biology

The Questions

Anti-coagulation therapy is often prescribed after surgery in order to prevent

Action potentials are the packets of communication in the nervous system. The voltage dependent sodium and potassium channels are the crucial players in the initiation and propagation of the action potential. Voltage sensing in these channels is mediated by the movement of intrinsic charges of the channel proteins in response to changes in the electric field across the cell membrane and they contribute to the non-linear capacitance of the cell membrane.

Biology occurs in concentrated mixtures of ions that are far from ideal. Solutions are remarkably concentrated where they are most important. Multi-molar solutions (often >10M) are found in and near DNA & RNA, proteins, active sites of enzymes, transporters, and ion channels, as well as electrodes of batteries. Poisson Boltzmann treatments fail dramatically to deal with the upper bound of concentration produced by the finite size of ions and so cannot describe ionic solutions of life, or ions where they are most important.

A large variety of complex systems, from the brain to the weather networks and complex infrastructures, are formed by several networks that coexist, interact and coevolve forming a network of networks. Modeling such multilayer structures and characterizing the rich interplay between their structure and their dynamical behavior is crucial in order to understand and predict complex phenomena. In this talk I will present recent works on statistical mechanics of multiplex networks. Multiplex networks are formed by N nodes linked in different layers by different networks.

Biofilms form when microbes grow attached to a surface and become encased in a self-produced extracellular matrix. The fact that biofilm growth has been observed in most bacteria studied to date suggests that this form of growth is important in the ecology and physiology of most, if not all, bacteria. Biofilms have profound impact on human health, since they can form on the surfaces of indwelling medical devices and are inherently more resistant to most antimicrobial agents, making them extremely difficult to eradicate.

Most infections are the result of a surface-attached community
of
bacteria that displays many unique characteristics. Our
understanding
is still limited, however, with respect to how pathogens are
colonizing surfaces to begin infection. It is known that the
arrival
of bacteria to host tissues is often aided by self-generated
motility
of the organism.
Pathogens such as Salmonella enterica, Vibrio cholerae, Proteus
mirabilis, and Pseudomonas aeruginosa are able to spread
rapidly over

This talk will discuss recent developments in one-electron model Hamiltonians for the hydrated electron, and their application to both anionic water clusters and bulk aqueous electrons. Our group has recently developed a new hydrated-electron model that combines the polarizable AMOEBA water model with a static exchange treatment of the electron-water interaction, parameterized from electronic structure calculations.

Joint work with Bastiaan J. Braams and Yimin Wang (Department of Chemistry and Cherry L. Emerson Center for Scientific Computation,
Emory University, Atlanta, GA 30322).

The currently exists a variety of methods to represent
potential energy surfaces for high dimensional systems, and
these will be reviewed after a short, selective, historical
introduction to the topic. I will describe the progress we have

Implicit-solvent models commonly decompose the molecular solvation free energy into a sum of electrostatic and non-polar terms, with separate theoretical and numerical procedures employed for each component. In this talk I will describe a new method for estimating the electrostatic free energy of solvation, called BIBEE (boundary-integral-based electrostatics estimation).