Tough sell

Solar system exploration. Technology is essential, but it's a tough sell.

ogy is no match for Mercury’s broiling temperatures or Jupiter’s deadly magnetic field. But planetary scientists face the daunting prospect of planning 21st century explorations of more hostile regions of the solar system for longer periods with technology largely unchanged since the 1970s heyday of Voyager and Viking. When it comes to speed, power, and communications systems, says NASA space s...

Making a Tough Sell: Options for Promoting Energy Efficiency in New California Homes

This product is part of the RAND Science and Technology working paper series. RAND working papers are intended to share researchers' latest findings and to solicit informal peer review. They have been approved for circulation by RAND Science and Technology but have not been formally edited or peer reviewed. Unless otherwise indicated, working papers can be quoted and cited without permission of...

Tough times call for tough decisions.

Tough spiders

Spider graphs are the intersection graphs of subtrees of subdivisions of stars. Thus, spider graphs are chordal graphs that form a common superclass of interval and split graphs. Motivated by previous results on the existence of Hamilton cycles in interval, split and chordal graphs, we show that every 3/2-tough spider graph is hamiltonian. The obtained bound is best possible since there are (3/...

Tough Mining

Caenorhabditis elegans, a 1-mm soil-dwelling roundworm with 959 cells, may be the best-understood multicellular organism on the planet. As the most " pared-down'' animal that shares essential features of human biology—from embryogenesis to aging—C. elegans is a favorite subject for studying how genes control these processes. The way these genes work in worms helps scientists understand how dise...