Lorna Stewart

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Bipartite graphs and permutation graphs are two well known subfamilies of the perfect graphs. Neither of these families is contained in the other, and their intersection is nonempty. This paper shows that graphs which are both bipartite and permutation graphs have good algorithmic properties. These graphs can be recognized in linear time, and several(More)
An independent set of three vertices such that each pair is joined by a path that avoids the neighborhood of the third is called an asteroidal triple. A graph is asteroidal triple-free (AT-free) if it contains no asteroidal triples. The motivation for this investigation was provided, in part, by the fact that the AT-free graphs provide a common(More)
OBJECTIVE Since the diagnosis of delayed-onset posttraumatic stress disorder (PTSD) was introduced in DSM-III, there has been controversy over its prevalence and even its existence. The authors sought to resolve discrepant findings concerning the prevalence of delayed-onset PTSD by conducting a systematic review of the evidence. METHOD A literature search(More)
A graph is an interval graph if it is the intersection graph of intervals on a line. Interval graphs are known to be the intersection of chordal graphs and asteroidal triple-free graphs, two families where the well-known Lexicographic Breadth First Search (LBFS) plays an important algorithmic and structural role. In this paper we show that interval graphs(More)
Differences in symptoms, trauma exposure, dissociative and emotional reactions to trauma, and subsequent life stress in war veterans reporting immediate-onset or delayed-onset posttraumatic stress disorder (PTSD) or no PTSD were investigated. The role of life stress in delayed-onset PTSD was also studied. Retrospective interviews were conducted with 142(More)
An independent set of three vertices is called an asteroidal triple if between each pair in the triple there exists a path that avoids the neighborhood of the third. A graph is asteroidal triplefree (AT-free) if it contains no asteroidal triple. The motivation for this investigation is provided, in part, by the fact that AT-free graphs offer a common(More)
An independent set fx; y; zg is called an asteroidal triple if between any pair in the triple there exists a path that avoids the neighborhood of the third. A graph is referred to as AT-free if it does not contain an asteroidal triple. We present a simple linear-time algorithm to compute a dominating path in a connected AT-free graph.
Since their introduction by Claude Berge in the early 1960s [2], perfect graphs have attracted considerable attention, and many interesting families of graphs have been shown to be contained in the perfect graphs. Perfect graphs are graphs in which the maximum clique size is equal to the chromatic number for every induced subgraph. One of the problems which(More)