Given a document, find the main entity about whom the author is writing. Write the full name if mentioned in the text. Note that URLs in the text have been replaced with [Link].
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Question: SACRAMENTO  Calif. (Reuters) -  A California neuroscientist vying to unseat Republican Congressman Dana Rohrabacher  stepped up  his  criticism of the conservative on Tuesday  demanding  he  return a $1 000 contribution from indicted Trump adviser Paul Manafort.
FILE PHOTO:  Republican U.S. Representative Dana Rohrabacher  speaks at a news conference in Moscow  Russia on June 2  2013. REUTERS/Maxim Shemetov/File Photo
The Orange County seat held by  Rohrabacher  is key to Democratsâ hopes to increase their numbers in the U.S. House of Representatives in next yearâs elections. Neuroscientist Hans Keirstead  a stem cell researcher and entrepreneur from Laguna Beach  is one of seven Democrats aiming to beat him  according to the Federal Election Commission.
 Rohrabacher   a senior member of the House Committee on Foreign Affairs  has frequently praised Russian President Vladimir Putin and was considered for a role in U.S. President Donald Trumpâs cabinet.
FILE PHOTO: U.S. Rep. Dana Rohrabacher (R-CA) speaks during a House Foreign Affairs Europe  Eurasia and Emerging Threats Subcommittee hearing about the attack on demonstrators by members of Turkish President Recep Tayyip Erdogan's security detail on Capitol Hill in Washington  DC  U.S. on May 25  2017. REUTERS/Aaron P. Bernstein/File Photo

Answer: Dana Rohrabacher


Question: Shaun White Wins Gold In Halfpipe At The Winter Olympics
Updated at 10:15 p.m.  ET
Shaun White  pulled off a gold-medal comeback in the halfpipe  and Japan's Ayumu Hirano won silver on the strength of a phenomenal second run.
CORRECTION: An early version of this story reported that  White  had won silver — that was reported after the second run had completed. On his third run   White  won gold.
 White  missed out on a medal back in 2014  when  he  was hurt at the Sochi Games.  He 's now the only snowboarder ever to win three gold medals at the Olympics. And  he  did it by winning the 100th gold medal for the U.S. Winter Olympic team.
After the Japanese snowboarder's rousing run  the pressure shifted to James and  White . James seemed to take a very deep breath before he set off on his second run. The first section was great — but he couldn't get a clean landing on one of his final tricks.  White  came out with energy and speed — but  he  fell midway through  and mustered only 55 points.
The situation reversed in the third and final run  when  White  earned a 97.75 and both of  his  top rivals fell during  their  attempts.
This is the second Olympic medal for Hirano; he won silver in Sochi. He is also the reigning X Games champion in the halfpipe  having won that title last month  in a competition that  White  skipped.
 White  led a group of four American snowboarders who qualified for the finals of the men's halfpipe at Phoenix Snow Park in Pyeongchang; joining  him  were Ben Ferguson  Chase Josey  and Jake Pates.
 Ferguson  cleaned up  his  second run after a fall in the first. And after a strong final run earned  him  a 90.75   he  finished 4th; Josey was 6th and Pates was 8th.

Answer: Shaun White


Question: In particular  Trump's conversation with Sessions and subsequent decision to pardon Arpaio could shed new light on Trump's motives in speaking to James Comey  then the FBI director  one day after former national security adviser Michael Flynn resigned about ending the investigation into Flynn.
Specifically  Trump's decision to pardon Arpaio is key to determining his intent in speaking with  Comey  in February about dropping the Flynn investigation and then firing  Comey  in May after  he  refused to do so  said Renato Mariotti  a former federal prosecutor.
How  Comey  fits in
According to  Comey 's testimony before the Senate Intelligence Committee in June  Trump privately told  Comey   who was spearheading the FBI's Russia probe at the time  "I hope you can let this go " referring to the Flynn investigation.
Several Trump allies and Republican lawmakers have since said that those words do not prove Trump tried to obstruct justice by asking  Comey  to drop the investigation and subsequently firing  him .
Sen. Jim Risch of Idaho  for instance  zeroed in on the statement during  Comey 's testimony.
After reading out loud  Comey 's recollection of Trump's statement  Risch said  "He did not direct you to let it go."
"Not in his words  no "  Comey  replied.
" He  did not order you to let it go " Risch said.
 He  later asked  Comey  whether  he  knew "of any case where a person has been charged for obstruction of justice or  for that matter  any other criminal offense  where this â they said  or thought  they hoped for an outcome?"
When  Comey  said  he  took Trump's words as a direction from the president of the United States  Risch said  "You may have taken it as a direction  but that's not what he said."
Moreover  despite statements from Trump's allies and administration officials who painted Trump's comments to  Comey  as musings and not as a direct order  Arpaio's pardon suggests "that he was serious about ending investigations as to his friends" and that it wasn't "just idle talk."
"The obstruction of justice would flow from the entire landscape of Trump's behavior: telling  Comey  to back off on the Flynn investigation  firing  him  when  he  wouldn't  and then admitting on national television that  he  dismissed  Comey  because of the Russia investigation " Ohlin told Business Insider.
 He  said that Trump's telling Russian officials in the Oval Office that  Comey  was "a real nut job" and that firing  him  had taken "great pressure" off of  him  added weight to the inference that Trump used  his  executive authority to fire  Comey  to stymie a federal investigation.

Answer:
James Comey