Genetic analysis of tonic immobility in young Japanese quail (Coturnix cotunix japonica)

Data were obtained on tonic immobility from 10th-generation matings of replicated lines of Japanese quail. These lines had been selected for high and low mating ability and included the random-bred control population from which the selected lines originated. At 6, and again at 12 days of age, each bird was subjected to uniform procedures of immobilization and was given two scores, one indicating the number of trials required to induce immobility, another the duration of induced immobility. Although there were no differences between sexes, lines were significantly different for duration and percentage incidence to the immobility response at both ages. Individuals that responded faster also exhibited longer durations of immobility, suggesting a high degree of susceptibility. Heritability estimates indicate that the additive genetic variation effecting tonic immobility is low to moderate in magnitude. These results, when taken in an evolutionary context, suggest prior natural selection for tonic immobility and indicate that this trait is associated with fitness.     

Learningwith media: Restructuring the debate

Mark E. Davidson is deceased.     

International Council for Educational Media (formerly ICEF)

In contrast to the sultry weather of last year's Assembly in Lisbon, autumnal sunshine and a nip in the air greeted the large number of delegates to the 19th General Assembly held in Stockholm from 22–26 September, 1969. The last time the Conference was held in Stockholm was June 1957. Those attending this year were keen to see and hear of the rapid advances made in equipment supply and teaching methods in the twelve years' interval. They were not disappointed.     

Towards a More Appropriate University English Curriculum in China in the Context of English as an International Language

The rapid and wide spread of English has given rise to its lingua franca status, which in turn, changes the nature of English and English teaching at the tertiary level. This paper, based on a survey, discusses some of the problems with the current English curriculum used in Chinese universities and proceeds to offer some suggestions for a more appropriate university English curriculum in China in the context of English as an international language.     

Tracking of Physical Fitness Components from Childhood to Adolescence: A Longitudinal Study

ABSTRACT

Childhood physical fitness relative to adult health outcomes coupled with scant longitudinal research indicates that tracking of fitness components throughout childhood/adolescence is imperative. The study examined the stability/tracking of 9 measures of fitness for boys and girls at 5 points throughout childhood/adolescence. Tracking coefficients between individual fitness measures at various age comparisons were calculated. Using a sample with recorded data at 4 time-points, tertiles (high, moderate, low) were calculated for each fitness measure for boys and girls. Stability of fitness measures was calculated. Boys outperformed girls on fitness measures at most time points. Significantly low to moderately high tracking coefficients for each fitness measure at all time points for boys (r = .21-.79) and girls (r = .23-.89) were found. Tertile ratings remained stable across the 4 time-points. Findings highlight the importance of developing healthy fitness behaviors early in life and the significance of intervention during adolescence in low-fit youth.