BACKGROUND Little is known about the epidemiology of rhinitis, particularly the perennial and non-allergic forms. The aim of this study was to compare the symptoms, atopic state, and medical history of individuals with seasonal and perennial rhinitis. DESIGN Of 7702 adults aged 16-65 years registered with a London general practice, 2969 (30%) were screened by postal questionnaire. Samples of ...

Our objective was to evaluate the effects of burrowing activities by banner-tail kangaroo rats (Dipodornys spectabilis Merriam) on plant community structure and species dominance for two patch types at the ecotone between shortgrass steppe and desert grassland in New Mexico, USA. 10mounds produced by kangaroo rats were selected in patches dominated by Bo~ireloua gracilis (the dominant in shortg...

Little is known about how cultivation legacies affect the outcome of rehabilitation seedings in the Great Basin, even though both frequently co-occur on the same lands. Similarly, there is little known about how these legacies affect native species reestablishment into these seedings. We examined these legacy effects by comparing areas historically cultivated and seeded to adjacent areas that w...

Many arid grassland communities are changing from grass dominance to shrub dominance, but the mechanisms involved in this conversion process are not completely understood. Aeolian processes likely contribute to this conversion from grassland to shrubland. The purpose of this research is to provide information regarding how vegetation changes occur in an arid grassland as a result of aeolian sed...