Curvature Integration in a 5D Kernel for Extracting Vessel Connections in Retinal Images.

Tree-like structures, such as retinal images, are widely studied in computer-aided diagnosis systems for large-scale screening programs. Despite several segmentation and tracking methods proposed in the literature, there still exist several limitations specifically when two or more curvilinear structures cross or bifurcate, or in the presence of interrupted lines or highly curved blood vessels. In this paper, we propose a novel approach based on multi-orientation scores augmented with a contextual affinity matrix, which both are inspired by the geometry of the primary visual cortex (V1) and their contextual connections.

Local and Global Gestalt Laws: A Neurally Based Spectral Approach.

This letter presents a mathematical model of figure-ground articulation that takes into account both local and global gestalt laws and is compatible with the functional architecture of the primary visual cortex (V1). The local gestalt law of good continuation is described by means of suitable connectivity kernels that are derived from Lie group theory and quantitatively compared with long-range connectivity in V1. Global gestalt constraints are then introduced in terms of spectral analysis of a connectivity matrix derived from these kernels.

Recovery in apple trees infected with the apple proliferation phytoplasma: an ultrastructural and biochemical study.

ABSTRACT Localization of hydrogen peroxide (H(2)O(2)) and the roles of peroxidases, malondialdehyde, and reduced glutathione in three apple cultivars were compared in healthy trees, trees infected with apple proliferation phytoplasma (APP), and trees that had recovered from the infection. In recovered apple trees, symptoms of the disease and the pathogen had disappeared from the canopy, but phytoplasmas remained in the roots. H(2)O(2) was detected cytochemically by its reaction with cerium chloride to produce electron-dense deposits of cerium perhydroxides.

Peripheral arterial occlusive disease: role of MR angiography.

Purpose: Magnetic resonance angiography (MRA) has recently become instrumental in the diagnosis of arterial disease in various body districts and is gaining an increasingly important role in the study of peripheral vascularisation. The aim of our study was to evaluate the reliability of MRA using digital subtraction angiography (DSA) as the reference standard.

Materials And Methods: Between November 2003 and August 2004, 30 patients with known peripheral arterial disease were studied by MRA and DSA.

Cell wall immobilisation and antioxidant status of Xanthoria parietina thalli exposed to cadmium.

Total and cell wall-bound cadmium and the major antioxidants were measured in thalli of the lichen Xanthoria parietina (L.) Th. Fr.

Cadmium distribution and effects on ultrastructureand chlorophyll status in photobionts and mycobionts of Xanthoria parietina.

In this work, we tried to go deeper inside distribution and toxicity of cadmium (Cd) in the macrolichen Xanthoria parietina (L.) Th. Fr.

Noninvasive evaluation of coronary artery stents patency after PTCA: role of Multislice Computed Tomography.

Purpose: Restenosis of a coronary artery treated with stent implantation is a well-known process that can compromise over time the success of a coronary angioplasty and, accordingly, treated patients must undergo periodic controls. We have recently witnessed a shift towards a greater use of Multi-slice CT (msCT) in the study of coronary disease without its precise indications and limits having yet been underlined. The purpose of our study is to assess the role of msCT in the follow-up of patients treated with coronary angioplasty.

Responses of Xanthoria parietina thalli to environmentally relevant concentrations of hexavalent chromium.

Thalli of the lichen Xanthoria parietina (L.) Th. Fr.

Catharanthus roseus L. plants and explants infected with phytoplasmas: alkaloid production and structural observations.

The results of several experiments concerning the presence and composition of alkaloids in different tissues (stems, leaves, roots) of Catharanthus roseus L. plants and explants, healthy and infected by clover phyllody phytoplasmas, are reported. The alkaloids extracted and determined by the reverse phase high-pressure liquid chromatography were vindoline, ajmalicine, serpentine, vinblastine, and vincristine.

Cytochemical localization of calcium and X-ray microanalysis of Catharanthus roseus L. infected with phytoplasmas.

The potassium pyroantimonate (KPA) Ca(2+) precipitation technique, X-ray microanalysis and Electron Energy Loss Spectroscopy carried out by transmission electron microscopy were used to analyze the Ca(2+) distribution in Catharanthus roseus L. leaves infected with phytoplasmas belonging to different taxonomic groups, and in phytoplasma cells. The analysis revealed that the distribution of Ca(2+) was different in healthy and diseased plants (where the KPA deposits were numerous) and no differences were observed in the tissues of the three types of infected C.

[Calcium score quantification using new techniques and its prognostic role in various subgroups of patients].

Coronary artery disease is the first cause of mortality in industrialized countries notwithstanding the diagnostic and therapeutic progresses. Electron beam computed tomography and multislice computed tomography with calcium score software seem to have an important role in the early diagnosis of coronary artery disease. Coronary calcium is associated with a high probability of subclinical atherosclerosis.

Cytological modifications in maize plants infected by barley yellow dwarf virus and maize dwarf mosaic virus.

Three inbred lines of maize (33-16, MO17 and B73) differing in their susceptibility to Barley yellow dwarf virus and Maize dwarf mosaic virus were studied to compare the ultrastructural modifications induced by the two viruses in leaf tissues of different age. The results demonstrate that the alterations induced by the two viruses in the different maize lines could depend on the particular line tested.

Histopathology and polyphenol content in plants infected by phytoplasmas.

The alterations of cell walls and the localization of several compounds such as polyphenols, suberin, lignin, in plum and apple plants infected with plum leptonecrosis (PLN) and apple proliferation (AP) phytoplasmas respectively, were investigated. Catharanthus roseus plants, infected with AP or PLN were also studied. The 4,6-diamidino-2-phenylindole (DAPI) test and transmission electron microscopy showed the presence of phytoplasmas in all infected plants.

Primary endoleakage in endovascular treatment of the thoracic aorta: importance of intraoperative transesophageal echocardiography.

Objectives: Endovascular treatment of the thoracic aorta has developed as an efficacious alternative to open surgical repair. However, despite the high primary success rate, perigraft leakage constitutes the major concern in long-term follow-up. Endoleaks are widely reported both in abdominal and thoracic endovascular series and are usually identified by intraoperative angiography.

X-ray microanalysis of leaf tumors from maize plants experimentally infected with maize rough dwarf virus: scanning and transmission electron microscopic study.

X-Ray microanalysis, performed by both scanning and transmission electron microscopes equipped with energy-dispersive spectrometers (EDS), was used to analyze the element distribution in phloem tumors induced by maize rough dwarf virus (MRDV) in Zea mays L. The content of both Si and Ca was lower in tumors than in the nontumoral surrounding tissues. The Si content increased in old tumors where this element was mainly concentrated in the trichomes growing at their surface.