Spatial and temporal occurrence of N-nitrosamines in seven drinking water supply systems.

The spatiotemporal presence of eight N-nitrosamines in the water of seven supply systems in Quebec considered to be susceptible to these emerging disinfection by-products was evaluated. This is the first study on the presence of N-nitrosamines in drinking water utilities in Quebec. Seven sampling campaigns were carried out at several sampling points in each of the systems over a period of 1 year.

Joint visual attention and social triangular engagement at 3 and 6 months.

Two experiments document infants' ability to detect breaks of contact in an ongoing dyadic interaction and to use the joint attention mechanism for social triangular communication purposes. In Experiment 1, the ability of 3- and 6-month-olds to show joint attention when an adult turned to face another person in sight, and to react when both adults conversed in a reciprocal manner, was measured. In Experiment 2, 3-month-olds were tested in two joint attention conditions: a Person-Person-Object condition (PPO) and a Person-Person-Person condition (PPP).