Bayesian Local Extremum Splines.

We consider shape restricted nonparametric regression on a closed set [Formula: see text], where it is reasonable to assume the function has no more than H local extrema interior to [Formula: see text]. Following a Bayesian approach we develop a nonparametric prior over a novel class of local extremum splines. This approach is shown to be consistent when modeling any continuously differentiable function within the class considered, and is used to develop methods for testing hypotheses on the shape of the curve. Sampling algorithms are developed, and the method is applied in simulation studies and data examples where the shape of the curve is of interest.

Historical Context and Recent Advances in Exposure-Response Estimation for Deriving Occupational Exposure Limits.

Virtually no occupational exposure standards specify the level of risk for the prescribed exposure, and most occupational exposure limits are not based on quantitative risk assessment (QRA) at all. Wider use of QRA could improve understanding of occupational risks while increasing focus on identifying exposure concentrations conferring acceptably low levels of risk to workers. Exposure-response modeling between a defined hazard and the biological response of interest is necessary to provide a quantitative foundation for risk-based occupational exposure limits; and there has been considerable work devoted to establishing reliable methods quantifying the exposure-response relationship including methods of extrapolation below the observed responses. We review several exposure-response modeling methods available for QRA, and demonstrate their utility with simulated data sets.

Effects of the evisceration and cooling processes on the incidence of Salmonella in fresh dressed turkeys grown under Salmonella-controlled and uncontrolled environments.

In July and December 1981, turkeys grown in a Salmonella-free environment were sampled at the end of the slaughter and evisceration processes to determine the effect of slaughter and evisceration on the incidence of Salmonella in raw, eviscerated turkeys. A total of 109 eviscerated turkeys from the Salmonella-free flocks and 79 control turkeys were sampled. A total of 75 environmental swab samples and 5 chiller water samples were collected. Less than 1% of the eviscerated Salmonella-free turkeys were Salmonella positive and 6.3% of the eviscerated control turkeys were Salmonella positive. The results of the swab samples indicated generally good processing equipment sanitation.