How the Liquid-Liquid Transition Affects Hydrophobic Hydration in Deeply Supercooled Water

We determine the phase diagram of liquid supercooled water by extensive computer simulations using the TIP5P-E model [J. Chem. Phys. {\bf 120}, 6085 (2004)]. We find that the transformation of water into a low density liquid in the supercooled range strongly enhances the solubility of hydrophobic particles. The transformation of water into a tetrahedrally structured liquid is accompanied by a minimum in the hydration entropy and enthalpy. The corresponding change in sign of the solvation heat capacity indicates a loss of one characteristic signature of hydrophobic hydration. The observed behavior is found to be qualitatively in accordance with the predictions of the information theory model of Garde et al. [Phys. Rev. Lett. {\bf 77}, 4966 (1996)].Comment: 4 pages, 4 figures, twocolumn Revtex, modified text applied changes to figure 1, 2d, 3,

The effect of expected income on individual migration decisions

economic models;migration;decision making;income distribution

Plio-Quaternary sediment budget between thrust belt erosion and foreland deposition in the central Andes, southern Bolivia

Estimates of the physical boundary conditions on sediment source and sink regions and the flux between them provide insights into the evolution of topography and associated sedimentary basins. We present a regional-scale, Plio-Quaternary to recent sediment budget analysis of the Grande, Parapeti and Pilcomayo drainages of the central Andean fold-thrust belt and related deposits in the Chaco foreland of southern Bolivia (18–23°S). We constrain source-sink dimensions, fluxes and their errors with topographic maps, satellite imagery, a hydrologically conditioned digital elevation model, reconstructions of the San Juan del Oro (SJDO) erosion surface, foreland sediment isopachs and estimated denudation rates. Modern drainages range from 7453 to 86 798 km 2 for a total source area of 153 632 km 2 . Palaeo-drainage areas range from 9336 to 52 620 km 2 and total 100 706 km 2 , suggesting basin source area growth of ∼50% since ∼10 Ma. About 2.4–3.1 × 10 4  km 3 were excavated from below the SJDO surface since ∼3 Ma. The modern foredeep is 132 080 km 2 with fluvial megafan areas and volumes ranging from 6142 to 22 511 km 2 and from 1511 to 3332 km 3 , respectively. Since EmborozÚ Formation deposition beginning 2.1 ± 0.2 Ma, the foreland has a fill of ∼6.4 × 10 4  km 3 . The volume and rate of deposition require that at least ∼40–60% of additional sediment be supplied beyond that incised from below the SJDO. The data also place a lower limit of ≥0.2 mm year −1 (perhaps ≥0.4 mm year −1 ) on the time- and space-averaged source area denudation rate since ∼2–3 Ma. These rates are within the median range measured for the Neogene, but are up to 2 orders of magnitude higher than some observations, as well as analytic solutions for basin topography and stratigraphy using a two-dimensional mathematical model of foreland basin evolution. Source-to-sink sediment budget analyses and associated interpretations must explicitly and quantitatively reconcile all available area, volume and rate observations because of their inherent imprecision and the potential for magnification when they are convolved.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73668/1/j.1365-2117.2008.00372.x.pd

The Effect of Expected Income on Individual Migration Decisions

The paper develops a tractable econometric model of optimal migration, focusing on expected income as the main economic influence on migration. The model improves on previous work in two respects: it covers optimal sequences of location decisions (rather than a single once-for-all choice), and it allows for many alternative location choices. The model is estimated using panel data from the NLSY on white males with a high school education. Our main conclusion is that interstate migration decisions are influenced to a substantial extent by income prospects. The results suggest that the link between income and migration decisions is driven both by geographic differences in mean wages and by a tendency to move in search of a better locational match when the income realization in the current location is unfavorable.

A Galactic Bar to Beyond the Solar Circle and its Relevance for Microlensing

The Galactic kinematics of Mira variables have been studied using infrared photometry, radial velocities, and Hipparcos parallaxes and proper motions. For Miras in the period range 145 to 200 days (probably corresponding to [Fe/H] in the range -0.8 to -1.3) the major axes of the stellar orbits are concentrated in the first quadrant of Galactic longitude. This is interpreted as a continuation of the bar-like structure of the Galactic Bulge out to the solar circle and beyond.Comment: 6 pages, 2 figures. To be published in: Microlensing 2000. ASP Conference Series, Eds. J W Menzies, P Sacket

Strategic Union Delegation and Strike Activity

We develop a model of wage determination with private information, in which te union has the option to delegate the wage bargaining to either surplus-maximizing delegates or to wage-maximizing delegates (such as senior union members). We show that the strike activity is greater whenever the union chooses wage-maximizing delegates instead of surplus-maximizing delegates. We also provide the necessary and sufficient condition such that it is always optimal for the union to choose wage-maximizing delegates and we we find that the efficiency loss due to strategic delegation may be quite important.Union delegation;Wage bargaining;Private information;Strike activity

Faculty Recital Series: The Art of the Sonata, Part III, October 6, 2011

This is the concert program of the Faculty Recital Series: The Art of the Sonata, Part III performance on Thursday, October 6, 2011 at 8:00 p.m., at the Tsai Performance Center, 685 Commonwealth Avenue, Boston, Massachusetts. Works performed were Sonata by Harold Shapero, Sonata by George Antheil, Sonata by Halsey Stevens, and Sonata by Kent Kennan. Digitization for Boston University Concert Programs was supported by the Boston University Humanities Library Endowed Fund