The use of SEM/EDS analysis to distinguish dental and osseus tissue from other materials

With increasing frequency, relatively small, fragmentary evidence thought to be osseous or dental tissue of human origin is submitted to the forensic laboratory for DNA analysis with the request for positive identification. Prior to performing DNA analysis, however, it is prudent to first perform a presumptive test or "screen" to determine whether the questioned material may be eliminated from further consideration. When material is shown not to be consistent with bone/teeth, DNA testing is not performed. When such determinations cannot be made from gross morphological features, elemental analysis can be indicative. This presumptive test is made possible by applying scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS) in conjunction with an X-ray spectral database recently developed by the FBI laboratory. This database includes spectra for many different materials including known examples of bone and tooth from many different contexts and representing the full range of taphonomic conditions. Results of SEM/EDS analysis of evidence can be compared to these standards to determine if they are consistent with bone and/or tooth and, if not, then what the material might represent. Analysis suggests that although the proportions and amounts of calcium and phosphorus are particularly important in differentiating bone and tooth from other materials, other minor differences in spectral profile can also provide significant discrimination. Analysis enables bone and tooth to be successfully distinguished from other materials in most cases. Exceptions appear to be ivory, mineral apatite, and perhaps some types of corals.     

The effectiveness of regulatory disclosure policies

Regulatory transparency—mandatory disclosure of information by private or public institutions with a regulatory intent—has become an important frontier of government innovation. This paper assesses the effectiveness of such transparency systems by examining the design and impact of financial disclosure, nutritional labeling, workplace hazard communication, and five other diverse systems in the United States. We argue that transparency policies are effective only when the information they produce becomes “embedded” in the everyday decision‐making routines of information users and information disclosers. This double‐sided embeddedness is the most important condition for transparency systems' effectiveness. Based on detailed case analyses, we evaluate the user and discloser embeddedness of the eight major transparency policies. We then draw on a comprehensive inventory of prior studies of regulatory effectiveness to assess whether predictions about effectiveness based on characteristics of embeddedness are consistent with those evaluations. © 2006 by the Association for Public Policy Analysis and Management