This paper discusses the geometrical properties of a radiolarian skeletal structure, namely, that of genus Didymocyrtis. We characterized the evolution of skeletal structures and analyzed the structures using geometry. We defined two ratios in order to quantify the geometrical properties of Didymocyrtis and verified that the two ratios changed with their phylogenic evolution. We also used the 3D skeletal data of a specimen of species D. tetrathalamus, which was obtained through micro X-ray CT. The cortical shell obtained in the 3D data was projected onto a spherical surface, and we determined the centers of the pores. Our analysis revealed that the number of pores is approximately 200 and their distribution is not regular. We also determined that the column-like parts of the skeleton, which connect the inner and upper parts of the specimen, do not lie on a plane and their intervals are not equal.

In this paper, a new Haar wavelet-based approach to the detection and localization of defects in grey-level texture images is presented. This new approach explores space localization properties of the discrete Haar wavelet transform (HT) and generates statistically-based parameterized texture defect detection criteria. The criteria provide the user with a possibility to control the percentage of both the actually defect-free images detected as defective and/or the actually defective images detected as defect-free, in the class of texture images under investigation. The experiment analyses samples of ceramic tiles, glass samples, as well as fabric scraps, taken from real factory environment.

Oval cells are the progeny of facultative stem cells found in the periportal areas in response to liver injury in experimental animals and humans. The aims of this study were to describe the morphological, stereological and morphometric features of oval cells, and to compare them with those of bile duct cells and hepatocytes. It was also aimed to study the fate of oval cells by morphological and morphometric criteria. Rats were given thioacetamide to induce liver injury. The livers from experimental and control groups were processed routinely and stereological and morphometric analysis assessed using a computer image analysis system. Eight morphometric parameters were assessed in oval cells, bile duct cells and hepatocytes from control and experimental rats. Mitoses were observed in both oval cells and hepatocytes. Stereological area fraction analysis indicated that necrosis reached its maximum extent at 30 hours followed by regeneration and almost complete restoration of liver cell parenchyma at 132 hours. Oval cell proliferation reached a peak at 48-52 hours but was not apparent at 132 hours. Morphometric findings have shown increases in the nuclear diameter and nuclear area of oval cells with changes in the roundness and contours ratios of the nuclear membrane. It is concluded from this study that in thioacetamide treated rats, the liver responds to injury by bile ductal proliferation in the periportal areas which, accompanied by hepatocyte regeneration, leads to restoration of the hepatic parenchyma. At a subcellular morphological level the nuclei of oval cells showed a progressive change to a hepatocyte phenotype from that of a normal biliary cell, suggesting the differentiation of these cells into hepatocytes.