Home, school, and community violence exposure and emotional and conduct problems among low-income adolescents: the moderating role of age and sex.

PURPOSE: The purpose of this study is to assess whether violence exposure is associated with emotional/conduct problems, when adjusting for confounders/covariates and controlling for comorbidity, and to investigate interactions between violence exposure and sex and/or age. METHODS: This cross-sectional study evaluated a community-based sample of 669 in-school 11-15-year-olds. A three-stage probabilistic sampling plan included a random selection of census units, eligible households, and target child. Multivariable logistic regression investigated the effect of severe physical punishment by parents, peer victimization at school, and community violence on the study outcomes (adolescent-reported emotional/conduct problems identified by the Strengths and Difficulties Questionnaire/SDQ) when controlling for confounders (resilience, parental emotional warmth, maternal education/unemployment/anxiety/depression) and covariates (age, sex, stressful life events, parental rejection). RESULTS: Considering interactions, emotional problems were associated with community violence victimization among girls, while conduct problems were associated with severe physical punishment among the younger, suffering peer aggression among the oldest, bullying victimization among girls, and witnessing community violence among boys. Desensitization (less emotional problems with greater violence exposure) was noted among the youngest exposed to severe physical punishment and the oldest who witnessed community violence. CONCLUSION: Age and sex are moderators of the association between violence exposure and emotional/conduct problems. Interventions at local health units, schools, and communities could reduce the use of harsh physical punishment as a parental educational method, help adolescents deal with peer aggression at school and keep them out of the streets by increasing the usual five hours in school per day and making free sports and cultural/leisure activities available near their homes.

Microwave dielectric measurements and tissue characteristics of the human brain: potential in localizing intracranial tissues.

This study describes the measurements of dielectric properties in the microwave range to differentiate various human central nervous structures. Using a vector network analyser transmission and reflection coefficients were measured from 500 MHz to 18 GHz in four human formalin fixed human brains. The positions of the electrodes were marked, and the tissue was histologically stained to visualize the myelo- and the cytoarchitecture as well as the nerve fibre orientation at the electrodes. The profiles of the transmission coefficients showed a characteristic minimum peak. In order to describe this peak, a mathematical function was fitted. Parameters derived from digital image processing were used to characterize the myelo- and cytoarchitecure of the tissue at the electrodes. A multiple regression model, with the frequency at the transmission peak minimum as a dependent variable and two tissue characteristics at the two electrodes as independent variables, showed a multiple regression coefficient of 0.765. A neural network model was able to estimate the frequency at the transmission peak minimum from the tissue characteristics at the electrode. The measurements of dielectric properties are well suited to differentiate distinct intracerebral structures. The method could be used for online monitoring of the needle's position during a stereotactic intervention in neurosurgery.