Response to Comment on "Late Upper Paleolithic occupation at Cooper's Ferry, Idaho, USA, ~16,000 years ago".

Manning builds an inappropriate Bayesian age model to assert that the initial occupation at Cooper's Ferry began only ~15,935 ± 75 to 15,130 ± 20 cal yr B.P., suggesting that our estimation of ~16,560 to 15,280 cal yr B.P. is unsupported. However, this analysis both ignores evidence of human occupation from the earliest undated cultural deposits and reflects a misapplication of Bayesian age-modeling techniques. Consequently, his results are unreliable.

Studies of collagen in bone and dentin matrix of a Columbian mammoth (late Pleistocene) of central Utah.

A Columbian mammoth, Mammuthus columbi, was excavated at an elevation of 9000 feet in Huntington Canyon, Emery County, Utah. Radiocarbon dates on the skeleton indicated death approximately 11,200 years ago. The skeleton was removed from postglacial, Late Quaternary, lake sediments deposited as glacial runoff approximately 9500 years ago. The bones and teeth were especially well preserved in a saturated lake bed. After excavation the bones and teeth were preserved by controlled desiccation, without hardeners, over a period of 9 months. Microradiography, light and electron microscopy, medium and high angle X-ray diffraction, amino acid analysis and cyanogen bromide peptide mapping were undertaken to evaluate the packing, organization, and preservation of collagen in bone and dentin of this mammoth. Microradiography and light microscopy showed that the bone consisted of especially well preserved compact and trabecular bone, and electron microscopy of demineralized bone and tusk showed that the matrix consisted of lamellae of densely packed cylindrical collagen fibrils. Cell remnants with intact nuclei, with or without a nucleolus, as well as variable lengths of plasma membrane were occasionally present on the surface of bony trabecula. Remnants of odontoblast processes were present in some dentin tubules. High and low angle X-ray diffraction demonstrated that the demineralized matrix contained native collagen molecules and amino acid analysis showed that the composition was comparable to that of type I collagen. Cyanogen bromide peptide mapping indicated that the major peptides of type I collagen were present and had the same electrophoretic mobility as that of type I collagen of demineralized Asian elephant bone and rat tail tendon.(ABSTRACT TRUNCATED AT 250 WORDS)

Group discussion and drug abuse prevention.

The present study examined the usefulness of applying a group discussion technique known as the choice shift procedure to drug abuse prevention. Choice shift discussions produced both immediate and long-term antiabusive changes in college womens' drug attitudes. A second intervention, public commitment, exerted a variable influence on immediate attitude change. These results suggest that the group choice shift procedure could prove to be a useful component of drug abuse prevention programs.