Obituary: Josef van Ess (1934–2021)

Obituary for Jan Valentyn van der Merwe

Professor Jan Valentyn Van der Merwe passed away on Friday, 25 September, at the age of 71. Prof Jan’s illustrious career began after he completed a research fellowship at Duke University in the USA, and returned to South Africa as Head of the Department of Obstetrics and Gynaecology at Pretoria University. In this role, Prof Jan pioneered the establishment of an assisted reproduction unit in S...

Josef Richter

Obituary

ESS patterns: adding pairs to an ESS.

The notion of a pattern of evolutionarily stable strategies was introduced by Cannings and Vickers in 1988 (J. Theor. Biol. 132:387-420). In this paper a specific class of patterns is considered. Suppose that there is an evolutionarily stable strategy (ESS) on some set of n strategies {1,2,...,n} and that new strategies {n + 1,n + 2,...,n + k} are added. Supposing that for this new enlarged con...

Arguments in English Josef

Despite the idiosyncratic properties of null-complement phenomena observed by Fillmore (1986), Lambrecht and Lemoine (2005), and others, many researchers have pursued large-scope, single-factor explanations of the distributional and interpretive restrictions on null complements—in particular, explanations based on Aktionsart (Rappaport Hovav and Levin 1998) and selectional restrictions (Resnik ...