Greater Number Of Days Research Articles

Discrimination learning and stimulus generalization in rats with hippocampal lesions

Rats with hippocampal lesions and sham operated control animals were trained on a go-no-go tone discrimination. For half of the animals of each group the tone was the positive stimulus while for the other half the tone was negative. The hippocampal tone negative group took the greatest number of days to learn the task. Tone generalization tests administered the day after the learning criterion was reached did not yield any differences in either excitatory or inhibitory stimulus control between the hippocampal and sham animals.

Maintenance of luteal function in rats by rat prolactin.

SummaryAdministration of prolactin to hypophysectomized rats maintains luteal function. When rat and sheep prolactins were given at the same dose (IU) rat prolactin was found to maintain luteal function for a greater number of days. This duration exceeded the length of pregnancy in the rat.

Oddity-reversal and delayed-response performance of monkeys previously exposed to focal-head irradiation.

Control monkeys and monkeys with previous focal-head exposure to x radiation, some with irradiation of the frontal association areas and some with irradiation of the posterior association areas, were tested both on an oddity- reversal problem which required the utilization of the same stimulus cues in antagonistic response pattems for correct solution and on spatial delayed- response problems. With respect to the oddity-reversal problem, a statistically significant increase in both errors and days to criterion on reversal learning over errors and days to criterion on original learning was found. The radiation groups differed significantly with respect to days to criterion, but not with respect to errors to criteria, the frontal irradiates requiring the greatest number of days and the posterior irradiates the least. A significant groups by conditions interaction was found in the days to criterion analysis. This interaction was interpreted as meaning that the amount of increase in days to criterion on reversal learning was significantly greater for the frontal irradiates than for either of the other two groups. These results are diagnostic of neural tissue damage in the frontal focal-head irradiated monkeys. With respect to delayed-response testing, no significant differences were found. These results do not suggest neuralmore » tissue damage in the frontal focal-head irradiated monkeys. These findings are discussed in terms of their possible value for fauure study of the functions of the frontal lobes. (auth)« less

Atmospheric Pollution

THE twenty-fourth report on “Atmospheric Pollution” issued by the Department of Scientific and Industrial Research appears in a new format and in two volumes, namely, the report on observations up to March 31, 1938 (H.M. Stationery Office, 2s. net) and the other a supplement giving deposit tables over the same period (H.M. Stationery Office, 4s. 6d. net). This arrangement will be a convenience to those who are interested in the general results rather than the actual observations. These show that there has been a tendency for the air to become cleaner. Again Cardiff provides the lowest figure for sooty matter and many will learn-with surprise that the London area provides some of the worst figures. Greenwich had the greatest number of days with heavy smoke haze. Stoke followed next and then Victoria Street, London.

Health and Physical Efficiency of City Teachers

The health and physical efficiency of teachers have generally been considered as dependent upon such school conditions and teaching factors as size of classes, length of experience, age and sex of teachers, salary, marital relations, type of school, and the like. But what published data is there to support these opinions? Has it been proved that those who teach more than forty pupils' are subject to a greater number of days of disabling illness during the year than those who teach fewer pupils? Is it known to what extent age and length of experience occasion ill health? Does the type of school tend to determine the amount of sickness to be found annually among teachers, as was indicated in a report made in Cleveland by the Director of Reference and Research? For example, is the hazard of teaching in an elementary school greater than that of teaching in a high school or in a kindergarten ? Does the type of community bear any relation to the number of days of sick leave required during the year? These and many other questions concerning the health of teachers' and teaching factors await answers supported by concrete data.

Financing public education in the southern states

The most fundamental problem, as well as the one most difficult to solve, confronting school administrators is that of securing an approximation of adequate funds for the maintenance of schools. This is particularly the most difficult problem throughout the Southern States. Ayres, in his rating of state school systems,1 which has occasioned so much discussion, placed the Southern States almost without exception in the lowest fourth of the states of the Union in In determining this ranking, about half of his estimates, or five points out of the ten considered, were upon fiscal items. Of some of the other five items, such as of school term, there is a positive correlation between the amount of money expended and the length of school term provided. The states which expended a large amount per unit for education were the states which provided the greatest number of days of school; and, conversely, the states which expended the least were the states which provided the fewest days of school. Further, it seems entirely in keeping with the logic of the educational situation to assume that the financial factor was in large part responsible for the relationship found to exist among these other factors, and to conclude that finance is the most fundamental problem to be attacked in order to bring the rank of the Southern States more nearly to a position comparable to those which Ayres has ranked as the most progressive states. The most profitable attitude which can be maintained regarding these low ranks is that which seeks the cause for this lack of expenditure and the resulting lack of the other attributes of educational efficiency. The two questions the answers to which are most needed are: (1) What are the causes for this lack of expenditure? (2) What remedies can be suggested? It is natural to inquire first: To what extent are economic conditions responsible for this lack of expenditure? The economist would say that the measure of a state's ability to pay is found in its income and not in its general property wealth. The student of educational

A Commercial Geography of Foreign Nations

THIS book will not assist to make commercial geography a scientific study. Like the geographical books of old time, the volume consists largely of disconnected details which no pupil ought to be asked to remember, and which produce weariness of the flesh in the unfortunate reader. If commercial geography means what Mr. Bovn makes it, then it is the duty of all who are anxious for the introduction of reasonable methods of instruction in schools to condemn it at every opportunity. Here are a few examples of unqualified or loose statements which occur in the early pages of the book. “The greatest heat for the greatest number of days is on the Equator” (p. 1). “As the Equator is neared [from the Tropics] two days have vertical sunshine at each point within the Tropics, approaching gradually to the autumn and vernal equinoxes at the Equator ” (p. 1). “Added to the effects of the neighbouring land or water are the similar effects of the winds that blow over them” (p. 2). “The Gulf Stream washes the coast of Norway” (p. 11). But we do not object so much to statements of this kind as to the principle of cramming pupils with information which has to be accepted without inquiry and cannot be assimilated. The less we have of commercial geography of this kind the more likely are we to create an interest in the study of the subject.