A 0-1 matrix has the consecutive-ones property if its columns can be ordered so that the ones in every row are consecutive. It has the circular-ones property if its columns can be ordered so that, in every row, either the ones or the zeros are consecutive. PQ trees are used for representing all consecutive-ones orderings of the columns of a matrix that has the consecutive-ones property. We give...

A major goal of the 2006 NIEHS Strategic Plan encompasses the institute's desire to " recruit and train the next generation of environmental health scientists. " To begin to achieve that goal, the NIEHS has unveiled a new annual grants program called the Outstanding New Environmental Scientist (ONES) Award. The five-year grants are designed to identify, encourage, inspire, and support outstandi...

Many public goods are supported with both private and public funding. It is often argued that public funding, based on taxes, crowds out private philanthropic contributions. Agents respond to increases in taxes by decreasing their donations. However, the tax level depends on the political equilibrium arising from agents’ voting decisions. In this paper we analyze a variety of motivations for vo...

This talk describes a clean and unified way to enumerate all juxtaposition classes of the form “Av(abc) next to Av(xy)”, where abc is a permutation of length three and xy is a permutation of length two. The main tools are Dyck paths, decorated by sequences of points, and context free grammars, used afterwards to enumerate these decorated Dyck paths. Juxtapositions are a simple special case of p...

First-principles computations have been preformed to investigate the stability of one-dimensional (1D) crystalline nanowires, faceted nanotubes, and conventional single-walled nanotubes (SWNTs) with various sizes, as well as the two-dimensional infinitely single layers for several wurtzite materials. Regardless of the diameters, the SWNTs are more stable than sp(3)-dominated faceted nanotubes a...

We show by means of a counterexample that a C diffeomorphism Hölder conjugate to an Anosov diffeomorphism is not necessarily Anosov. The counterexample can bear higher smoothness up to C. Also we include a result from the 2006 Ph.D. thesis of T. Fisher: a C diffeomorphism Hölder conjugate to an Anosov diffeomorphism is Anosov itself provided that Hölder exponents of the conjugacy and its invers...

To improve the diversity of the scientific workforce, we should not penalize researchers who are unable to move abroad for long periods.

An overview of research on the implementation of neural systems is presented in this paper. We focus on implementations where the algorithms and their physical support are tightly coupled. First, we concentrate on the potential of probabilistic algorithms to compensate for hardware non-idealities. Then, electronic circuits which aim to reproduce the structure of neurobiological systems in hardw...

Enhancing thermal conductivity of simple fluids is of major interest in numerous applicative systems. One possibility of enhancing thermal properties consists of dispersing small conductive particles inside. However, in general, aggregation effects occur and then one must address systems composed of dispersed clusters composed of particles as well as the ones related to percolated networks. Thi...