Dorianna Twersky, Editor Emerita of Nuclear Fusion, passed away on 22 January 2010.Dorianna was Editor of Nuclear Fusion for nearly two decades, from 1967 to 1985. During her tenure, the journal underwent an impressive development. In 1967 Nuclear Fusion was a quarterly with 300 pages published each year, by 1978 it had become a monthly journal. Reflecting the developments in the field, it had evolved from a general plasma physics journal to one that was far more fusion relevant. Dorianna ensured that Nuclear Fusion had a strong peer review system and that effective journal policies were developed and adhered to.Dorianna drove the success of the journal. Her dynamic personality and commitment to the international fusion community underpinned that success. She had a well deserved reputation for toughness and for critical and intuitive thinking. Perhaps her most valuable trait was her persuasiveness and ability to motivate people to help with the journal and contribute to its development. She was able to inspire a sense of dedication and enthusiasm in the people she worked with and was highly respected.Dorianna Twersky will be greatly missed.Four of the prominent scientists who served on the Nuclear Fusion Board of Editors during Dorianna's Editorship have written a few lines in her memory: Professor Dmitri Ryutov, Professor Folker Engelmann, Professor Jim Callen and Professor Karl Lackner."Dorianna Twersky was one of the best journal editors who I have met during my half-century in physics and plasma physics. An author and a referee would immediately sense that she was a friendly and open-minded person who would always try to resolve conflicts in a constructive way. That was the time well before the emergence of the Internet, and the paper correspondence added a personal touch to the journal business. Sometimes she would add a handwritten joke, or a small cartoon at the corner of her letter.Dorianna spoke perfect Russian. That was of significant help to a large group of authors from the Soviet Union, quite a few of whom didn't know English at all. She helped them at all the stages of the editorial process.Dorianna served as an Editor at the time that can be called The Golden Age of plasma physics, with a continuous influx of new ideas and exciting experimental results. There was a general sense of fast progress towards controlled fusion. At the end of her tenure, the biggest world tokamaks started producing the first plasmas. For those who knew her, her name will remain inseparable from the times of great accomplishment and fast progress in fusion." Dmitri Ryutov"Dorianna Twersky was an extraordinary personality. She combined intuition for taking right decisions in complex matters outside her personal experience with an inexhaustible energy to push things forward and the capability to impose her view, once taken, on people irrespective of their standing without hurting them. Because of these abilities, Dorianna really was Nuclear Fusion for many years. It was a great privilege for me to have known her as an author first, and also to have been able to work with her later on as a referee and member of the Board of Editors of the journal." Folker Engelmann"Dorianna Twersky was a very remarkable woman who somehow was able to establish Nuclear Fusion as one of the first truly international journals and the most successful scientific journal within the IAEA and she kept it moving forward for three decades through all the trials and tribulations of the Cold War era. She made excellent use of her Board of Editors, on which I was privileged to serve. Her passing marks the end of the era during which fusion grew to become a mature international research program, with considerable help from her outstanding editorship of Nuclear Fusion during the critical early growth period." Jim Callen"It is difficult to do justice to Dorianna in a few sentences, she was truly a larger-than-life personality and most things one would like to write are in danger of being misunderstood. I honestly believe that authors and referees were keeping to promised deadlines, because they would have been afraid of a disapproving glance from her. The fact that the journal was blossoming under her leadership is true, but this would be said of course in nearly any obituary.If I try nevertheless to distil my admiration for her into an objective-sounding statement, I would point to the fact that she consistently made technically correct decisions regarding matters in which she had no direct personal know-how. The way she worked this miracle was based on an extraordinary capability to judge people: she knew exactly whom to trust to what percentage." Karl Lackner