Theory of amorphous ices

We derive a phase diagram for amorphous solids and liquid supercooled water and explain why the amorphous solids of water exist in several different forms. Application of large-deviation theory allows us to prepare such phases in computer simulations. Along with nonequilibrium transitions between the ergodic liquid and two distinct amorphous solids, we establish coexistence between these two amorphous solids. The phase diagram we predict includes a nonequilibrium triple point where two amorphous phases and the liquid coexist. While the amorphous solids are long-lived and slowly-aging glasses, their melting can lead quickly to the formation of crystalline ice. Further, melting of the higher density amorphous solid at low pressures takes place in steps, transitioning to the lower density glass before accessing a nonequilibrium liquid from which ice coarsens.Comment: revision following review comment

Research with twins: The concept of emergenesis.

Preliminaty findings from an on-going study of monozygotic twins reared apart (MZA) and data from a larger sample of twins reared together (MZT and DZT), indicate a surprisingly strong influence of genetic variation on aptitudes, psychophysiological characteristics, personality traits and even dimensions of attitude and interest. For some of these variables, MZT and MZA twins show high intra-class correlations while DZT twins are no more similar than pairs of unrelated persons. It is suggested that such traits are “emergenic,” i.e., that they are determined by the interaction--rather than the sum--of genetic influences. Emergenic traits, although perhaps strongly genetic, will not tend to run in families and for this reason have been neglected by students of behavior genetics. For this and several other listed reasons, wider use of twins in psychological research is strongly recommended

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

Explicit concave fillings of contact three-manifolds

In this paper we give explicit, handle-by-handle constructions of concave symplectic fillings of all closed, oriented contact 3-manifolds. These constructions combine recent results of Giroux relating contact structures and open book decompositions of 3-manifolds, earlier results of the author on attaching 4-dimensional symplectic 2-handles along transverse links, and some tricks with mapping class groups of compact surfaces with non-empty boundary.Comment: 15 pages. Accepted for publication in the Mathematical Proceedings of the Cambridge Philosophical Society. Current version is identical to final version submitted to the journal, differs from original version only in some notation and minor editorial change