A revolution in solid-state nuclear magnetic resonance (SSNMR) spectroscopy is taking place, attributable to the rapid development of high-field dynamic nuclear polarization (DNP), a technique yielding sensitivity improvements of 2–3 orders of magnitude. This higher sensitivity in SSNMR has already impacted materials research, and the implications of new methods on catalytic sciences are expect...

This paper examines the applications most commonly run on the supercomputers at the Numerical Aerospace Simulation (NAS) facility. It analyzes the extent to which such applications are fundamentally oriented to vector computers, and whether or not they can be e ciently implemented on hierarchical memory machines, such as systems with cache memories and highly parallel, distributed memory system...

The Ames assay has received widespread attention from statisticians because of its popularity and importance to risk assessment. However, investigators have yet to routinely apply modern regression methods that have been available for more than a decade. We study yet another approach, the application of nonparametric regression techniques, not as the ultimate solution but rather as a framework ...

Genotoxicity tests available today have several shortcomings. The widely applied Ames assay measures mutations in bacteria, thereby disregarding the physiological particularities of the human cell and organism.We provide first evidence for a new concept of genotoxicity detection in living human cell cultures. The data were obtained by use of a newly developed assay, which is based on the quanti...

While many institutions use a version of the Ames test in the undergraduate genetics laboratory, students typically are not exposed to techniques or procedures beyond qualitative analysis of phenotypic reversion, thereby seriously limiting the scope of learning. We have extended the Ames test to include both quantitative analysis of reversion frequency and molecular analysis of revertant gene s...

Modern NASA planetary exploration missions employ complex systems of hardware and sofkware managed by large teams of. engineers and scientists in order to study remote environme most complex and successful of these recent projects is the Mars Exploration Rover mission. The Computational Sciences Division at NASA Ames Research Center delivered a 3 0 visualization program, Yiz, to the MER mission...

This paper surveys recent, as yet unpublished, statistical studies arising from research in genetic toxicology within the U.S. National Toxicology Program (NTP). These studies all involve analyses of data from Ames Salmonella/microsome mutagenicity tests, but the statistical methodologies are broadly applicable. Three issues are addressed: First, what is a tenable sampling model for Ames test d...

G. J. MacDougall,1 H. M. Christen,2,* W. Siemons,2 M. D. Biegalski,3 J. L. Zarestky,4,5 S. Liang,2,6 E. Dagotto,2,6 and S. E. Nagler1,7 1Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA 2Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA 3Center for Nanophase Materials Sciences, Oak Ridge Nat...