The interval function (in the sense of H.M.Mulder) is an important tool for studying those properties of a connected graph that depend on the distance between vertices. An axiomatic characterization of the interval function of a connected graph was published by Nebeský in 1994. In Section 2 of the present paper, a simpler and shorter proof of that characterization will be given. In Section 3, a...

One of the main causes of mortality is atherosclerosis which leads to sudden cardiac attack. Frequently the first symptom of coronary artery disease is acute coronary syndromes (ACS) which is mainly caused by the rupture of a coronary artery. Histopathological studies have revealed that generally atherosclerotic plaque rupture results in thrombi. Atherosclerosis components of clinical importanc...

Recently, the concept of overall connectivity of a graph G, TC(G), was introduced as the sum of vertex degrees of all subgraphs of G. The approach of more detailed characterization of molecular topology by accounting for all substructures is extended here to the concept of overall distance OW(G) of a graph G, defined as the sum of distances in all subgraphs of G, as well as the sum of eth-order...

Modern imaging systems are able to produce a rich and diverse array of information, regarding various facets of anatomy and function. The quantity of information produced by these systems is so bountiful, however, as to have the potential to become a hindrance to clinical assessment. In the context of serial image evaluation, computer-based change detection and characterization is one important...

The use of organometallic fragments as cationization reagents for matrix-assisted laser-desorption-ionization time-of-flight mass spectrometry (MALDI-TOF-MS) of polystyrene (PS) and polypropene (PP) is reported. Reaction of [Ru(C5H5)(NCCH3)3][PF6] (1a) with PS samples of numerical mass average Mn 1430 /135 000 in a ratio [Ru]/[PS] /1/1 to 3/1 favours effective ionization of the polymer by MALDI...

In this paper, we present characterizations of pairs of graphs whose join graphs are 2-minimally nonouterplanar. In addition, we present a characterization of pairs of graphs whose join graphs are 2-minimally nonouterplanar in terms of forbidden subgraphs.

For the family of graphs with xed-size vertex cover k, we present all of the forbidden minors (obstructions), for k up to ve. We derive some results, including a practical nite-state recognition algorithm, needed to compute these obstructions.

A graph G is coordinated if the minimum number of colors that can be assigned to the cliques of H in such a way that no two cliques with non-empty intersection receive the same color is equal to the maximum number of cliques of H with a common vertex, for every induced subgraph H of G. Coordinated graphs are a subclass of perfect graphs. The list of minimal forbidden induced subgraphs for the c...