Species-specific, age-varying plant traits affect herbivore growth and survival.

Seasonal windows of opportunity represent intervals of time within a year during which organisms have improved prospects of achieving life history aims such as growth or reproduction, and may be commonly structured by temporal variation in abiotic factors, bottom-up factors, and top-down factors. Although seasonal windows of opportunity are likely to be common, few studies have examined the factors that structure seasonal windows of opportunity in time. Here, we experimentally manipulated host-plant age in two milkweed species (Asclepias fascicularis and Asclepias speciosa) in order to investigate the role of plant-species-specific and plant-age-varying traits on the survival and growth of monarch caterpillars (Danaus plexippus). We show that the two plant species showed diverging trajectories of defense traits with increasing age. These species-specific and age-varying host-plant traits significantly affected the growth and survival of monarch caterpillars through both resource quality- and quantity-based constraints. The effects of plant age on monarch developmental success were comparable to and sometimes larger than those of plant-species identity. We conclude that species-specific and age-varying plant traits are likely to be important factors with the potential to structure seasonal windows of opportunity for monarch development, and examine the implications of these findings for both broader patterns in the ontogeny of plant defense traits and the specific ecology of milkweed-monarch interactions in a changing world.

Consumers leading public consultation: the general public's knowledge of stroke.

BACKGROUND: The need to make health services and research relevant to the general public through user involvement and consultation has been recognized and formalized in guidelines and research publications. OBJECTIVES: We had the following objectives (i) to involve and enable lay people to identify and direct a research study as co-researchers consulting members of the general public about their awareness and knowledge of stroke and stroke risk; and (ii) to consult members of the general public aged between 40 and 65 years old to identify what they know about the signs of stroke and potential risk factors in order to inform local public health programmes. METHODS: A 20-point multiple choice questionnaire was designed by two consumers trained in research skills at a year long training programme. The questionnaire was sent to 250 randomly selected patients from one general practice in North Staffordshire. RESULTS: A 57% response rate was achieved (142 out of 250), with 139 being appropriate for analysis. The current knowledge and awareness of stroke and stroke risk was relatively good. Almost 90% knew that stroke occurs in the brain and most correctly identified the causes as related to impaired blood supply to the brain. Further, upon recognizing signs of stroke, 96% thought it was 'extremely important' to get immediate treatment for someone who may be having a stroke. Seventy-eight percent of respondents stated that they would like further information about stroke. The most popular sources of information identified were: their general practice (51%); television and radio (36%); and friends and family (33%). CONCLUSION: The consumers' involvement has essentially allowed lay people to consult other members of the general public about health issues of national priority with specific local relevance. The involvement of consumers in research needs to be considered as worthwhile if it is to have any lasting impact on local or national services. Future research using consumer involvement will need to decide upon the balance between scientific integrity and the level of consumer direction.