Mercury Ion Clock for a NASA Technology Demonstration Mission.

There are many different atomic frequency standard technologies but only few meet the demanding performance, reliability, size, mass, and power constraints required for space operation. The Jet Propulsion Laboratory is developing a linear ion-trap-based mercury ion clock, referred to as DSAC (Deep-Space Atomic Clock) under NASA's Technology Demonstration Mission program. This clock is expected to provide a new capability with broad application to space-based navigation and science.

The natural history of intravascular lymphomatosis.

Intravascular lymphomatosis (IVL) is a rare and clinically devastating form of extranodal B-cell non-Hodgkin's lymphoma. We performed a comprehensive analysis of the literature on IVL's published between 1959 and 2011 and evaluated the natural history as well as identified prognostic and predictive factors in patients. Nonparametric two-tailed Mann-Whitney U-test and Mantel-Cox log rank test were used to evaluate the survival intervals and prognostic factors.