Visible absorption spectra of particulate and dissolved materials were characterized on the continental shelf off the southeastern United States (the South Atlantic Bight), emphasizing cross-shelf and seasonal variability. A coastal front separates turbid coastal waters from clearer midshelf waters. Spatial and seasonal patterns were evident in absorption coefficients for phytoplankton, detritus, and colored dissolved organic matter (CDOM); spectral shape parameters for CDOM and detritus; and phytoplankton chlorophyll-specific absorption. The magnitude of CDOM absorption reflected seasonal differences in freshwater discharge and the salinity of the midshelf waters. In the spring of 1993 (high discharge), CDOM absorption at 443 nm was >10 times that of total particulate absorption between 12 and 50 km offshore (0.28-0.69 m -1 versus 0.027-0.062 m -1) and up to 10 times the CDOM absorption measured in the previous summer (low discharge). Phytoplankton chlorophyll-specific absorption in the blue increased with distance from shore (from <0.03 m 2 mg -• in inner shelf waters to -0.1 m 2 mg -1 at the most seaward stations in summer) and, for similar chlorophyll concentrations, was higher in summer than in the winter-spring. These spatial and seasonal patterns in phytoplankton chlorophyll-specific absorption can be attributed to a shift in phytoplankton species composition (from predominantly diatoms inshore to a cyanobacteria-dominated assemblage midshelf in summer), pigment packaging, and higher carotenoid:chlorophyll with distance from shore.

Findings demonstrate that a majority of parents accepted newborn screening for FMR1 gene expansions, but decision rates and reasons for accepting or declining varied in part as a function of race/ethnicity and in part as a function of what parents most valued or feared in their assessment of risks and benefits.

The project documented public acceptance of screening as well as the challenges inherent in obtaining consent in the hospital shortly after birth. Collectively, the study provides answers to a number of questions that now set the stage for a next generation of research to determine the benefits of earlier identification for children and families.

1. The relationship between toxicant-induced changes in the feeding behaviour of the eladoceran, Daphnia catawba (Coker), and subsequent effects at population and community levels were experimentally addressed.2. We adapted a method for measuring the thoracic appendage beat rate of individuals (termed the TAR and positively correlated with daphnid feeding rate) after exposure to toxicant at known levels, for use as a behavioural bioassay for low levels of aquatic toxicants. The TAR declined significantly with an increase in both sublethal and lethal levels of the surfactant, sodium dodecyl sulphate (SDS).3. We also measured population level effects (i.e. rates of reproduction, survival, and fio), and found that reductions in these values occurred at the same concentrations as the effects on individual behaviour. 4. In most cases, the changes in feeding behaviour occurred more rapidly (< 30 h) than changes in population parameters (days to weeks). 5. We conclude that toxicant-induced changes in individual feeding behaviour can provide a quicker estimate of effects on individuals and of potential community effects (i.e. effects on their prey populations) than measurements of population parameters. In addition, due to its sensitivity at low levels of toxicants, the behavioural bioassay may be particularly helpful in identifying effects of sublethal levels of aquatic pollutants.

In a large-scale population-based study, 19.6% of fathers were absent for the consent process. Scenarios encountered underscore the complexity of parental relations and their implications for obtaining consent for research involving children. The algorithm developed may serve as a useful tool for others in applying the regulatory requirements for dual parental permission.