Curvature measurement as a tool for the analysis of morphometric variation using Drosophila wings as a model

This article describes the use of geometric measurements of continuous, discrete parameters to studymorphometric variation in the wing cells of two sibling species, Drosophila mercatorum and Drosophilaparanaensis. To validate the results, the same wing samples were also analyzed using truss networks andpartial warps, in addition to a comparison with the ellipse method. The use of discriminative measurementsin conjunction with a Bayesian-based classification method yielded a relatively high number of correctclassifications for new individuals. These results compared favorably with those obtained using trussnetworks, partial warps and the ellipse method. These findings indicate that continuous curvature and arclength measurements may be useful parameters for the morphometric analysis of insect wings and possiblyother biological structures and shapes.

Morphometric features and chromatin condensation abnormalities evaluated by toluidine blue staining in bull spermatozoa

In this article, we investigated the correlation between the morphometric features of sperm heads and abnormalities in chromatin condensation using computational image analysis of sperm smears stained with toluidine blue. The chromatin structure was characterized in terms of the average gray-level intensity and the corresponding coefficient variation based on images of the head. The geometry of the sperm heads was determined based on several morphometric measurements, including the area, perimeter, width, length, width: length ratio, ellipticity, shape factor, Fourier descriptor and symmetry. The correlation between the chromatin structure and the geometrical properties was evaluated. The correlation coefficients between the morphometric features and chromatin alterations varied substantially from sample to sample, although a normal morphology was found in heads with or without abnormalities in chromatin condensation. Variations in the abnormalities in chromatin condensation influenced the head morphology in different ways. The finding that spermatozoa with chromatin abnormalities did not necessarily show morphological alterations demonstrates the need for the morphological analysis of sperm to be followed by an evaluation of chromatin structure.

Gramáticas vetoriais estocásticas para sínteses de estruturas neurais / Stochastic vectorial grammars for neural structures syntesis

Este artigo propõe o uso de gramáticas vetoriais estocásticas para a produção de redes neurais artificiais morfologicamente mais realísticas.