Temperament,classmate likability,and social perspective coordination as correlates of children's parent-rated type A behaviors

Parents of 58 boys and 62 girls from grades three through eight completed the Matthews Youth Test for Health (MYTH), a measure of Type A behavior. Normative and reliability data were similar to those obtained from teachers as reported in the literature, but a factor analysis of parents' ratings revealed four factors (Competitiveness, Irritability, Impatience, and Leadership) as opposed to the two factors (Impatience/Aggression and Competitiveness) that have been derived from teacher ratings. Boys had higher total MYTH scores than girls, but correlations with age were not significant. No grade or gender effects were obtained for any of the four MYTH factor scores. Correlates of the MYTH scores were computed separately for boys and for girls. For boys, Irritability was related to Reactivity, a Difficult Temperament, low classmate Likeability, and poor performance on two social cognitive tasks (compromising and friendship understanding). For girls, Leadership was related to Classmate Likeability and good performance on the two social cognitive tasks. For boys only, total MYTH scores were related to low Attention Span, high Reactivity, a Difficult Temperament, and low Friendship Understanding scores. Findings are related to the gender differences found in the study of both ego control and cooperation/ competition.     

Race effects in modifying cognitive impulsivity through self-instruction and modeling.

Seven-year-old children, identified as impulsive on the basis of MFF performance, were given a training program intended to modify their impulsivity through modeling and self-instruction. All the subjects were of comparable intelligence, social class, geographic residence, and were matched on sex. The 40 experimental subjects were paired on the basis of race. Half the pairs were trained by white models and half by black models. While the results do not provide unequivocal support for the effectiveness of such training, they do demonstrate selective changes in impulsivity based upon racial similarities of models and subjects. The construct validity of the MFF as a measure of reflection-impulsivity and the relevance of social class membership is discussed.     

Mental addition in third,fourth, and sixth graders

Research on mental arithmetic has suggested that young children use a counting algorithm for simple mental addition, but that adults use memory retrieval from an organized representation of addition facts. To determine the age at which performance shifts from counting to retrieval, children in grades 3, 4, and 6 were tested in a true/false verification task. Reaction time patterns suggested that third grade is a transitional age with respect to memory structure for addition—half of these children seemed to be counting and half retrieving from memory. Results from fourth and sixth graders implicated retrieval quite strongly, as their results resembled adult RTs very closely. Fourth graders' processing, however, was easily disrupted when false problems were presented. The third graders' difficulties are not due to an inability to form mental representations of number; all three grades demonstrated a strong split effect, indicative of a simpler mental representation of numerical information than is necessary for addition. The results were discussed in the context of memory retrieval versus counting models of mental arithmetic, and the increase across age in automaticity of retrieval processes.     

维生素D_3及其受体的临床意义

1,25-(OH)2D3是维生素D在体内发挥生理作用的活性形式。活性维生素D3通过与细胞内特异性维生素D受体结合,除了具有调节钙磷代谢的功能外,还发现其可预防和治疗骨质疏松、心血管疾病、自身免疫性疾病和一些肿瘤等。然而,维生素D缺乏在人群中非常普遍。     

The relationship between vocational interest differentiation and career undecidedness

Fifty-four female and thirty male students over 20 years old were administered the Career Decision Scale and the six occupational scales of the Vocational Preference Inventory in order to test the hypothesis that indecision is negatively related to occupational interest differentiation in an adult population. Interest differentiation did not appear to be a reliable indicator of vocational undecidedness.