Attachment representation as predictor of internalizing problems in middle childhood

Problem: The current study examines the relationship between the representation of attachment relationship with mother and internalizing problems in the developmental period of middle childhood. The purpose of the study was to analyze whether the quality of attachment predicts the intensity and seriousness of internalizing problems in middle childhood; and to examine whether the models are gender-specific. Methods: Participants in this study were 151 children aged 9-12 (M = 11.21), 77 boys and 74 girls, recruited from elementary schools in Nitra region. Children completed measures assessing the quality of attachment representation of the relationship with mother (selfreport questionnaire Security Scale), the tendency to react anxiously (self-report questionnaire Childen´s Manifest Anxiety Scale – CMAS), social anxiety (self-report questionnaire Scale of Classical Social Situational Anxiety – KSAT) and depression (self-report questionnaire Children´s Depression Inventory – CDI). Results: Regression analysis indicated that secure attachment representation is a significant negative predictor of children's internalizing problems – manifest anxiety (ß = -.324, p 0.05 and ß = -.194, p > 0.05, respectively), but in the sample of girls, secure attachment representation was a significant negative predictor of both depressive symptoms (ß = -.296, p < .05 for Negative Mood; and ß = -.285, p < .05 for Anhedony). Other models, except for social anxiety, were statistically significant for both samples. In the sample of girls, the predictor accounted for 26.3% of variance in Negative Self Esteem (ß = -.512; p < .001), 18.9% of variance of the total of depression symptoms (ß = -.435; p < .001), 10.9% of variance in Ineffectiveness (ß = -.331; p < .05) and 10.5% of variance in manifest anxiety (ß = -.324; p < .05). The results were similar for the sample of boys. Attachment security accounted for 17.4% of variance in Negative Self Esteem (ß = -.435; p < .001), 11.3% of variance of the total of depression symptoms (ß = -.377; p < .05) and 10.5% of variance in manifest anxiety (ß = -.332; p < .05). Representation of attachment relationship with mother accounted for less then 10% of variance when predicitng Negative Mood, Anhedony and Interpersonal Problems in both samples, and in addition Inefectiveness only in boys. Additional statistical analyses revealed that regression coefficients across models did not differ. Results suggest that mother is still a primary attachment figure in middle childhood for both, boys and girls, but the quality of attachment to father can also be an important factor of particular adaptive behavior, especially in boys. Because of lack of knowledge and empirical evidence, the future research in the field of gender-specific models of adjustment in middle childhood is needed. Discussion: When interpreting the results of this investigation, it is important to be aware of several limitations. The methodics used in the study are all based on the subjective self-report. The character of the assessment can lead to the tendency to react according to the social expectations. In future studies, it would be beneficial to gather reports about the internalizing problems from children as well as from significant others, and to use multiple attachment assessment (e.g. the combination of questionnaires and projective techniques. Conclusion: We can conclude that attachment representation to mother is an important factor of adaptive development in middle childhood. Our results are in concordance with attachment theory and empirical evidence of associations between violated confidence of availability of attachment figure resulting in insecure attachment representation and maladjustment

Friendship quantity and quality as predictors of rejection sensitivity in adolescents

The current study examines friendship quality and quantity as unique predictors of rejection sensitivity in adolescents. The purpose of the study was to analyze whether the unique contributions of friendship quality and quantity differ in adolescent boys and girls. Rejection sensitivity is conceptualized as the disposition to anxiously expect, readily perceive and intensively react to social rejection. That is why rejection sensitivity is considered to be a cognitive-affective mechanism which leads to increase of internalizing problems in children and adolescents (loneliness, social anxiety, depression...). Friendship variables have been found to predict the level of internalizing problems in adolescents. Little to no research, however, has examined friendship quality and quantity as predictors of level of rejection sensitivity. Participants in this study were 184 students (98 girls and 86 boys), aged from 13 to 16 (M=13.83, SD=1). Adolescents completed measures assessing number of their friends, quality of best friendship (self-report questionnaire Friendship qualities scale, Bukowski, Hoza, Boivin, 1994) and rejection sensitivity (self-report questionnaire Rejection sensitivity scale, Downey, Feldman, 1996). Regression analysis indicated that friendship features (companionship, balance, help, security, closeness), friendship quantity and overall friendship quality are significant unique predictors of sensitivity rejection in adolescents with. Results suggest that adolescents with higher number of and higher quality friendships have lower concerns about the possibility and expectation of rejection, which can lead to minimizing the risk of development of internalizing problems. However, only a small proportion of variance was accounted for in rejection sensitivity by the friendship variables (small to medium effect size). This suggests that different kind of peer relationships (peer acceptance, popularity, peer victimization) make unique, differential (greater or lesser) contributions to rejection sensitivity. Different types of peer relations can moderate and mediate each other´s influence on specific types of internalizing problems in adolescents. The future research simultaneously examining more types of peer relationship is needed. There has been empirical evidence that girls have more quality friendships which provide them more emotional and instrumental support, than for boys. Our results support this empirical evidence. Regression analysis indicated, that balance (large effect size), help, security and closeness in friendship (small to medium effect size) and overall friendship quality (medium effect size) are significant unique predictors of rejection sensitivity for adolescent girls, but not for boys. Results suggest that predictors of sensitivity rejection in boys are other than interpersonal factors, for example personal or coping strategies. Further directions in research are discussed

Prussian Blue acts as a mediator in a reagentless cytokinin biosensor

An electrochemical biosensor for detection of the plant hormone cytokinin is introduced. Cytokinin homeostasis in tissues of many lower and higher plants is controlled largely by the activity of cytokinin dehydrogenase (CKX, EC 1.5.99.12) that catalyzes an irreversible cleavage of N(6)-side chain of cytokinins. Expression of Arabidopsis thaliana CKX2 from Pichia pastoris was used to prepare purified AtCKX2 as the basis of the cytokinin biosensor. Prussian Blue (PrB) was electrodeposited on Pt microelectrodes prior to deposition of the enzyme in a sol-gel matrix. The biosensor gave amperometric responses to several cytokinins. These responses depended on the presence of both the enzyme and the Prussian Blue. Thus Prussian Blue must act as an electron mediator between the FAD centre in CKX2 and the Pt surface