Non-linear Coulomb blockade microscopy of a correlated one-dimensional quantum dot.

We evaluate the chemical potential of a one-dimensional quantum dot coupled to an atomic force microscope tip. The dot is described within the Luttinger liquid framework, and the conductance peak positions as a function of the tip location are calculated in the linear and non-linear transport regimes for an arbitrary number of particles. The differences between the chemical potential oscillations induced by the Friedel and Wigner terms are carefully analysed in the whole range of interaction strengths. It is shown that Friedel oscillations, unlike the Wigner ones, are sensitive probes for detecting excited spin states and collective spin density waves involved in the transport.

Preventing smoking: evaluating the potential effectiveness of cigarette warnings.

We examined the potential effectiveness of U.S. government cigarette warnings in preventing adolescent smoking. In Study 1, 112 seventh graders rated the effectiveness of four currently required warnings and four possible other warnings and answered questions about the meaning of certain words in the warnings. In Study 2, 115 seventh graders attempted to recall the four current warnings; in Study 3, 103 eighth and ninth graders read all eight warnings one day and tried to recall them the next day. In Study 4, 25 seventh graders participated in a focus session in which they discussed the effectiveness of each of the eight warnings. The results of the studies showed that the four different evaluation strategies had convergent validity and that two current warnings and two proposed warnings are significantly more potentially effective than the other two current warnings. Our results also provided information about why some warnings are more potentially effective than others.