Predictors and protective factors for adolescent Internet victimization: results from a 2008 nationwide Danish youth survey.

AIM: To examine the rate of Internet victimization in a nationally representative sample of adolescents aged 14-17 and to analyze predictors and protective factors for victimization. METHODS: Data were collected for 3707 pupils in Danish schools in 2008, using a multimedia computer-based self-interviewing programme. Family characteristics, alcohol and drug abuse, exposure to physical/sexual abuse, emotional problems, social conduct and own risky Internet behaviour were included in the analyses. RESULTS: Any online victimization was reported by 27% of the adolescents, most frequently a rumour spread online (9% of boys and 15% of girls) and sexual solicitation (5% of boys and 16% of girls). Parental surveillance of adolescents' Internet use significantly reduced their risk of online victimization. Roughly half of the adolescents had met Internet acquaintances face to face, with few instances resulting in forced sex (five boys and nine girls). Female gender, parental physical violence, previous exposure to sexual abuse, alcohol abuse in the family, self-reported emotional problems and antisocial behaviour and high Internet use were all weakly and risky online behaviour strongly associated with online victimization. CONCLUSIONS: Danish adolescents are generally aware of the principles of 'safe chatting'; however, online harassment is relatively frequent, but offline victimization based on Internet acquaintances is rare.

Parental violence and adolescent mental health.

Being the target of parental violent acts decreases child adjustment and increases the likelihood of mental health problems in childhood and adolescence. Our study analyses how different types of parental violence ranging from verbal threats and swearing to hitting and kicking a child, are associated with child adjustment, indicated by strengths and difficulties scale (SDQ) total problem score, internalizing and externalizing problems as well as prosocial behaviour. We also study whether girls and boys and youths in two Nordic countries respond differently to parental violence. The data consists of a large-scale community sample of 15-16-year old Finnish (n = 5,762) and Danish (n = 3,943) adolescents. The representative data of continental Finland and its Finnish and Swedish speaking ninth graders as well as representative data of Danish ninth grade pupils were collected by the Police College of Finland and in Denmark by the National Institute of Public Health, University of Southern Denmark. The results show a clear dose-response effect between parental violent behaviour and the adolescent's problems. The more severe forms of parental violence were associated with higher levels of SDQ total difficulties and internalizing and externalizing symptoms. There was also a connection between parental violence and the deterioration of prosocial behaviour. The association was gender and nationality specific. The findings imply a high prevalence of parental violence and adverse mental health among the affected Finnish and Danish adolescents. Though the laws have been set in motion to prevent the use of parental physical violence the challenges remain in several domains of child protection, general health care, prevention and intervention.

1H nuclear magnetic resonance studies of the conformations of vitamin D compounds in various solvents.

Using proton NMR, the solution conformation of the A ring of vitamin D3 and its analogs has been studied by application of the Karplus relation to the observed coupling constants. The A-ring conformations of vitamins D3, D2, and 25-hydroxyvitamin D3 were found to be solvent dependent, with a clear preference for an equatorial hydroxyl group in polar solvents such as methanol and dimethyl sulfoxide. Conversion of the hydroxyl group to an acetate did not affect solution conformation appreciably, but the corresponding t-butyl-dimethylsilyl ether derivative of vitamin D3 showed a strong preference for the 3 beta-equatorial conformer. The A-ring conformation of the active hormone, 1,25-dihydroxyvitamin D3, which has two hydroxyl groups competing for the equatorial position, was found not to be solvent-dependent.