Bioaccumulation and ecotoxicity of carbon nanotubes

Carbon nanotubes (CNT) have numerous industrial applications and may be released to the environment. In the aquatic environment, pristine or functionalized CNT have different dispersion behavior, potentially leading to different risks of exposure along the water column. Data included in this review indicate that CNT do not cross biological barriers readily. When internalized, only a minimal fraction of CNT translocate into organism body compartments. The reported CNT toxicity depends on exposure conditions, model organism, CNT-type, dispersion state and concentration. In the ecotoxicological tests, the aquatic organisms were generally found to be more sensitive than terrestrial organisms. Invertebrates were more sensitive than vertebrates. Single-walled CNT were found to be more toxic than double-/multi-walled CNT. Generally, the effect concentrations documented in literature were above current modeled average environmental concentrations. Measurement data are needed for estimation of environmental no-effect concentrations. Future studies with benchmark materials are needed to generate comparable results. Studies have to include better characterization of the starting materials, of the dispersions and of the biological fate, to obtain better knowledge of the exposure/effect relationships

Sleep and temperament in early childhood

Sleep and temperament represent key behaviours in early childhood that reflect underlying individual constitutional differences and influence each other, and many developmental processes over time. This chapter aims to provide the reader with a basic understanding of the early childhood temperament field including definitions, history, and measurement issues. An overview of the key findings in regards to early sleep behaviours and temperament interactions across the first five years of life is provided, and the important role of the parenting environment is briefly explained. While there remain a number of challenges to overcome in the field, two key areas are further developed here. Future work should aim to increase our understanding about why early sleep and temperament are linked, and about the mechanisms involved in transactional developmental systems involving sleep, temperament, genes, and the parenting environment. Multi-disciplinary and creative modelling approaches will be needed to advance the field which should seek to create translatable research findings for the early childhood health and education sectors. Research should contribute to identifying children at the highest risk of ongoing sleep and social-emotional adjustment problems, and address these with appropriately targeted prevention and intervention strategies that support parents, educators, and health practitioners in their roles