1,207 research outputs found
Dynamical Equations from a First-Order Perturbative Superspace Formulation of 10D N=1 String-Corrected Supergravity (I)
Utilizing a first-order perturbative superspace approach, we derive the
bosonic equations of motion for the 10D, N = 1 supergravity fields. We give the
Lagrangian corresponding to these equations derived from superspace geometry.
Moreover, the equivalence of this Lagrangian to the first-order perturbative
component level Lagrangian of anomaly-free supergravity is proven. Our
treatment covers both the two-form and six-form formulations.Comment: 20 pages, no figures, references and note in proof adde
A Descriptive Profile of School Board Members in North Carolina
The purpose of this study was to analyze the characteristics of school board members in the public school systems of North Carolina in order to obtain a profile of the typical board member and compile the suggested qualifications as a basis for possible change in the legal requirements for membership on local boards of education. A researcher-designed questionnaire was mailed to all school board members in North Carolina. Responses were received from 309 board members. A descriptive profile of board of education members in the public school systems of North Carolina was developed; determination of legal requirements for board membership was made; and a list of desirable qualifications for board membership as identified by board members was compiled. In testing for significant differences between county boards and city boards, it was concluded that the city board members have a higher level of education, higher income, and are more likely to be members of a minority group than county board members. County board members have lived longer in the community than city board members. There was no significant difference between the number of male and female board members with children in the school system. Recommendations based on the findings suggested that additional study be conducted, utilizing a forced-type of questionnaire
Pollution and Evolution
Three examples, industrial melanism in moths, insecticide resistance in insects, and myxomatosis in Australian rabbits, are used to illustrate the concept that evolution may result from tampering with the physical or biotic environment of a species. Hence, concern about the effects of pollution must encompass not only the possibility of extinction but the possibility of evolution. In the case of harmful species, biological or chemical control measures may result in populations more refractory to control than the original untreated populations
Natural Selection in a Leopard Frog Population
In a population of immature leopard frogs (Rana pipiens) at Mud Lake, Washington County, Minnesota, a high frequency of unilateral deformity of the hind legs was observed in 1965. Metamorphosis from tadpole to frog took place during July, and samples in late July averaged 14.8% deformed frogs. By late September, the frequency of deformed frogs had decreased to 3.6%, presumably as the result of natural selection
Absolute effects of schooling as a reference for the interpretation of educational intervention effects
Knowledge of the absolute effects of schooling provides a useful reference for the interpretation of the effectiveness of educational interventions. We use discontinuities in test scores between the oldest pupils in one birth cohort and the youngest in the next to assess the absolute effects of schooling. Our study includes 90 % of all pupils in year-groups 4–6 of primary education (ages 7–10) in Northern Ireland. Assignment to year-groups is strictly determined by date of birth in Northern Ireland. This creates a situation which parallels randomized controlled experimentation. The findings support the view that the guidelines suggested by Cohen (in 1969) may be overly ambitious when evaluating the effectiveness of educational interventions
Investigation of the Influence of an Orientation Course on Academic Success among Freshman Students
Student Personnel and Guidanc
- …