Mike Rodgers.
Elsewhere, home hopes will be carried by world record holder Ashton Eaton, with the Olympic decathlon champion chasing a hat-trick of indoor golds in the heptathlon, after victories in 2012 and 2014.
