A group G of permutations of a set is primitive if it acts transitively on , and the only G-invariant equivalence relations on are the trivial and universal relations. A digraph is primitive if its automorphism group acts primitively on its vertex set, and is infinite if its vertex set is infinite. It has connectivity one if it is connected and there exists a vertex α of , such that the induced...

primitive neuroectodermal tumor (penets) is an uncommon malignancy of bone and soft tissue witch rarely occurs in the kidney. in more than 90% of the cases, the tumor cells relieves a balanced translocation (11; 22) (q24; q12). immunohistochemical staining may be required for diagnosis of penet. the cells of tumor express cd99, vimentin, nse, fl1 but do not express ck, lca, myogenin, and wt1. w...

We classify all primitive embeddings of the lattice numerical equivalence classes divisors an Enriques surface with intersection form multiplied by 2 into even unimodular hyperbolic rank 26. These have a property that facilitates computation automorphism group Borcherds’ method.

In this paper we find sufficient conditions on primitive inverse topological semigroup S under which: the inversion inv : (H(S)) (H(S)) is continuous; we show that every topologically periodic countable compact primitive inverse topological semigroups with closed H-classes is topologically isomorphic to an orthogonal sum P i2= Bi (Gi) of topological Brandt extensions Bi (Gi) of countably compac...

In the paper, we study finitely generated linear groups of finite rank which have faithful irreducible primitive representations over a field characteristic zero. We prove that if an infinite group [Formula: see text] has representation zero then text]-center is infinite.

A coherent algebra is F-primitive if each of its non-identity basis matrices is primitive in the sense of Frobenius. We investigate the relationship between the primitivity of a permutation group, the primitivity of its centralizer algebra, and F-primitivity. The results obtained are applied to give new proofs of primitivity criteria for the exponentiations of permutation groups and of coherent...