Endosperm is emerging as a system for investigating the genetic control of wall placement and deposition in plant development. Development of endosperm progresses in distinct stages from a wall‐less syncytial stage to a cellular stage that is entirely typical of plant meristems where the division plane is predicted by a preprophase band of microtubules (PPB) and cytokinesis is completed by formation of a cell plate in association with a phragmoplast. Four developmentally different types of walls, each associated with a different (...) microtubule system, are sequentially produced: (1) free growing walls deposited in the absence of mitosis and phragmoplasts; (2) walls guided by cytoplasmic phragmoplasts formed adventitiously in the absence of mitosis; (3) walls formed by interzonal phragmoplasts in a cell cycle that lacks PPBs; and (4) wall deposition driven by interzonal phragmoplasts in a cycle that includes PPBs. We are using methods of differential screening to isolate cDNA clones corresponding in temporal and spatial pattern to the types of wall development, and are studying mutants for clues to the genetic controls of wall development. (shrink)

Next SectionIn an online study conducted separately in the UK and the US, participants rated the acceptability and fairness of four interventions: two types of financial incentives and two types of medical interventions. These were stated to be equally effective in improving outcomes in five contexts: weight loss and smoking cessation programmes, and adherence in treatment programmes for drug addiction, serious mental illness and physiotherapy after surgery. Financial incentives were judged less acceptable and to be less fair than medical interventions (...) across all five contexts. Context moderated the relative preference between rewards and penalties: participants from both countries favoured rewards over penalties in weight loss and treatment for serious mental illness. Only among US participants was this relative preference moderated by perceived responsibility of the target group. Overall, participants supported funding more strongly for interventions when they judged members of the target group to be less responsible for their condition, and vice versa. These results reveal a striking similarity in negative attitudes towards the use of financial incentives, rewards as well as penalties, in improving outcomes across a range of contexts, in the UK and the USA. The basis for such negative attitudes awaits further study. (shrink)