Background: Invasion of these invasive plants in the ecosystem threatens the habitat of endemic species, reduces biodiversity, and causes a disturbance in the ecological system. Hypochaeris radicata L. (Asteraceae), the most invasive plant in Korea, particularly in Jeju Island, invades farmlands, and autochthonous forests, resulting in the establishment of monocultures and modification of the ecosystem structure. Methods and Results: In this study was, we evaluated the biological activity of 70% ethanolic extracts from different parts of Hypochaeris radicata L. The biological activities of 70% ethanolic extracts of different parts, such as flower, leaf, stem, and root, of H. radicata were investigated. The total polyphenol content was highest in flower extracts (50.82 ± 3.16 ㎎ · GAE/g). In addition, the highest flavonoid content was observed in flower extract (15.19 ± 2.03㎎ · QE/g). The flower extract of H. radicata exhibited stronger DPPH radical-scavenging activities, ABTS radical scavenging activities, and reducing power than the other parts. The flower extract of H. radicata was observed to have the highest tyrosinase and α-glucosidase inhibitory activities. Conclusions: The flower extracts of H. radicata exhibited remarkable antioxidant activity as well as tyrosinase and α-glucosidase inhibitory effects. These activities might be related to the phenolic compounds present in the H. radicata flower extract.

This study was to assess Korean sailors' knowldege, attitudes and behaviors about AIDS. The subjects of this study were 379 safety-trainee sailors. Data were collected by self reporting on a questionnaire during February to March 1996. The results were as follows : The mean score on AIDS knowledge was 17.3 out of a possible maximum score of 24.0. With respect to diseas transmission , only 45.6-86.5percent of the sailors correctly indicated that causal contact does not lead to contraction AIDS. The younger, unmarried , and educated groups had a higher level of knowledge about AIDS. With respect t sailors' attitudes about ADIS, 85.2 percent of the sailors reported that the AIDS is as big a problem as the media suggested, and over half of the sailors(53.8%) reported that they are being afraid of getting AIDS. One attitude, which was most pervasive(903.1 percent agreeing) was that it is important for sailors to receive AIDS education as a part of social education classes. In attitudes , there was statistical significance by age group, marital statistical signifiacance by age group , marital status, and educational level. With respect to sailor's preventive behaviors about AIDS, the mean score was 7.1 out of a possible maximum score of 9.0. It was shown that the older age, married groups had a higher level of preventive behaviors about AIDS.