Brain weights correlate with behavioral parameters in individual inbred mice housed in a common and enriched environment

Fifty 8-week-old Balb/c mice were individually identified and housed together in a large and enriched environment for 5 months. Maze and open field exploration, response to an aversive noise, swimming, and induced grooming tests were applied to each mouse in an initial search for possible relationships between brain morphology and spontaneous behavior in isogenic individuals living in a complex social and physical environment. The tasks generated 39 quantitative behavioral indices which include locomotion, rearing, still, and grooming bout frequencies, latencies, total, and mean bout durations. At the end of the tests, the 7-month-old mice were sacrificed and the fresh weights of their whole brain, cerebellum, brain stem, diencephalon, telencephalon, and prosencephalon were rapidly obtained. Behavioral data have wide variations and do not adjust to normal population distributions. Means of the same parameter differ between tests. A Spearman correlation matrix of all data yielded many significant correlations between indices of the same task which can be interpreted in terms of time budget and sequence probability. Significant correlations between indices of different tests suggest diverse emotionalities, exploratory strategies, and motor skills. The correlations between body and brain weights and among separate brain regions were not significant. There were several low but significant correlations between brain weights and behavioral indices. Such correlations, the resulting factors, and significant behavioral differences between mice with large and small brains suggest that mice displaying low motor activity in novel environments have larger brains and forebrain/hindbrain ratios than mice with high activity, and that animals with high scores of some specific behaviors have larger brain areas physiologically related to such behaviors.(ABSTRACT TRUNCATED AT 250 WORDS)     

A representation theorem for languages with generalized quantifiers through back-and-forth methods

We obtain in this paper a representation of the formulae of extensions ofL by generalized quantifiers through functors between categories of first-order structures and partial isomorphisms. The main tool in the proofs is the back-and-forth technique. As a corollary we obtain the Caicedo's version of Fraïssés theorem characterizing elementary equivalence for such languages. We also discuss informally some geometrical interpretations of our results.     

List of publications: Husserliana (also translations) and Phaenomenologica

List of publications: Husserliana (also translations) and Phaenomenologica     

CO-WORKER IMPLEMENTED JOB TRAINING: THE USE OF COINCIDENTAL TRAINING AND QUALITY-CONTROL CHECKING ON THE FOOD PREPARATION SKILLS OF TRAINEES WITH MENTAL RETARDATION

In two studies, co-workers of persons with disabilities were taught to use coincidental training procedures while completing their own jobs. In Study 1, the effects of coincidental training on the salad-making skills of 3 trainees with mild and moderate mental retardation were evaluated. Coincidental training by co-workers resulted in improved accuracy of the salad-making skills of the trainees. In Study 2, trainees were also coincidentally taught to make quality-control checks of their salads. An alternating treatments and multiple baseline design indicated that the trainees more readily acquired the skills when taught to check the correctness of their work.     

The psychological cost of waiting

The study of any problem involving waiting situations invariably assumes that people dislike having to wait. The analysis of queueing problems usually prescribes that some costs should be associated with the time people spend waiting to be served. These are usually considered to be of an economic nature, though the existence of other costs of a psychological nature is accepted. It is generally accepted that after having to wait for a certain amount of time, anxiety and stress start to build up in an individual, due both to the sense of waste and the uncertainty involved in a waiting situation. This work provides a theoretical basis for analysing this building up process as it occurs during the waiting period. It is proved that, under very general conditions, the resulting psychological stress accumulated during the process is a marginal increasing function of the waiting time, and some strategies to minimise it are developed. The results obtained give theoretical support to the usual assumptions underlying the development of systems to provide “real time” information to people in waiting situations. This is especially important in the operation of public transportation systems. The results also provide theoretical support to the “convex” treatment usually given to the waiting cost function in queueing problems.     

Social structure features in three inbred strains of mice, C57Bl/6J, Balb/cj, and NIH: a comparative study

Some features of social living were investigated in three inbred strains of mice: C57Bl/6j, Balb/cj, and NIH. Five social behaviors--Aggression, Submission, Allogrooming, Social Rest and Rest Alone, as well as Wheel Running Activity--were recorded 2 h daily for a week, in 26 groups of seven male mice living in an enriched environment. Dominants and subordinates among strains shared some behavioral characteristics, but strain contributions upon social structure were also detected. Similarities among strains included the appearance of a single dominant mouse per group rated as the most aggressive, besides from being the animal presented with most Submissions. Allogrooming was more frequent among subordinates than among dominants and subordinates. Differences among strains were that agonistic behavior among subordinates was higher in the Balb/cj and NIH groups than in the C57Bl/6j mice. NIH mice were recorded in Rest Alone more often than mice from the other strains. C57Bl/6j dominants showed higher rates of Wheel Running Activity than subordinates.     

Three-dimensional perspective drawing of two-dimensional functions with microcomputers

In this paper, we present a BASIC program for Apple II series computers that allows the user to obtain perspective drawings of two-dimensional functions of known analytical expression. Also, we outline a procedure for obtaining perspective representations of two-dimensional arrays of data using the same program. The program should run on any computer with graphics mode with only slight modifications in the graphics commands.