Preception in the rat: Autonomic response to shock as a function of length of the warning interval.

The autonomic response (galvanic skin response) to a noxious stimulus (shock) is reduced when the stimulus is preceded by a warning signal. The greatest reduction, 53%, was obtaqined with a warning interval of 1 second. Warning also reduces variance of the response over trials, a decrease of over 90% for the optimum 1-second interval

Social Mobility in Latin America: Links with Adolescent Schooling

This paper proposes a new measure of social mobility. It is based on schooling gap regressions and uses the Fields decomposition to determine the importance of family background in explaining teenagers schooling gaps.

Social Mobility in Bolivia is Finally Improving!

This paper evaluates the degree of social mobility in Bolivia, both by comparing to other Latin American countries, and by comparing social mobility at different points in time. While Bolivia had one of the lowest levels of social mobility in the region in 1997, the last 10 years have seen spectacular improvements, especially for rural and female teenagers. This is very good news, as it suggests that Bolivia has finally escaped the low mobility – low growth equilibrium where it has been stuck for so long.Social Mobility, Bolivia

How Best to Use the Extraordinary Hydrocarbon Revenues in Bolivia: Results from a Computable General Equilibrium Model

The high oil prices and the sharp increases in royalties mean that the natural gas boom in Bolivia has become very important for the economy, and particularly important as a source of government revenues. Using a CGE model, Andersen et al (2006) show that the natural gas boom is likely to boost GDP growth by about 1 percentage point per year. However, if the government continues with past spending and investment patterns, the boom is also likely to have a very adverse effect on the income distribution, so much so that the poorest half of the population is likely to experience absolute reductions in their real income levels compared to a scenario without gas boom. The present paper explores alternative uses of natural gas revenues in the CGE model to see if a better outcome can be engineered.Natural Gas, Inequality, CGE model, Bolivia

Operator content of the critical Potts model in d dimensions and logarithmic correlations

Using the symmetric group $S_Q$ symmetry of the $Q$-state Potts model, we classify the (scalar) operator content of its underlying field theory in arbitrary dimension. In addition to the usual identity, energy and magnetization operators, we find fields that generalize the $N$-cluster operators well-known in two dimensions, together with their subleading counterparts. We give the explicit form of all these operators -- up to non-universal constants -- both on the lattice and in the continuum limit for the Landau theory. We compute exactly their two- and three-point correlation functions on an arbitrary graph in terms of simple probabilities, and give the general form of these correlation functions in the continuum limit at the critical point. Specializing to integer values of the parameter $Q$, we argue that the analytic continuation of the $S_Q$ symmetry yields logarithmic correlations at the critical point in arbitrary dimension, thus implying a mixing of some scaling fields by the scale transformation generator. All these logarithmic correlation functions are given a clear geometrical meaning, which can be checked in numerical simulations. Several physical examples are discussed, including bond percolation, spanning trees and forests, resistor networks and the Ising model. We also briefly address the generalization of our approach to the $O(n)$ model.Comment: 35 pages, 6 figure

The semiflexible fully-packed loop model and interacting rhombus tilings

Motivated by a recent adsorption experiment [M.O. Blunt et al., Science 322, 1077 (2008)], we study tilings of the plane with three different types of rhombi. An interaction disfavors pairs of adjacent rhombi of the same type. This is shown to be a special case of a model of fully-packed loops with interactions between monomers at distance two along a loop. We solve the latter model using Coulomb gas techniques and show that its critical exponents vary continuously with the interaction strenght. At low temperature it undergoes a Kosterlitz-Thouless transition to an ordered phase, which is predicted from numerics to occur at a temperature T \sim 110K in the experiments.Comment: 4 pages, 4 figures, v2: corrected typo, v3: minor modifications, published versio