No abstract

A procedure has been developed for rapidly inoculating large numbers of turnip seedlings with Xanthomonas campestris pv. campestris, the causal agent of black rot of crucifers. Following mutagenesis bacterial mutants were isolated which showed altered pathogenicity. The mutants gave a range of responses on plants and some were impaired in their ability to grow in seedlings.

ABSTRACT. We investigate Bar-Natan's characteristic two Khovanov link homology theory studying both the filtered and bi-graded theories. The filtered theory is computed explicitly and the bi-graded theory analysed by setting up a family of spectral sequences. The E 2 -pages can be described in terms of groups arising from the action of a certain endomorphism on F 2 -Khovanov homology. Some simple consequences are discussed.

No abstract

We investigate link homology theories for stable equivalence classes of link diagrams on orientable surfaces. We apply .1C1/-dimensional unoriented topological quantum field theories to Bar-Natan's geometric formalism to define new theories for stable equivalence classes. 57M25, 57R56; 81T40