Question: Scott Andrew Buchholz, is an Australian politician, he previously served as chief of staff to which Queensland Senator Australian politician, who has served as the Deputy Prime Minister of Australia since 18 February 2016?

Context paragraphs:
Julia Gillard: Julia Eileen Gillard, {'1': ", '2': ", '3': ", '4': "} (born 29 September 1961) is a former Australian politician who was the 27th Prime Minister of Australia from 2010 to 2013, as Leader of the Australian Labor Party.  She was previously the 13th Deputy Prime Minister of Australia, and held the cabinet positions of Minister for Education, Minister for Employment and Workplace Relations and Minister for Social Inclusion from 2007 to 2010.  She was the first and to date only woman to hold the positions of deputy prime minister, prime minister and leader of a major party in Australia.

Warren Truss: Warren Errol Truss (born 8 October 1948) is a former Australian politician who served as the 16th Deputy Prime Minister of Australia and Minister for Infrastructure and Regional Development in the Abbott Government and the Turnbull Government.  Truss served as the federal leader of the National Party of Australia (The Nationals) between 2007 and 11 February 2016 when he announced his decision to retire and not contest the 2016 federal election.  He was the member of the House of Representatives for Wide Bay from the 1990 election until his retirement in May 2016.  Following the merger of the Queensland branches of the Nationals and Liberals, Truss was re-elected in 2010 for the Liberal National Party.

Swedish governmental line of succession: The Swedish constitution of 1974 allows the Prime Minister of Sweden to appoint one of the Ministers in the cabinet as Deputy Prime Minister ("biträdande statsminister", also unofficially known as "vice statsminister", "Vice Prime Minister"), in case the Prime Minister for some reason is prevented from performing his or her duties.  However, if a Deputy Prime Minister has not been appointed, the Minister in the cabinet who has served the longest time (and if there are several with equal experience the one who is oldest) takes over as head of government.  Note that the person acting as Prime Minister does not do so on a permanent basis: if a Prime Minister dies, resigns or loses a vote of confidence in the Riksdag, the Speaker of the Riksdag will then confer with the parties of the Riksdag and propose a new Prime Minister, who must be tolerated by a majority of the Riksdag.  If the Prime Minister has resigned or lost a vote of confidence, he or she will remain the head of a government "ad interim" until the new Prime Minister assumes his or her office.  The only case where the governmental line of succession becomes relevant is when the Prime Minister dies (upon which the person next in the line of succession serves as the head of a government "ad interim") or when the Prime Minister is on leave or for any other reason incapable of serving, but still remains in office.  This might be compared to the Presidential line of succession in the United States, where the person next in line assumes the Presidency throughout the remainder of the term if the President dies, resigns or is impeached.

Scott Buchholz: Scott Andrew Buchholz (born 27 March 1968) is an Australian politician.  He has been the Liberal National Party of Queensland (LNP) member of the new Australian House of Representatives seat of Wright since the 2010 federal election.  He previously served as chief of staff to Queensland Senator Barnaby Joyce and was a director of CQX Group of Transport Companies for 18 years.  He also occupied the unwinnable sixth spot on the Liberal/National Senate ticket in Queensland at the 2007 election, attracting 290 votes.

Moses Ali: General Moses Ali (born 5 April 1939) is a Ugandan politician and retired general.  He is the First Deputy Prime Minister and Deputy Leader of Government Business in Parliament.  He was appointed to that position on 6 June 2016.  He previously served in the Cabinet of Uganda as Third Deputy Prime Minister and Deputy Leader of Government Business from May 2011 until June 2016.  He has also been the elected Member of Parliament for East Moyo County in Adjumani District since 2011.

Deputy Prime Minister of Singapore: The Deputy Prime Minister of the Republic of Singapore is the deputy head of the government of the Republic of Singapore.  The role of Deputy Prime Minister is the second highest post and senior Cabinet Minister in Singapore.  The holder will sometimes assume the role of Acting Prime Minister when the PM is temporarily absent from Singapore.  Since the mid-1980s, Singapore has usually had two Deputy Prime Ministers at a time.  Only Ong Teng Cheong and Tony Tan (who later became Singaporean presidents) served under more than one Prime Minister during their time as Deputy Prime Minister.

Sergei Ivanov: Sergei Borisovich Ivanov (Russian: Серге́й Бори́сович Ивано́в ; ] ; born 31 January 1953) is a Russian senior official and politician.  Ivanov was Minister of Defense of Russia from March 2001 to February 2007, Deputy Prime Minister from November 2005 to February 2007, and the First Deputy Prime Minister from February 2007 to May 2008.  After the election of Dmitry Medvedev as President of Russia, Ivanov was reappointed a Deputy Prime Minister in Vladimir Putin's second government.  From December 2011 to August 2016, Ivanov was the Chief of Staff of the Presidential Executive Office.

Barnaby Joyce: Barnaby Thomas Gerard Joyce (born 17 April 1967) is an Australian politician who has served as the Deputy Prime Minister of Australia since 18 February 2016, as the Leader of the National Party of Australia since 11 February 2016, and as the Minister for Agriculture and Water Resources since 21 September 2015.  He was sworn in as Minister for Agriculture in the Abbott Government on 18 September 2013.  Water Resources was added to his portfolio on 21 September 2015 in the Turnbull Government.

Paul Keating: Paul John Keating (born 18 January 1944) is an Australian politician who was the 24th Prime Minister of Australia and the Leader of the Labor Party from 1991 to 1996.  Keating represented the division of Blaxland in the Australian House of Representatives and served as Minister for Northern Australia in the Whitlam government and as Treasurer of Australia and the 7th Deputy Prime Minister of Australia in the government of Bob Hawke.

Fiona Nash: Fiona Joy Nash (née Morton; born 6 May 1965) is an Australian politician.  She has represented the National Party of Australia in the Australian Senate for the state of New South Wales since 1 July 2005 and has served as the Deputy Leader of the Nationals in the Parliament of Australia since 11 February 2016, having previously served as the party's deputy Senate leader since 2008.

Supporting paragraphs: Scott Buchholz Barnaby Joyce
Answer: Barnaby Joyce