Buffering effect of positive parent–child relationships on adolescent risk taking: A longitudinal neuroimaging investigation

Adolescence is marked by a steep increase in risk-taking behavior. The serious consequences of such heightened risk taking raise the importance of identifying protective factors. Despite its dynamic change during adolescence, family relationships remain a key source of influence for teenagers. Using a longitudinal fMRI approach, we scanned 23 adolescents twice across a 1.5-year period to examine how changes in parent–child relationships contribute to changes in adolescent risk taking over time via changes in adolescents’ neural reactivity to rewards. Results indicate that although parent–child relationships are not associated with adolescent risk taking concurrently, increases in positive parent–child relationships contribute to declines in adolescent risk taking. This process is mediated by longitudinal decreases in ventral striatum activation to rewards during risk taking. Findings highlight the neural pathways through which improvements in positive parent–child relationships serve to buffer longitudinal increases in adolescent risk taking.     

Family relationships and the development of social competence in adolescence

Abstract Resilient adolescents are notable for their social competence, which enables them to form and maintain close relationships. The evidence is that adolescents' social competence is derived from their experience of close relationships within their family. On the basis of structured interviews, adolescents' working models of attachments can be categorized into secure, dismissive, or pre-occupied. These attachment styles are associated with very divergent beliefs about the self and others, with differing patterns of emotion regulation and with differing risk profiles for maladjustment. Parenting styles and family relationships appear to have considerable influence on attachment behaviour. Further evidence for the importance of the family comes from research on ego development. Family level behavioural patterns have been discerned from family research interviews which are associated with stagnation or advancement in ego development during adolescence. Though the results suggest causal connections, the direction of effects is far from clear. Longitudinal research underpins the importance of childhood temperament as a contributing factor to the quality of the family environment that the child and then adolescent experiences.     

Learning to Observe Relationships and Coping

Milieu relationships provide the critical background presence to staff's attempts to motivate, regulate, and teach patients how to cope with stress. Forging a connection with hospitalized children and adolescents demands attention to how they respond to adults and engage with staff around milieu expectations. Assessment guides that deal with these issues are presented. Important aspects of children's relatedness are presented in the context of their working models of adults and the influence of these representations on their response to staff. Coping skills are explained with particular emphasis on behavioral coping strategies. Tied to the assessment process are interventions that emphasize staff's role in helping patients manage strong affects and avoid the use of nonproductive behavior regulation strategies.     

Synthesis and Antitumour Activity of New Derivatives of Flavone-8-acetic Acid (FAA). Part 2: Ring-Substituted Derivatives

A range of 18 derivatives of flavone-8-acetic acid (FAA) with substituents on the 2-phenyl group have been prepared and their anti-tumour activity evaluated in vitro against a panel of human and murine tumour cell lines and in vivo against MAC 15A. There was no clear-cut relationship between in vitro and in vivo activity but the activity in each situation was found to be very sensitive to the precise substitution pattern with closely related isomers giving widely different activities. Some of the compounds, notably 10b,cj , and r , were active in vivo and these require further studies in order to evaluate their potential for development.     

N-ω-Carbethoxypentyl-4-quinolones: A New Class of Leukotriene Biosynthesis Inhibitors

6-[(4-Quinolinyl)oxy]hexanoic acids and the corresponding esters were designed and synthesized as inhibitors of the production of arachidonic acid metabolites. The inhibitory activities were assayed in vitro by evaluation of serum leukotriene B₄ and thromboxane B₂ production. While all 6-[(4-quinolinyl)oxy]hexanoic acids and their esters proved to be inactive, the N-alkyl-4-quinolones, obtained as by-products in their synthesis, were found to be a new class of leukotriene biosynthesis inhibitors.     

An estimate of phylogenetic relationships among culicine mosquitoes using a restriction map of the rDNA cistron

Restriction maps of the rDNA cistron of twelve species of mosquitoes in six genera of the subfamily Culicinae were constructed using eight 6 bp recognition restriction enzymes. Anopheles albimanus was used as an outgroup. The size of the rDNA cistron ranged from 8.5 kb in Aedes katherinensis to 12.9 kb in Ae. polynesiensis. A total of twenty-six sites were scored; eighteen were polymorphic among ingroup taxa. The proportion of polymorphic nucleotide sites (Pnuc) was 0.059 and the heterozygosity per nucleotide site (Hnuc) was 0.028. Wagner and Fitch Parsimony, Dollo Parsimony and Nei-Li distance/neighbour-joining methods were used to construct phylogenetic trees. The rDNA RFLP dataset did not provide a well-supported phylogeny among culicine taxa. The RFLP phylogenies are incongruent with the morphology character based and molecular phylogenies and derived relationships did not correspond with current taxonomic classifications. The lack of resolution was due to homoplasy arising from frequent independent loss or gain of restriction sites among unrelated taxa.     

Synthesis and cytotoxic activity of new alkyl[3-(2-chloroethyl)ureido]benzene derivatives

Several alkyl[3-(2-chloroethyl)ureido] (CEU) benzene derivatives were prepared as potential anticancer agents. These new compounds were readily prepared in good yields by addition of anilines to 2-chloroethylisocyanate. Their cytotoxic activity was evaluated on human breast cancer (MDA-MB-231), human colon adenocarcinoma (LoVo) and mouse lymphocytic leukemia (P388D₁) tumor cell lines. Several new CEUs were significantly more cytotoxic than the nitrogen mustard chlorambucil. The biological activity of these aromatic urea derivatives seems to be related to the nature and position of the alkyl substituents on the aromatic ring. Substitution by branched alkyl groups on position 4 of the aromatic ring led to cytotoxic molecules which are up to 5 times more potent than the standard chlorambucil.