We prove that the problem of deciding whether a 2or 3-dimensional simplicial complex embeds into R is NP-hard. This stands in contrast with the lower dimensional cases which can be solved in linear time, and a variety of computational problems in R like unknot or 3-sphere recognition which are in NP∩ co-NP (assuming the generalized Riemann hypothesis). Our reduction encodes a satisfiability ins...

We study the complexity of two problems in simultaneous graph drawing. The first problem, GRACSIM DRAWING, asks for finding a simultaneous geometric embedding of two graphs such that only crossings at right angles are allowed. The second problem, K-SEFE, is a restricted version of the topological simultaneous embedding with fixed edges (SEFE) problem, for two planar graphs, in which every priva...

Introduction: Our previous study has showed that chronic administration of magnesium oxide nanoparticles (MgO NP) can reduce anxiety in adult male rat. In this study the effects of MgO NP on anxiety induced by morphine withdrawal were investigated in adult male mice. Methods: Adult male NMRI mice (weighing 27 ± 3 g) divided into groups: control, receiving intraperitoneal (i.p.) injection...

Korean red ginseng (KRG) possesses neuroprotective activity. However, the potential neuroprotective value of KRG for the striatal toxicity is largely unknown. We investigated whether KRG extract (KRGE) could have a neuroprotective effect in a 3-nitropropionic acid- (3-NP) induced (i.p.) Huntington's disease (HD) model. KRGE (50, 100, and 250 mg/kg/day, p.o.) was administrated 10 days before 3-N...