Showing papers by "University of Maryland, Baltimore County published in 1970"

Gliding motility mutants of Myxococcus xanthus.

Abstract: Two gliding motility mutants of Myxococcus xanthus are described. The semimotile mutant (SM) originated by high-frequency segregation from the motile FBt strain. Segregation was enhanced by acridine dye treatment. SM cells glide only when apposed to other cells in a swarm. The nonmotile strain (NM) originated by mutation from SM. NM cells neither glide individually nor cooperatively. FBt, SM, and NM are indistinguishable with respect to fine structure, vegetative growth rate, glycerol-induced microcyst formation, spheroplasting, bacteriophage sensitivity, and responses to light. The motility mutants are more resistant to penicillin and more sensitive to actinomycin D than is the gliding wild type. The NM mutant is also a morphogenetic mutant; it is unable to form fruiting bodies.

Psychedelic Therapy (Utilizing LSD) with Cancer Patients

Abstract: (1970). Psychedelic Therapy (Utilizing LSD) with Cancer Patients. Journal of Psychedelic Drugs: Vol. 3, LSD. The Psychedelic Experience and Beyond, pp. 63-75.

Teacher Expectancy and Mathematics Achievement.

Abstract: Recent research by Rosenthal (1966) and others has demonstrated that the phenomenon of experimenter bias (E-bias) exists in group classroom situations as well as in psychological laboratories (Rosenthal & Fode, 1963). For a concise summary of the more important one-experimenter, one-subject studies the reader is referred to Dayton (1967) and to Kintz, Delparto, Mette, Persons, and Schappe (1965). Experimenter bias is defined as the research situation in which an experimenter, despite standardized procedures, elicits from his subjects outcomes in agreement with prior, externally induced, expectations. The typical paradigm for the one-experimenter, one-subject studies involved a photo face-rating task, with graduate students as experimenters and undergraduates as subjects. Various experimenters were led to expect their subjects to rate photographs toward a specified end of a rating scale continuum. Generally in these studies, experimenters obtained results in accord with their expectancies. The subjects were not aware of the expectancies, and in fact were usually randomly assigned to treatment groups. In extending the study of the E-bias phenomenon to a classroom setting, Rosenthal (1966) randomly sampled 20% of the pupils in each of 18 elementary school classes. The teachers were informed that these pupils had scored unusually high on a test predictive of "academic blooming" (Rosenthal, 1966, p. 409). At the end of the school year all of the pupils were retested with the same test used previously, actually a standardized intelligence test. For most grades and ability levels, the "identified" pupils scored higher than the remainder of the class. Rosenthal concluded that E-bias existed in the classroom situation, that the teacher was usable as an experimenter, and that standardized intelligence test scores were subject to manipulation through mediation of the E-bias phenomenon (teacher expectancies).