| the incidence of rheumatoid arthritis is predicted by rheumatoid factor titer in a longitudinal population study. | rheumatoid factor (rf) is often detected in subjects who do not have rheumatoid arthritis (ra). to determine if the presence of rf is predictive of the development of ra, 2,712 pima indians of arizona, 20 years of age or older, initially without ra, have been observed for up to 19 years with biennial examinations. these included a medical history, physical examination of the joints, radiographs, and rf determination by sheep cell agglutination test. during the study period, 70 new cases of ra de ... | 1988 | 3178905 |
| behavioral consequences of innate preferences and olfactory learning in hawkmoth-flower interactions. | spatiotemporal variability in floral resources can have ecological and evolutionary consequences for both plants and the pollinators on which they depend. seldom, however, can patterns of flower abundance and visitation in the field be linked with the behavioral mechanisms that allow floral visitors to persist when a preferred resource is scarce. to explore these mechanisms better, we examined factors controlling floral preference in the hawkmoth manduca sexta in the semiarid grassland of arizon ... | 2008 | 18305169 |
| potential oversummering and overwintering regions for the wheat stripe rust pathogen in the contiguous united states. | epidemics of wheat stripe rust, caused by puccinia striiformis f. sp. tritici (pst), are more frequent in the regions where pst can oversummer and overwinter. regions for potential oversummering and overwintering of pst were determined in the contiguous united states using a survival index (si) ranging from 0 (most unfavorable) to 10 (most favorable) developed based on long-term weather data. the pathogen can survive in cool summer in the most regions north of latitude 40°n, particularly washing ... | 2014 | 23722926 |
| california, arizona laws permit medical use of marijuana. | | 1997 | 9117801 |