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1.
Harleen Mangat Tajamul Hussain C Sundaram MP JS Anandaraj 《Indian journal of clinical biochemistry : IJCB》2002,17(2):74-79
Poly A RNA status and itsin vitro translation in a rabbit reticulolysate cell free system, were assessed in the skeletal muscle of young boys with Duchenne
muscular dystrophy. Compared to normals there is a significant 48% increase in poly A RNA content of dystrophic muscle and
its translatability was increased by 56% based on35S methionine incorporation into total protein systhesised. Immunoprecipitation of the translated products with monospecific
antibodies showed that there is a 2.6 fold and a 2 fold increase in m and μ calpains respectively. This underlines the importance
of both synthetic and degenerative activities in the early pathology in DMD muscle. 相似文献
2.
Robert N. Emde Robert Plomin JoAnn Robinson Robin Corley John DeFries David W. Fulker J. Steven Reznick Joseph Campos Jerome Kagan Carolyn Zahn-Waxler 《Child development》1992,63(6):1437-1455
200 pairs of twins were assessed at 14 months of age in the laboratory and home. Measures were obtained of temperament, emotion, and cognition/language. Comparisons between identical and fraternal twin correlations suggest that individual differences are due in part to heritable influences. For temperament, genetic influence was significant for behavioral observations of inhibition to the unfamiliar, tester ratings of activity, and parental ratings of temperament. For emotion, significant genetic influence was found for empathy and parental ratings of negative emotion. The estimate of heritability for parental report of expression of negative emotions was relatively high, whereas that for expression of positive emotions was low, a finding consistent with previous research. For cognition and language, genetic influence was significant for behavioral indices of spatial memory, categorization, and word comprehension. Shared rearing environment appears influential for parental reports of language and for positive emotions, but not for other measures of emotion or for temperament. 相似文献
3.
Age-related Asynchrony of Knowledge and Action 总被引：1，自引：0，他引：1
Children's ability to act in accordance with rules was assessed in 2 experiments. Experiment I included 66 children, aged 31, 33.5, or 36 months, who performed 2 tasks. In a forced-choice, deductive sorting task, children were told 2 rules (if-then statements) and then required to use the rules to sort items. A knowledge task tested children's knowledge about which rule's antecedent condition held true for each item. Rules were either based on natural categories (e.g., vehicles vs. musical instruments) or ad hoc categories (e.g., things found inside the house vs. things found outside). Children in the 2 younger age groups performed better on the knowledge task than on the sorting task. The 36-month-olds performed equally well on both tasks. In Experiment 2, groups of 12 32.25-month-olds received either the knowledge task, the sorting task, or a mnemonically supported version of the sorting task. The group that received the knowledge task performed better than the other groups, which did not differ. This result undermines the possibility that differential performance on the knowledge and sorting tasks is due to a difference in memory demand. Taken together, the results of Experiments 1 and 2 imply a relatively rapid, age-related change culminating in the ability to execute systematically rules that require access to extant knowledge. 相似文献
4.
Genetic Change and Continuity from Fourteen to Twenty Months: The MacArthur Longitudinal Twin Study 总被引：3，自引：0，他引：3
Robert Plomin Jerome Kagan Robert N. Emde J. Steven Reznick Julia M. Braungart JoAnn Robinson Joseph Campos Carolyn Zahn-Waxler Robin Corley David W. Fulker J. C. DeFries 《Child development》1993,64(5):1354-1376
Genetic change as well as continuity was investigated within the domains of temperament, emotion, and cognition/language for 200 pairs of twins assessed at 14 and 20 months of age in the laboratory and home. The second year of life is marked by change rather than continuity: correlations from 14 to 20 months averaged about .30 for observational measures of temperament and emotion, about .40 for language measures, and about .50 for mental development. 2 types of genetic change were examined: changes in the magnitude of genetic influence (heritability) and genetic contributions to change from 14 to 20 months. In general, heritability estimates were similar at 14 and 20 months. Evidence for genetic influence on change from 14 to 20 months emerged for several measures, implying that heritability cannot be equated with stability. Analyses of continuity indicated that genetic factors are largely responsible for continuity from 14 to 20 months. 相似文献
5.
Delayed response performance was assessed in 120 7-, 9-, and 11-month-old infants with correct response defined as either retrieval of a hidden object or gaze toward the location where the object was hidden. Performance improved with age, was above chance for each age group in each condition, and was more often correct with the gaze response. When direction of gaze and reach differed, direction of gaze was more likely to be correct. Infants in the reach condition were more likely to fail to reverse a previously correct response (i.e., to make the A-not-B error). Perseverative responding occurred frequently and was more likely in the reach than the gaze condition. This effect emerged primarily in the context of an incorrect response, which suggests modality-specific sensitivity to the effect of priming rather than reinforcement. Many infants showed strong side biases, and there was a tendency for more reaches to the left but gazes to the right. In a second experiment, 12 5-month-olds gazed toward the correct location more frequently than would be expected by chance but failed to reverse a previously correct response more often than older infants. These findings indicate that response modality has a significant effect on delayed-response performance. 相似文献
6.
The development of visual expectations in the first year 总被引：1，自引：0，他引：1
The development of expectations was investigated by using the Visual Expectations Procedure. In Experiment 1, 128 infants aged 6-, 9-, and 12-months-old saw two 40-trial sequences of a videotaped mechanical toy appearing in various locations. The sequences represented an alternation pattern (i.e., ABAB) or a complex pivot pattern (i.e., ABCBABCB). In Experiment 2, 76 infants aged 4-, 8-, and 12-months-old saw either a left-right alternation or a top-bottom alternation. Reaction time improved and the percentage of anticipations increased between 6 and 9 months in Experiment 1 and between 4 and 8 months in Experiment 2 but not thereafter. Anticipations for the pivot sequence and for younger infants on both sequences were often incorrect (i.e., gaze shifts occurred before stimulus onset but were not directed toward the upcoming stimulus). We conclude that young infants have expectations that reflect some degree of general or procedural knowledge, but it is not clear that this behavior implies specific, articulated expectations about upcoming events. 相似文献
7.
Ritual, Habit, and Perfectionism: The Prevalence and Development of Compulsive-like Behavior in Normal Young Children 总被引：4，自引：0，他引：4
David W. Evans James F. Leckman Alice Carter J. Steven Reznick Desiree Henshaw Robert A. King and David Pauls 《Child development》1997,68(1):58-68
Young children engage in a significant amount of rutualitic, repetitive, and compulsive-like activity that appears to be part of their Normal behavioral repertoire. Empirically, little is known about the onset, prevalence, and developmental trajectory of these phenomena. A parent-report questionnaire, the Childhood Routines Inventory (CRI), was developed to assess compulsive-like behavior in young children, and was administered to 1,492 parents with children between the ages of 8 and 72 months. The CRI has strong overall internal consistency and a distinct two-factor structure. The frequency of compulsive-like behaviors changes with age: Two-, 3- and 4-year-olds engaged in more compulsive behavior than children younger than 1 year of age and older than 4 years of age. Results are discussed from a development psychopathology framework and for their implications for future research in this area. 相似文献
8.
Feldman et al. criticize the MacArthur Communicative Development Inventories (CDIs) as having too much variability, too little stability, and insufficient ability to predict early language delay. We present data showing that these characteristics of the CDI are authentic reflections of individual differences in early language development rather than measurement deficiencies. We also respond to their critical assertions concerning sociodemographic influences on the CDI scores. 相似文献
9.
The physiology and psychology of behavioral inhibition in children 总被引：18，自引：0，他引：18
Longitudinal study of 2 cohorts of children selected in the second or third year of life to be extremely cautious and shy (inhibited) or fearless and outgoing (uninhibited) to unfamiliar events revealed preservation of these 2 behavioral qualities through the sixth year of life. Additionally, more of the inhibited children showed signs of activation in 1 or more of the physiological circuits that usually respond to novelty and challenge, namely, the hypothalamic-pituitary-adrenal axis, the reticular activating system, and the sympathetic arm of the autonomic nervous system. It is suggested that the threshold of responsivity in limbic and hypothalamic structures to unfamiliarity and challenge is tonically lower for inhibited than for uninhibited children. 相似文献
10.
Inhibited and uninhibited types of children 总被引：10，自引：0，他引：10
An initial group of 100 children who were not selected a priori on any behavioral features were observed in laboratory settings at 14, 20, 32, and 48 months and their behaviors coded for inhibition and lack of inhibition to the unfamiliar. The children who had been extremely inhibited or uninhibited at both 14 and 20 months differed significantly at 4 years of age in behavior and cardiac acceleration to cognitive stress. However, for the entire sample, there was no significant relation between degree of inhibited behavior at 14 or 20 months, on the one hand, and inhibition at 4 years of age, on the other, nor any relation between behavior and heart rate acceleration. These results suggest that the constructs inhibited and uninhibited to the unfamiliar refer to children who fall at the extremes of a phenotypic continuum from shyness and restraint to sociability and affective spontaneity. 相似文献