The in vitro influence of the burrowing polychaete Nereis diversicolor on the fate of petroleum hydrocarbons in marine sediments

The in vitro fate of the saturated hydrocarbon fraction (SF) of Arabian Light crude oil has been studied in PVC cores filled with a coastal marine sediment defaunated by sieving. Experiments were conducted in absence or presence of polychaetes Nereis diversicolor. The luminophore tracer technique was used to quantify the mixing of sediment by worms. Presence of crude oil reduced the building of burrows by polychaetes. This work demonstrates the ability of infaunal organisms to stimulate both downard and outward transfers of hydrocarbons from sediment reservoirs. In non-bioturbated sediment hydrocarbons were confined to the sediment surface. Introduction of polychaetes in sediment (1) induced the burying of SF in sediment (2.5 % and 13.5 % of the initial surface input after 15 and 45 days, respectively); (2) enhanced the exportation of SF in the overlying water (plus 59 % and 23.5 % compared to defaunated control sediment after 15 and 45 days, respectively). Buried hydrocarbons were submitted to biodegradation, from 2 cm to 10 cm depth in polychaete burrows, after 45 days

Who uses online parenting support? A cross-sectional survey exploring Australian parents’ internet use for parenting

The need for better access to evidence-based parenting interventions is widely recognized, as few families actually participate in parenting programs. A public health approach that includes the delivery of parenting information via the Internet could increase the reach of such interventions dramatically. However, there are concerns that web-based information is not accessible by families that face the greatest barriers to accessing “traditional” face-to-face parenting support, and therefore could benefit most from online approaches. This study used a cross-sectional survey of 459 Australian parents of 2–12 year olds to investigate parents’ use of the Internet to access parenting information, and the extent to which this information is useful for parents from a range of socio-economic backgrounds. Results indicate that the majority of parents use parenting websites (65 %) and social media (45 %) for parenting information. Users of parenting websites tended to be parents of younger children. Younger age of the child was also associated with using social media, as was younger parental age, being female, not working and spending more hours online. Parents rated a range of modalities as useful for receiving parenting information, particularly seminars and individually tailored programs. Self-directed web-based programs were endorsed by 61 % of respondents. Higher-risk parents were as likely or more likely to endorse web-based information sources as lower-risk parents. As there was almost equal access to online parenting information among families from different backgrounds, we conclude that the Internet provides an exciting opportunity for delivering evidence-based parenting support to a broad range of parents, including higher-risk families

Effect of bioturbation on denitrification in a marine sediment from the West Mediterranean littoral

The in vitro effect of Nereis diversicolor on denitrification has been studied in PVC tubes filled with a coastal marine sediment defaunated by sieving. The first aim of the experiment was to determine the effect of sediment defaunation on denitrification (denitrifying population and Denitrifying Enzyme Assays). Sieving induced a loss of 70% of the initial DEA. The number of denitrifying bacteria was 10 times lower than inin situ sediment. In the top two centimetres, the DEA rose by 75% of its initial value, after 82 days. Polychaetes were only added after a return to near pre-disturbance levels to ensure that our data on the effects of their addition would not be disturbed by changes in the sediment. Introduction of Polychaetes increased the denitrifying population and DEA in the first layer (0–2 cm) of the sediment after 15 days. After 45 days, the surface of the polychaete burrows in sediment was 1.3 to 1.5 times higher than after 15 days, resulting in an increase in solute exchange between seawater and the top layer of sediment. An inhibitory effect of oxygen on denitrification was detected in the uppermost layer only