Exordium for DNA Codes

We describe how deletion-correcting codes may be enhanced to yield codes with double-strand DNA-sequence codewords. This enhancement involves abstractions of the pertinent aspects of DNA; it nevertheless ensures specificity of binding for all pairs of single strands derived from its codewords-the key desideratum of DNA codes- i.e. with binding feasible only between reverse complementary strands. We defer discussing the combinatorial-optimization superincumbencies of code construction. Generalization of deletion similarity to an optimal sequence-alignment score could readily effect advantageous improvements (Kaderali, Master's Thesis, Informatics, U. Köln, 2001) but would render the combinatorics opaque. We mention motivating applications of DNA codes

Clusters of charged diamagnetic particles levitating in nonuniform magnetic field

For confinement and investigation of strongly coupled systems of charged macroparticles, we propose to use a trap based on the known possibility of the levitation of diamagnetic bodies in a nonuniform steady-state magnetic field. An experimental setup is described, which is capable of forming and confining clusters of charge graphite particles sized 100 to 300 μm in magnetic field B ~ 1 T and $|\nabla B|$ ~  10 T/cm. It is inferred that it will be possible to form stable 3D structures containing several thousands macroparticles under terrestrial conditions by using fields B > 10 T, and under microgravity conditions by using fields B ~ 0.1 T

Dynamics of dust structures in a dc discharge under action of axial magnetic field

Results of experiments on the formation of dusty plasma structures in a stratified dc discharge in axial magnetic fields up to 2500 G are presented. The rotation of the rather small and planar dusty plasma structures has been observed. As the field increases, the inversion of the structure rotation occurs, and when it reaches 700 G, the displacement of dust particles from the axial region of the discharge to the periphery, along with the rotation continuation, is observed. The explanation of the features in the dynamical behavior of the dust particles in the discharge, in particular the rotation inversion, is proposed