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The Asymmetric Simple Exclusion Process (ASEP) is a fundamental model in non-equilibrium statistical physics. ASEP models the movement of interacting particles that hop along a chain of sites. The movement is unidirectional and satisfies a simple exclusion principle, that is, the particles can block each other, leading to “traffic jams.” ASEP has been used as a model for translation-elongation. This is a crucial biological process in which ribosomes move along the mRNA chain and decode it to produce the corresponding proteins. ASEP has also been used to model and study numerous other natural and artificial processes, ranging from vehicles moving along a highway to data packets sent along a serial chain of buffers. The Ribosome Flow Model (RFM) is a deterministic ODE model derived via a mean-field approximation of ASEP. In this talk, we describe the analysis of the RFM using tools from systems and control theory. We prove that the dynamics converges to a unique steady-state; entrains to periodic transition rates; and that the steady-state output (or protein production) rate is a concave function of the model parameters. We present several biological implications of the analysis and compare them to known experimental results. Joint work with Tamir Tuller (Tel Aviv University) and Eduardo D. Sontag (Rutgers University).

Atomic and Molecular Data Unit, Nuclear Data Section, IAEA, P.O. Box 100, A-1400, Vienna, Austria

In recent years, new regimes of matter have been created with large plasma generation devices, such as NIF (National Ignition Facility), high power short pulse lasers, X-ray free electron lasers (XFEL) and Z machines. New states of matter have been created over a wide range of plasma conditions: hotter and denser, highly transient, warm dense, or astronomically high x-ray photoionized plasmas. The new state of matter requires new theories and modelling capabilities. In terms of diagnostics, plasma spectroscopy has been applied to understand the new states of matter.

To address the issues in plasma spectroscopy of the new state of plasmas, a generalized model of atomic processes in plasmas, FLYCHK, has been developed over a decade to provide experimentalists fast and simple but reasonable predictions of atomic properties of plasmas. For a given plasma condition, it provides charge state distributions and spectroscopic properties, which have been extensively used for experimental design and data analysis. It has been applied to a wide range of plasma conditions relevant to long or short-pulse laser-produced plasmas, tokamak plasmas, or astrophysical plasmas. The FLYCHK code is currently available through NIST web site (http://nlte.nist.gov/FLY) for more than 600 users.

An overview of new machines used by high energy density physics will be given, and the FLYCHK code descriptions and applications are presented.
Briefly, IAEA activities on atomic, molecular and plasma-surface interaction data for fusion and other applications will be presented.