Sir Francis Younghusband, K. C. S. I., K. C. I. E

C~i~~h. Et K I Kl

We give an algorithm fr the Computation of K-terminal reliability in planar graphs, whose worst-case complexity is strictly exponential in the square root of the total number of

48 S C I E N T I F I C a M E R I C a N

S C I E N C E Optical Pumping

The term optical pumping refers to the redistribution of atoms among their fineor hyperfine-structure levels by means of light. The resonance radiation of the atom is usually the radiation used. This is selected in some way, specifically by being circularly polarized, anisotropic, filtered, or amplitudemodulated. By unusually simple experimental techniques it is possible to measure the fine and...

4 @bullet S C I E N C E & P R a C T I C E P E R S P E C T I V E S — a P R I L 2 0 0 7

Modern imaging techniques enable researchers to observe drug actions and consequences as they occur and persist in the brains of abusing and addicted individuals. This article presents the five most commonly used techniques, explains how each produces images, and describes how researchers interpret them. The authors give examples of key findings illustrating how each technique has extended and ...

D E C I S I O N S a N D I N D E C I S I O N S

In 1989 jürgen habermas opined that Carl Schmitt was unlikely to have the same ‘power of contagion in the Anglo-Saxon world’ as had Nietzsche and Heidegger. Too deep and unbridgeable was the spiritual gulf that separated the disgraced éminence grise of the ascending Axis power—publicly, at least, a virtual taboo figure within the Federal Republic—from the more liberal climes and political sensi...