the colorful paths and rainbow paths have been considered by severalauthors.a colorful directed path in a digraph $g$ is a directed path with $chi(g)$ vertices whose colors are different. a $v$-colorful directed path is such a directed path, starting from $v$. we prove that for a given $3$-regular triangle-free digraph $g$ determining whether there is a proper $chi(g)$-coloring of $g$such that ...

This paper introduces five new density and accuracy metrics for aerial point clouds that address the complexity objectives of modern, dense laser scans urban scenes. The describe (1) vertical surface (points per area on surfaces); (2) as a function horizontal density; (3) accuracy; decomposition error into (4) within-pass (5) cross-pass components. Specifically considered is coverage practice o...

In the last decade, the use of phylogenetic networks to analyze the evolution of species whose past is likely to include reticulation events, such as horizontal gene transfer or hybridization, has gained popularity among evolutionary biologists. Nevertheless, the evolution of a particular gene can generally be described without reticulation events and therefore be represented by a phylogenetic ...

About half of the monophasic horizontal cells in carp retina receive input from both red- and green-sensitive cones. Since the horizontal cells feed back to cones, the color and feedback pathways result in wavelength- and intensity-dependent changes of the dynamics and of the receptive field amplitude profile of the horizontal cell responses. In this paper we present a quantitative model that d...

Previous work has shown that molecular phylogenies of plastids, cyanobacteria, and proteobacteria based on the rubisco (ribulose-1,5-bisphosphate carboxylase/oxygenase) genes rbcL and rbcS are incongruent with molecular phylogenies based on other genes and are also incompatible with structural and biochemical information. Although it has been much speculated that this is the consequence of a si...

In this work, the melting process of compounds containing nanoparticles of NePCM in a square hole with different angles affected by two pairs of well-spring heat source on horizontal walls was numerically investigated. Four different configurations of elements were employed to investigate the effect of changes in the position of elements on the horizontal walls of the well-spring landscape on t...

purpose: compaison of excyclotorsion induced by horizontal transposition of vertical rectus muscles versus vertical transposition of horizontal rectus muscles in rabbit eyes. methods: in this exprimental study, group 1 underwent full tendon nasal transposition of the superior rectus and full tendon temporal transposition of the inferior rectus (10 adult rabbits); group 2 underwent superior tran...