This paper presents an algorithm for computing an equilibrium of an extensive two-person game with perfect recall. The method is computationally efficient by virtue of using the sequence form, whose size is proportional to the size of the game tree. The equilibrium is traced on a piecewise linear path in the sequence form strategy space from an arbitrary starting vector. If the starting vector ...

7,000 plant species for food but today around 20 species provide 90 per cent of the global human diet. Of the 7,100 varieties of apple recorded in America a century ago, 6,800 have now been lost. And there are worries, for example, that the maize staple in southern Africa may be under increasing challenge from climate change. Svalbard provides " the last line in the defence against the extincti...

Most theories explaining how animals form preferences for their actions agree upon a basic outline: animals discover what is preferable through interactions with the world, store this information in memory, and recall it to help them decide what to do in a new situation. However, no single theory currently explains both how preferences are learned, and how they are recalled in a way that is com...

A random sample of 724 individuals across the United States were mailed a questionnaire containing demographic information, an abridged version of the Traumatic Events Survey (D. M. Elliott, 1992), and questions regarding memory for traumatic events. Of these, 505 (70%) completed the survey. Among respondents who reported some form of trauma (72%), delayed recall of the event was reported by 32...