51 research outputs found
Fresnel laws at curved dielectric interfaces of microresonators
We discuss curvature corrections to Fresnel's laws for the reflection and
transmission of light at a non-planar refractive-index boundary. The reflection
coefficients are obtained from the resonances of a dielectric disk within a
sequential-reflection model. The Goos-H\"anchen effect for curved light fronts
at a planar interface can be adapted to provide a qualitative and quantitative
extension of the ray model which explains the observed deviations from
Fresnel's laws.Comment: submitted to Phys. Rev.
Reevaluation of the role of nuclear uncertainties in experiments on atomic parity violation with isotopic chains
In light of new data on neutron distributions from experiments with
antiprotonic atoms [ Trzcinska {\it et al.}, Phys. Rev. Lett. 87, 082501
(2001)], we reexamine the role of nuclear-structure uncertainties in the
interpretation of measurements of parity violation in atoms using chains of
isotopes of the same element. With these new nuclear data, we find an
improvement in the sensitivity of isotopic chain measurements to ``new
physics'' beyond the standard model. We compare possible constraints on ``new
physics'' with the most accurate to date single-isotope probe of parity
violation in the Cs atom. We conclude that presently isotopic chain experiments
employing atoms with nuclear charges Z < 50 may result in more accurate tests
of the weak interaction.Comment: 6 pages, 1 fig., submitted to Phys. Rev.
Visual Network Analysis of Dynamic Metabolic Pathways
Abstract. We extend our previous work on the exploration of static metabolic
networks to evolving, and therefore dynamic, pathways. We apply our visualization software to data from a simulation of early metabolism. Thereby, we show
that our technique allows us to test and argue for or against different scenarios for
the evolution of metabolic pathways. This supports a profound and efïŹcient analysis of the structure and properties of the generated metabolic networks and its
underlying components, while giving the user a vivid impression of the dynamics
of the system. The analysis process is inspired by Ben Shneidermanâs mantra of
information visualization. For the overview, user-deïŹned diagrams give insight
into topological changes of the graph as well as changes in the attribute set associated with the participating enzymes, substances and reactions. This way, âinteresting featuresâ in time as well as in space can be recognized. A linked view
implementation enables the navigation into more detailed layers of perspective
for in-depth analysis of individual network conïŹguration
Simulating Evolutionâs First Steps
Abstract. We demonstrate a simple artificial chemistry environment in which two small evolutionary transitions from the simplest self-replicators to larger ones are observed. The replicators adapt to increasingly harsh environments, where they must synthesise the components they need for replication. The evolution of a biosynthetic pathway of increasing length is thus achieved, through the use of simple chemical rules for catalytic action.
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