UNLABELLED Misregistration between attenuation and emission images causes artifactual abnormalities on cardiac PET images that result in false-positive defects. This study determines the frequency and mechanisms of misregistration artifacts, identifies their predictors, and validates a method for their routine clinical identification, prevention, or correction. METHODS We performed 1177 conse...

An octilinear drawing of a planar graph is one in which each edge is drawn as a sequence of horizontal, vertical and diagonal at 45◦ line-segments. For such drawings to be readable, special care is needed in order to keep the number of bends small. As the problem of finding planar octilinear drawings of minimum number of bends is NP-hard [16], in this paper we focus on upper and lower bounds. F...

A graph is Bk-VPG when it has an intersection representation by paths in a rectangular grid with at most k bends (turns). It is known that all planar graphs are B3-VPG and this was conjectured to be tight. We disprove this conjecture by showing that all planar graphs are B2-VPG. We also show that the 4-connected planar graphs constitute a subclass of the intersection graphs of Z-shapes (i.e., a...

Monoaminergic neurons [serotonergic (5-HT) and dopaminergic (mdDA)] in the brainstem project axons along the anterior-posterior axis. Despite their important physiological functions and implication in disease, the molecular mechanisms that dictate the formation of these projections along the anterior-posterior axis remain unknown. Here we reveal a novel requirement for Wnt/planar cell polarity ...

A holographic display system combining the spatial- and time-multiplexing together in one system is proposed. The system is constructed by multiple planar aligned spatial-light-modulators (SLMs). A shiftable cylindrical lens is introduced in to build up an "equivalent SLM" by seamlessly linked horizontal images of the SLMs, which are tiled in a time-sequential manner. The proposed system can re...

A visibility drawing of a plane graph G is a drawing of G where each vertex is drawn as a horizontal line segment and each edge is drawn as a vertical line segment such that the line segments use only grid points as their endpoints. The area of a visibility drawing is the area of the smallest rectangle on the grid which encloses the drawing. A minimum-area visibility drawing of a plane graph G ...

A visibility representation of a graph G is to represent the nodes of G with non-overlapping horizontal line segments such that the line segments representing any two distinct adjacent nodes are vertically visible to each other. If G is a plane graph, i.e., a planar graph equipped with a planar embedding, a visibility representation of G has the additional requirement of reflecting the given pl...

A graph with an ordered k-partition of the vertices is radial level planar if there is a strictly outward drawing on k concentric levels without crossings. Radial level planarity extends level planarity, where the vertices are placed on k horizontal lines and the edges are routed strictly downwards without crossings. The extension is characterised by rings, which are certain level non-planar bi...