Learn More
A class of permutations Π is called closed if π ⊂ σ ∈ Π implies π ∈ Π, where the relation ⊂ is the natural containment of permutations. Let Π n be the set of all permutations of 1, 2,. .. , n belonging to Π. We investigate the counting functions n → |Π n | of closed classes. Our main result says that if |Π n | < 2 n−1 for at least one n ≥ 1, then there is a(More)
OBJECTIVE S100A12 is a pro-inflammatory protein that is secreted by granulocytes. S100A12 serum levels increase during inflammatory bowel disease (IBD). We performed the first study analysing faecal S100A12 in adults with signs of intestinal inflammation. METHODS Faecal S100A12 was determined by ELISA in faecal specimens of 171 consecutive patients and 24(More)
We show that the conjectures by Matthews and Sumner (every 4-connected claw-free graph is hamiltonian), by Thomassen (every 4-connected line graph is hamiltonian) and by Fleischner (every cyclically 4-edge-connected cubic graph has either a 3-edge-coloring or a dominating cycle), which are known to be equivalent, are equivalent with the statement that every(More)