The Boolean ring $B$ of measurable subsets of the unit interval, modulo sets of measure zero, has proper radical ideals (for example, ${0})$ that are closed under the natural metric, but has no prime ideal closed under that metric; hence closed radical ideals are not, in general, intersections of closed prime ideals. Moreover, $B$ is known to be complete in its metric. Togethe...

If F is a vector space over an ordered division ring, C a convex subset of V and L the lattice of convex subsets of C, then we call L a convexity lattice. We give necessary and sufficient conditions for an abstract lattice to be a convexity lattice in the finite dimensional case.

We give a short, direct proof that given any finite group G there exist positive integers k and l and partitions α1 and α2 of {1, . . . , kl} into l subsets of size k such that (Skl)α1,α2 ∼= G. The method used will also show that given any finite group G there exists a regular bipartite graph whose automorphism group is isomorphic to G.

Let G := (V,E) be a simple graph; for I ⊆ V we denote by l(I) the number of components of G[I], the subgraph of G induced by I. For V1, . . . , Vn finite subsets of V , we define a function β(V1, . . . , Vn) which is expressed in terms of l `Sn i=1 Vi ́ and l(Vi ∪ Vj) for i ≤ j. If V1, . . . , Vn are pairwise disjoint finite independent subsets of V , the number β(V1, . . . , Vn) can be computed...

The tetrapeptide Acetyl-N-Ser-Asp-Lys-Pro (AcSDKP, Seraspenide; Ipsen-Biotech, Paris, France), an inhibitor of murine spleen colony-forming units reduces the number and the percentage in DNA synthesis of progenitors from human unfractionated bone marrow. To determine whether AcSDKP may directly affect the growth potential of purified progenitors even at the most primitive level, CD34+HLA-DRhigh...

The meq gene was thought to be only detected in Marek's disease virus serotype 1 (MDV 1) including a very virulent strain, Md5, while L-meq, in which a 180-bp sequence is inserted into the meq open reading frame, is found in other strains of MDV 1, such as CVI 988/R6. However, both meq and L-meq were previously detected by PCR in chickens infected with MDV 1, suggesting that MDV 1 may consists ...

Given the integers 1,, k,,1 2 , k 2 , r, which satisfy the condition 1,, 1 2 > r> k,, k 2 > 0, we define m = N(1,, k, ; 1 2 , k 2 ; r) as the smallest integer with the following property : if S is a set containing m points and the r-subsets of S are partitioned arbitrarily into two classes, then for i = 1 or 2 there exists an l i subset of S each of whose ki-subsets lies in some r-subset of the...