The relationship between geometric folding of the chromatin fiber and genome function is a key issue in cell biology. We propose different approaches based on statistical shape theory to investigate the geometric variability of chromatin folding in nuclei of interphase human fibroblasts. Our main purpose is to assess the degree of variability of folding of the chromatin fiber, measured by fluor...

Despite inherent errors, cephalometric superimpositions are currently the most widely used means for assessing sagittal and vertical tooth movements. The purpose of this study was to compare three-dimensional (3D) digital model superimposition with cephalometric superimposition. The material was collected from initial and final maxillary casts and lateral cephalometric radiographs of 30 patient...

We present the Procrustes measure, a novel measure based on Procrustes rotation that enables quantitative comparison of the output of manifold-based embedding algorithms (such as LLE (Roweis and Saul, 2000) and Isomap (Tenenbaum et al, 2000)). The measure also serves as a natural tool when choosing dimension-reduction parameters. We also present two novel dimension-reduction techniques that att...

The conventional object-oriented paradigm provides part-of, inheritance and delegation relations as means for composition of objects. Although inheritance and delegation represent a considerable improvement over the module-based third generation languages, we have experienced that certain types of composability cannot be expressed using the aforementioned techniques. In some cases, the software...

Bioinformatics sample summaries often involve distances or the conversion of similarities to dissimilarities, while Procrustes methods can proceed either via distances or via the shape coordinates underlying those distances. There is a distance–distance statistical method, currently increasing in popularity in some of my applications domains, that is at once simple, intuitive, and quite wronghe...

One of the aims of forensic science is to determine the identities of victims of crime. In some cases the investigators may have ideas as to the identities of the victims and in these situations, ante mortem photographs of the victims could be used in order to try and establish identity through skull-photo superimposition. The aim of this study was to evaluate the accuracy of a newly developed ...

OBJECTIVES To test the applicability, accuracy, precision, and reproducibility of various 3D superimposition techniques for radiographic data, transformed to triangulated surface data. METHODS Five superimposition techniques (3P: three-point registration; AC: anterior cranial base; AC + F: anterior cranial base + foramen magnum; BZ: both zygomatic arches; 1Z: one zygomatic arch) were tested u...

Two-dimensional shape models have been successfully applied to solve many problems in computer vision, such as object tracking, recognition, and segmentation. Typically, 2D shape models are learned from a discrete set of image landmarks (corresponding to projection of 3D points of an object), after applying Generalized Procustes Analysis (GPA) to remove 2D rigid transformations. However, the st...

Superimposition of serial Cone Beam Computed Tomography (CBCT) scans has become a valuable tool for three dimensional (3D) assessment of treatment effects and stability. Voxel based image registration is a newly developed semi-automated technique for superimposition and comparison of two CBCT scans. The accuracy and reproducibility of CBCT superimposition on the anterior cranial base or the zyg...