Spanish architect Antoni Gaudı́ drew on natural precedent to create fantastic organically inspired designs. This paper examines some common motifs in his works, and demonstrates how simple geometric operations can be applied to polyhedral models to achieve similar results. The importance of the partial hyperbolic paraboloid surface (or hypar) is discussed in this context. r 2007 Elsevier Ltd. Al...

Currently, there are a number of motif detection tools available that possess unique functionality. These tools often report different motifs, and therefore use of multiple tools is generally advised since common motifs reported by multiple tools are more likely to be biologically significant. However, results produced by these different tools need to be compared and existing similarity detecti...

Sliceform paper art is an art form where long strips of paper are cut, folded and slotted together to form intricate geometric configurations. We present a system that streamlines the design process for such artwork, which are conventionally highly time-consuming to assemble. Main features of the system include a powerful user interface for specification of custom pattern motifs and an algorith...

Much attention has recently been given to the statistical significance of topological features observed in biological networks. Here, we consider residue interaction graphs (RIGs) as network representations of protein structures with residues as nodes and inter-residue interactions as edges. Degree-preserving randomized models have been widely used for this purpose in biomolecular networks. How...

Noncanonical RNA motifs help define the vast complexity of RNA structure and function, and in many cases, these loops and junctions are on the order of only ten nucleotides in size. Unfortunately, despite their small size, there is no reliable method to determine the ensemble of lowest energy structures of junctions and loops at atomic accuracy. This chapter outlines straightforward protocols u...

Viroids are noncoding RNAs that infect plants. In order to establish systemic infection, these RNAs must traffic from an initially infected host cell into neighboring cells and ultimately throughout a whole plant. Recent studies have identified structural motifs in a viroid that are required for trafficking, enabling further studies on the mechanisms of their function. Some cellular proteins in...

MOTIVATION Transcription regulatory protein factors often bind DNA as homo-dimers or hetero-dimers. Thus they recognize structured DNA motifs that are inverted or direct repeats or spaced motif pairs. However, these motifs are often difficult to identify owing to their high divergence. The motif structure included explicitly into the motif recognition algorithm improves recognition efficiency f...

Most biological actions of proteins depend on some typical parts of their three-dimensional structure, called 3D motifs. To automatically discover corresponding 3D motifs between proteins, we propose a new 3D substructure matching algorithm based on geometric hashing techniques. The key feature of the method is the introduction of a 3D reference frame attached to each amino acid. This allows to...

Coiled coils are important protein-protein interaction motifs with high specificity that are used to assemble macromolecular complexes. Their simple geometric organization, consisting of alpha helices wrapped around each other, confers remarkable mechanical properties. A geometrical and mechanical continuous model taking into account sequence effects and based on the superhelical winding of the...

Road sign recognition is one of the core technologies in Intelligent Transport Systems. In the current study, a robust and real-time method is presented to identify and detect the roads speed signs in road image in different situations. In our proposed method, first, the connected components are created in the main image using the edge detection and mathematical morphology and the location of t...