Question: Alexander Goldfarb has been associated with a Russian nuclear physicist who is also an activist for what causes?
Context: Alexander Davidovich Goldfarb (a.k.a. Alex Goldfarb, Russian: Александр Давидович Гольдфарб ) (born 1947 in Moscow) is a Russian-American microbiologist, activist, and author.  He emigrated from the USSR in 1975 and lived in Israel and Germany before settling permanently in New York in 1982.  Goldfarb is a naturalized American citizen.  He has combined a scientific career as a microbiologist with political and public activities focused on civil liberties and human rights in Russia, in the course of which he has been associated with Andrei Sakharov, George Soros, Boris Berezovsky, and Alexander Litvinenko.  He has not visited Russia since 2000. Yuri Tsolakovich Oganessian (Russian: Юрий Цолакович Оганесян ; born 14 April 1933) is a Russian nuclear physicist of Armenian descent, who is considered the world's leading researcher in superheavy chemical elements.  He led the discovery of the these elements elements in the periodic table.  He succeeded Georgy Flerov as director of the Flerov Laboratory of Nuclear Reactions at the Joint Institute for Nuclear Research in 1989 and is now its scientific leader.  The chemical element Oganesson (Og, atomic number 118) was named after him in 2016. Yuri Alexeyevich Trutnev (Russian: Ю́рий Алексе́евич Тру́тнев ) (born November 2, 1927, Moscow) is a Soviet-Russian physicist who is known for his involvement in the development of the AN602 hydrogen bomb (or Tsar Bomba), the most powerful nuclear weapon ever detonated.  Its October 30, 1961 test remains the most powerful artificial explosion in human history, about 50 megatons, Tsar Bomb.  Since the 1990s, he has been the Director of the VNIIEF Russian Nuclear Labs, located at the Nizhni-Novgorod Oblast, Sarov.  Trutnev is a member of the Russian Academy of Science, Doctor of Technical Sciences, and Hero of Socialist Labor (1962). Kirill Dmitriyevich Sinelnikov (1901–1966) was a Russian nuclear physicist of world renown, considered the greatest organizer of science the USSR has ever had.  The Sinelnikov Prize for outstanding works in the field of physics is named after him. Alexander Isaakovich Shlyakhter (Russian: Александр Исаакович Шляхтер , died June 2000) was a Russian nuclear physicist and risk analyst. Alexander Nikolayevich Skrinsky (Скринский, Александр Николаевич)(born 15 January 1936) is a Russian nuclear physicist. Death of a Dissident: The Poisoning of Alexander Litvinenko and the Return of the KGB is a book written by Alexander Goldfarb and Marina Litvinenko about the life and death of her husband, former FSB officer Alexander Litvinenko who was poisoned by the radioactive element polonium in London in November 2006. Rosatom State Atomic Energy Corporation (Russian: Росатом ; ] ) is a state corporation (non-profit organization) in Russia, established in 2007, the regulatory body of the Russian nuclear complex.  It is headquartered in Moscow.  Rosatom runs all nuclear assets of the Russian Federation, both civilian and military, totaling over 360 business and research units, including all Russian nuclear icebreaker ships.  Along with commercial activities which move forward nuclear power and nuclear fuel cycle facilities, it acts as a governmental agent, primarily in the field of national security (nuclear deterrence), nuclear and radiation safety, basic and applied science.  Besides, it has the authority to fulfill on behalf of the Russian Federation the international commitments undertaken by the nation with regard to the peaceful use of atomic energy and non-proliferation. Andrei Dmitrievich Sakharov (Russian: Андре́й Дми́триевич Са́харов ; 21 May 192114 December 1989) was a Russian nuclear physicist, dissident, and activist for disarmament, peace and human rights. Konstantin Petrzhak (alternatively Pietrzak; Russian: Константи́н Анто́нович Петржак ; ] ; 1907–1998) was a Soviet–Russian nuclear physicist and university professor of Polish origin.  He discovered spontaneous fission of uranium with Georgy Flyorov in 1940; in addition, he also aided in Soviet Union's atomic bomb project .
Answer: disarmament, peace and human rights