We prove that the bounded complex of an affine oriented matroid is pure and collapsible. We also generalize Zaslavsky’s Central Decomposition Theorem for hyperplane arrangements to affine oriented matroids.

Ehrenborg noted that all tilings of a bipartite planar graph are encoded by its cubical matching complex and claimed this is collapsible. We point out to an oversight in his proof explain why these complexes can be the disjoint union two or more collapsible complexes. also prove links suspensions up homotopy. Furthermore, we extend definition graphs not necessarily bipartite, show either contra...

PURPOSE To propose an alternative method to characterize postocclusion surge using a collapsible artificial anterior chamber to replace the currently used rigid anterior chamber model. SETTING Fundación Oftamológica Los Andes, Santiago, Chile. METHODS The distal end of a phacoemulsification handpiece was placed inside a compliant artificial anterior chamber. Digital recordings of chamber pr...

Thomassen conjectured that every 4-connected line graph is Hamiltonian. Chen and Lai [Z.-H. Chen, H.-J. Lai, Reduction techniques for super-Eulerian graphs and related topics— an update, in: Ku Tung-Hsin (Ed.), Combinatorics and Graph Theory, vol. 95, World Scientific, Singapore/London, 1995, pp. 53–69, Conjecture 8.6] conjectured that every 3-edge connected, essentially 6-edge connected graph ...

For an integer s > 0 and for u, v ∈ V (G) with u ≠ v, an (s; u, v)-trail-system of G is a subgraphH consisting of s edge-disjoint (u, v)-trails. A graph is supereulerianwithwidth s if for any u, v ∈ V (G) with u ≠ v, G has a spanning (s; u, v)-trail-system. The supereulerian width μ(G) of a graph G is the largest integer s such that G is supereulerian with width k for every integer kwith 0 ≤ k ...

The upper airway muscles play an important role in maintaining upper airway collapsibility, and the incidence of sleep-disordered breathing increases with age. We hypothesize that the increase in airway collapsibility with increasing age can be linked to changes in upper airway muscle mechanics and structure. Eight young (Y: 6 mo) and eight old (O: 30 mo) Fischer 344 rats were anesthetized and ...

BACKGROUND AND OBJECTIVES We sought to determine whether training with a simple collapsible mobile box trainer leads to improved performance of fundamental laparoscopic skills (FLSs) during a 6-month interval versus validated laparoscopic box trainers and virtual-reality trainers, only accessible at a simulation training center. METHODS With institutional review board approval, 20 first- and ...