RESUMO
The anesthetic effects of clove-oil-derived eugenol were studied in the zebrafish, Danio rerio (Hamilton). Acute lethality and the effects of exposures to various dosages of eugenol were measured. The estimated 96-h LC50 for eugenol was 21 ppm. Times to induction and recovery from anesthesia were measured and compared with MS-222 under similar conditions. Eugenol induced anesthesia faster and at lower concentrations when compared to MS-222. The recovery times for fish exposed to eugenol were generally longer compared to similar concentrations of MS-222. Doses of 60-100 ppm eugenol produced rapid anesthesia with an acceptably short time for recovery. These findings suggest that eugenol could be an effective anesthetic for use with this species, and when compared to MS-222, its benefits include a lower cost, lower required dosage, improved safety, and potentially lower mortality rates.
RESUMO
Students in 93 university classes described themselves and their instructors on personality tests measuring traits relevant (ascendancy and personal relations) and irrelevant (sociability and cautiousness) to teaching skill. Dissimilarity (instructor being higher than student) on relevant trait dimensions was hypothesized to be instrumental for student satisfaction with an instructor's role performance. When students were classified as similar or dissimilar to their instructors on the personality dimensions, those most attracted to their instructors were those dissimilar on relevant (but not irrelevant) traits. The dissimilarity finding was not an artifact of differences in skill of instructor nor of differences in students' perceptions of their instructors' traits. A three-dimensional system was devised to specify when similarity and dissimilarity should promote attraction.
