Since the 1980s, yellow fever has reemerged across Africa and in South America. The total of 18 735 yellow fever cases and 4522 deaths reported from 1987 to 1991 represents the greatest amount of yellow fever activity reported to the World Health Organization (WHO) for any 5-year period since 1948. There is an excellent vaccine against yellow fever. At present, a high proportion of travelers to...

Many members of the tribe Cardueae are invasive weeds, including yellow starthistle (Centaurea solstitialis L.), one of the most important weeds in the Western United States. We examined the root crowns and stems of yellow starthistle and related plants growing in five countries (Armenia, Republic of Georgia, Greece, Russia, and Turkey) where yellow starthistle is native. In its native range, t...

The yellow gene family is intriguing for a number of reasons. To date, yellow-like genes have only been identified in insect species and a number of bacteria. The function of the yellows is largely unknown, although a few have been associated with melanization and behavior in Drosophila, and a unique clade of genes from Apis mellifera may be involved in caste specification. Here, we show that y...