An overview of regulatory issues that affect the development of new waste treatment technologies

The development of new and innovative waste treatment technologies can significantly benefit the U.S. Department of Energy's (DOE) environmental restoration and waste management program. New technologies are expected to facilitate faster, better, cheaper, and safer remediation of existing waste problems. To encourage and direct the development of new waste treatment and management technologies, DOE established a research, development, demonstration, testing, and evaluation (RDDT E) program. The RDDT E program is managed by DOE's Office of Technology Development. The development, acceptance, and application of new technologies involves more than simply technical problems. If the best new technologies are to be applied in the fastest and most cost-effective manner possible, DOE must consider regulatory factors early and often in the technology development process. This report presents a number of regulatory issues that are relevant to any program intended to encourage the development of new waste treatment and management technologies. The report was prepared by Pacific Northwest Laboratory. 38 refs., 6 figs., 2 tabs

The Biochemistry, Ultrastructure, and Subunit Assembly Mechanism of AMPA Receptors

The AMPA-type ionotropic glutamate receptors (AMPA-Rs) are tetrameric ligand-gated ion channels that play crucial roles in synaptic transmission and plasticity. Our knowledge about the ultrastructure and subunit assembly mechanisms of intact AMPA-Rs was very limited. However, the new studies using single particle EM and X-ray crystallography are revealing important insights. For example, the tetrameric crystal structure of the GluA2cryst construct provided the atomic view of the intact receptor. In addition, the single particle EM structures of the subunit assembly intermediates revealed the conformational requirement for the dimer-to-tetramer transition during the maturation of AMPA-Rs. These new data in the field provide new models and interpretations. In the brain, the native AMPA-R complexes contain auxiliary subunits that influence subunit assembly, gating, and trafficking of the AMPA-Rs. Understanding the mechanisms of the auxiliary subunits will become increasingly important to precisely describe the function of AMPA-Rs in the brain. The AMPA-R proteomics studies continuously reveal a previously unexpected degree of molecular heterogeneity of the complex. Because the AMPA-Rs are important drug targets for treating various neurological and psychiatric diseases, it is likely that these new native complexes will require detailed mechanistic analysis in the future. The current ultrastructural data on the receptors and the receptor-expressing stable cell lines that were developed during the course of these studies are useful resources for high throughput drug screening and further drug designing. Moreover, we are getting closer to understanding the precise mechanisms of AMPA-R-mediated synaptic plasticity