Abstract How many chess rooks or queens does it take to guard all squares of a given polyomino, the union square tiles from grid? This question is version art gallery problem in which guards can “see” whichever rook queen attacks. We show that $$\lfloor {\frac{n}{2}} \rfloor $$ ⌊n<mml...

T HE four articles included in this special section of the Journal of Gerontology: Psychological Sciences present cutting-edge research on the nature, causes, and consequences of negative aspects of close relationships in adulthood. There is an extensive body of research demonstrating that support from social relationships provides benefits for psychological wellbeing and physical health (Anton...