Let θ(a1, a2, · · · , ak) denote the graph obtained by connecting two distinct vertices with k independent paths of lengths a1, a2, · · · , ak respectively. Assume that 2 ≤ a1 ≤ a2 ≤ · · · ≤ ak. We prove that the graph θ(a1, a2, · · · , ak) is chromatically unique if ak < a1 + a2, and find examples showing that θ(a1, a2, · · · , ak) may not be chromatically unique if ak = a1 + a2.

Let m be a fixed positive integer. For any positive integer n, we define the arithmetical function am(n) as the integer part of the m-th root of n. That is, am(n) = [n 1 m ], where [x] denotes the greatest integer not exceeding to x. For example, a2(1) = 1, a2(2) = 1, a2(3) = 1, a2(4) = 2, a2(5) = 2, a2(6) = 2, a2(7) = 2, a2(8) = 2, a2(9) = 3, a2(10) = 3, · · · . In [1], Professor F. Smarandach...

This note investigates πT,c1,c2(a1,a2)=P(supt∈[0,T](σ1B(t)−c1t)>a1,supt∈[0,T](σ2B(t)−c2t)>a2), where {B(t):t≥0} is a standard Brownian motion, with T>0,σ1,σ2>0,c1,c2∈R. We derive explicit formula for the probability πT,c1,c2(a1,a2) and find its asymptotic behavior both in so called many-source high-threshold regimes.

Phospholipase A2 values increase in serum in various inflammatory states, infections, and postoperatively in surgical patients. Several organs, including the liver and spleen have been suggested as sources of circulating phospholipase A2. The purpose of the present work was to examine the possible role of the spleen as a source of elevated serum concentrations of phospholipase A2 after surgery....

Let A2(n, d) be the maximum size of a binary code of length n and minimum distance d. In this paper we present the following new lower bounds: A2(18, 4) ≥ 5632, A2(21, 4) ≥ 40960, A2(22, 4) ≥ 81920, A2(23, 4) ≥ 163840, A2(24, 4) ≥ 327680, A2(24, 10) ≥ 136, and A2(25, 6) ≥ 17920. The new lower bounds are a result of a systematic computer search over transitive permutation groups.

We studied antegrade concealed conduction of atrial extrastimuli (A2) that blocked in the atrioventricular (AV) node in eight subjects, using a third extrastimulus (A3), coupled at decreasing coupling intervals to A2. Three A1-A2 intervals were tested in each subject: late (just shorter than AV nodal effective refractory period), intermediate, and early (just longer than atrial functional refra...