bluuebunny/crossref_metadata_2025 huggingface dataset:
ESTIMATION OF FIBRE ORIENTATION FROM DIGITAL IMAGES
Authors: Kärkkäinen Salme , Jensen Eva B Vedel
Published: July 2011

In this paper, estimation of fibre orientation is studied for fibre systems observable as a blurred greyscale image. The estimation method is based on scaled variograms observed along a set of sampling lines in different directions. The parameters of the orientation distribution are obtained numerically. Simulated data are used to study the statistical properties of the method.
MEASUREMENTS OF STRAIN FIELDS DUE TO NANOSCALE PRECIPITATES USING THE PHASE IMAGE METHOD
Authors: Donnadieu Patricia , Matsuda Kenji , Epicier Thierry , Douin Joel
Published: July 2011

Owing the phase image method (Hytch, 1998), strain fields can be derived from HREM images. The method is here applied to the nanoscale precipitates responsible for hardening in Aluminum alloys. Since the method is a very sensitive one, we have examined the impact of several aspects of the image quality (noise, fluctuations, distortion). The strain field information derived from the HREM image analysis is further introduced in a simulation of the dislocation motion in the matrix.
ROUGHNESS CHARACTERIZATION OF AN INDOOR ENVIRONMENT
Authors: Douiri Nisrine , Khoudeir Majdi , Olivier Christian
Published: July 2011

For a transmission at 60 GHz inside the buildings, the models of propagation currently developed do not take into account the 3D roughness of surfaces under consideration. In this paper, we deal with the evaluation of the 3D roughness of surfaces in this kind of environment. An indoor environment includes different types of surfaces but the most representative of 3D roughness are walls, ceiling and floor. We propose a method to characterise the 3D roughness of these surfaces by constructing an image space made up of the original image, the image of gradient, the image of curvature and the image of the angles between the perpendicular to the grey level surface and the perpendicular to the whole image. The method we have developed is based, first, on the study of correlation variations of our image space, and second on a frequency analysis of the angle image histograms. The elaborated criteria allowed us to classify the surfaces studied.
THE APPLICATION OF STEREOLOGY METHOD FOR ESTIMATING THE NUMBER OF 3D BaTiO3 – CERAMIC GRAINS CONTACT SURFACES
Authors: Mitić Vojislav V , Nikolić Zoran S , Mitrović Ivona , Jordović Branka , Brankov Vladimir
Published: July 2011

Methods of stereological study are of great importance for structural research of electronic ceramic materials including BaTiO3-ceramic materials. The broad application of ceramics, based on barium-titanate, in advanced electronics nowadays demands a constant research of its structure, that through the correlation structureproperties, a fundamental in the basic materials properties prognosis triad (technology-structure-properties), leads to further prognosis and properties design of these ceramics. Microstructure properties of BaTiO3- ceramic material, expressed in grains' boundary contact, are of basic importance for electric properties of this material, particularly the capacity. In this paper, a significant step towards establishing control under capacitive properties of BaTiO3-ceramics is being done by estimating the number of grains contact surfaces. Defining an efficient stereology method for estimating the number of BaTiO3-ceramic grains contact surfaces, we have started from a mathematical model of mutual grains distribution in the prescribed volume of BaTiO3-ceramic sample. Since the real microstructure morphology of BaTiO3-ceramics is in some way disordered, spherical shaped grains, using computer-modelling methods, are approximated by polyhedra with a great number of small convex polygons. By dividing the volume of BaTiO3-ceramic sample with the definite number of parallel planes, according to a given pace, into the intersection plane a certain number of grains contact surfaces are identified. According to quantitative estimation of 2D stereological parameters the modelled 3D internal microstructure is obtained. Experiments were made by using the scanning electronic microscopy (SEM) method with the ceramic samples prepared under pressing pressures up to 150 MPa and sintering temperature up to 1370°C while the obtained microphotographs were used as a base of confirming the validity of presented stereology method. This paper, by applying computer stereology method for estimating the number of grains contact surfaces, makes possible a further insight into the microstructure of BaTiO3-ceramics with the final aim to design new properties of electronic materials based on barium - titanate ceramics.
A NEW, OTHER THAN ACOUSTIC, QUANTIFICATION METHOD FOR ENDOCARDIUM DETECTION IN ECHOCARDIOGRAPHIC IMAGES
Authors: Wojnar Leszek , Szydlowski Leslaw , Marek-Szydlowska Teresa
Published: July 2011

A new, semiautomatic algorithm for tracing outlines of endocardium of newborns that are detectable in echocardiographic images is presented. The main advantage of the method proposed is its low sensitivity to operator errors. Moreover, in contrast to the acoustic quantification method (AQ), an analysis of archive and low quality images is available, as well as the traces obtained are smooth and free of artefacts. Thus, the new solution allows for further, fully automatic, quantitative characterization of the shape and size of the ventricle. The results are compared with manual tracings in order to demonstrate the advantage of the newly developed method. Some results from massive research on newborns with various heart defects are also presented.
OBSERVING TUMOR VASCULARITY NONINVASIVELY USING MAGNETIC RESONANCE IMAGING
Authors: Haacke Mark E , Herigault Gwen , Kido Daniel , Tong Karen , Obenaus Andre , Yu Yingjian , Reichenbach Juergen R
Published: July 2011

A new approach to tumor discrimination using magnetic resonance imaging is reported. The susceptibility difference between venous blood and the surrounding tissue is used to generate contrast. This approach is able to exquisitely reveal small veins even those which are smaller than a voxel. Using this method, it is possible to visualize the primary draining veins within tumors better than contrast enhanced magnetic resonance imaging methods that require a contrast agent or even conventional angiography. The ability to highlight deoxygenated blood may lead to the possibility of differentiating benign from malignant tumors noninvasively.
ESTIMATION OF THE NUMBER OF NEURONS IN THE HIPPOCAMPUS OF RATS WITH PENICILLIN INDUCED EPILEPSY
Authors: Akdogan Ilgaz , Unal Nedim , Adiguzel Esat
Published: July 2011

Epilepsy is a neurological disease arising from strong and uncontrollable electrical firings of a group of neurons in the central nervous system. Experimental epileptic models have been developed to assess the physiopathology of epileptic seizures. This study was undertaken to estimate the number of neurons in the rat hippocampus with penicillin induced epilepsy, using a stereological method, "the optical fractionator". In the experimental group, 500 IU penicillin-G was injected intra-cortically, and in the control group, the same volume of saline was administered. A week later, the animals were decapitated and their brains were removed by craniatomy. Frozen brains were cut with a thickness of 150 ěm in a cryostat. Sections were collected by systematic random sampling and stained with hematoxylen-eosin. Microscopic images of pyramidal cell layers from hippocampus CA1, CA2 and CA3 subfields were then transferred to a monitor, using a 100x objective (N.A. = 1.25). Using the optical disector method, the neurons were counted in the frames and determined with a fractionator sampling scheme. The total pyramidal neuron number was then estimated using the optical fractionator method. The total pyramidal neuron number was found to be statistically lower in the experimental group (mean = 142,888 ± 11,745) than in the control group (mean = 177,953 ± 10,907) (p < 0.05). The results suggest that a decrease in the hippocampal neuronal number in a penicillin model of epilepsy can be determined objectively and efficiently using the optical fractionator method.
QUANTITATIVE IMAGE ANALYSIS OF MICROSTRUCTURE EVOLUTION DURING SOLID STATE SINTERING OF W-Cu
Authors: Popa Ana Maria , Chaix JeanMarc
Published: July 2011

The microstructure evolution of W-Cu composites during solid state sintering at 1050°C is studied on samples quenched after different sintering times. The microstructure is formed by 3 phases: tungsten (W), copper (Cu) and pores. During the process, the initial mixture of W- and Cu-powder is transformed by migration of Cu and rearrangement of W particles. These microstructural changes are studied to identify the underlying phenomena and to control the material properties. Based on experiments performed with two different W powders, this paper deals with various aspects of the quantitative analysis of the observed evolution. A careful preparation of the images is necessary. The porous samples are impregnated with a resin under vacuum before being cut and carefully polished. Low voltage (<10 kV) is used during image acquisition on a scanning electron microscope. Area fraction measurements are used to check the quality of the images and the segmentation process. Classical measurements are used to study the spreading of Cu onto the surface of W particles: surface area of each phase, area of contact between phases, chord length distributions. New measurements based on classical methods are also developed to distinguish between two mechanisms of Cu migration in the microstructure : Cu spreading on W surface (wetting of the surface), and capillary penetration in the inter-W channels. An analysis of the location of Cu and pores in the space between W particles (inter-W space) is performed using a granulometry based on 2D openings. It evidences the mechanism of capillary penetration of Cu in the inter-W space in the case of small W-particles.
AUTO-SHAPE ANALYSIS OF IMAGE TEXTURES IN FRACTOGRAPHY
Authors: Lauschmann Hynek , Nedbal Ivan
Published: July 2011

The aim of this study is to estimate the velocity of fatigue crack growth (crack growth rate - CGR) from the texture in SEM images of crack surfaces. A simple and quick method is based on fitting training images as a linear combination of several small subimages selected from the images themselves. The size of basic subimages is derived from autocorrelation functions of the image in row and column direction. The selection of basic subimages is based on two indicators: "appeal" evaluating their shape content, and mutual coefficient of correlation. The method is easy to implement and quick in computations, while results of testing application are fully comparable with best ones obtained within textural fractography of fatigue failures.
NUCLEAR MORPHOMETRY IN AFRICAN BREAST CANCER
Authors: Ikpatt Offiong Francis , Kuopio Teijo , Collan Yrjö
Published: July 2011

Three hundred cases of invasive breast cancer diagnosed between 1983 and 1999 in Calabar, Nigeria were analysed to determine the nuclear morphometric variables, and evaluate the prognostic potential of nuclear morphometry in Nigerian breast cancers. The necessary follow-up was available for 129 patients. The nuclear area was the most valuable variable. In the Nigerian material, the mean nuclear area (MNA) (SD) was 89.2 (34.0) μm2. MNA was significantly higher in tumours of the postmenopausal than premenopausal (p = 0.0405), in LN+ than LN- (p = 0.0202) patients, and in tumours over 3 cm than smaller ones (p < 0.0001). There were also significant differences between different clinical stages, histological grades, and histological types of tumours. Significant correlations were observed between MNA and histological grade (r = 0.64), standard mitotic index (r = 0.45) and tumour size (r = 0.20). MNA as a continuous variable was a statistically significant prognosticator in the whole material (p = 0.0281), and among the postmenopausal patients (p = 0.0238). Univariate cox's regression demonstrated one significant grading cutpoint at MNA = 111 μm2, which divided the material into two groups of different survival. The development of a morphometric grading system optimal for the Nigerian material could use the latter cut-point between nuclear scores 2 and 3 in the grading system. The earlier proven cut-point of 47 μm2 could be used between nuclear scores 1 and 2.
CROSS-CORRELATION ANALYSIS OF THE SPATIAL INTERACTIONS BETWEEN TISSUE COMPARTMENTS OF THE RENAL CORPUSCLE
Authors: Mayhew Terry M
Published: July 2011

The renal corpuscle is a multi-compartment unit of kidney morphology which is important for normal ultrafiltration of blood. Its structure is perturbed during ontogeny, disease and experimental manipulation. Transmission electron microscopy and second-order stereological tools (cross covariance and cross correlation functions) were used to examine 3-D spatial interactions between the main tissue compartments (glomerular capillaries, podocytes, mesangium, urinary space) of the renal corpuscle in normal adult rats. Volume densities, covariance and correlation functions were estimated by counting test points (randomly positioned) and linear dipole probes (randomly positioned and orientated) superimposed on random samples of photomontages prepared from ultrathin resin sections. Differences in clustering exist between compartments (at distances < 8 Î¼m, mesangium is the most tightly-clustered and capillaries the least tightly-clustered compartment; > 8 Î¼m, compartments are neither hypodisperse nor hyperdisperse). Despite this, cross correlation functions for linked sets of compartments (capillary-mesangium, capillary-podocytes, capillary-urinary space, mesangium-podocytes, mesangium-urinary space and podocytes-urinary space) did not vary with dipole distance. This indicates that the spatial relations between linked compartments do not favour attraction or repulsion. In addition, inter-individual variation is greater for some linked compartments than others. Variation is less for compartments (capillary-podocyte and capillary-urinary space) which contribute to the ultrafiltration barrier and this probably reflects the structural and functional integration evident at this site as well as the higher volume densities (and smaller inter-subject variation) for capillaries.
THE APPLICATION OF STEREOLOGICAL METHODS FOR THE QUANTITATIVE ANALYSIS OF THE ATHEROSCLEROTIC LESIONS IN RABBITS
Authors: Nachtigal Petr , Semecký Vladimír , Gojová Andrea , Kopecký Martin , Beneš Viktor , Jŭzková Radka
Published: July 2011

Atherosclerosis is a chronic metabolic and inflammatory disease of vascular arteries. Insome cases, it comes the accumulation of the inflammatory cells and extracellular matrix in vessel intima, which lead to the narrowing of the vessel lumen. The aim of this study was introduce stereological methods for the quantification of atherosclerotic changes in the aorta of New Zealand White rabbits in dependence on the period of feeding with atherogenic diet containing 0.4% of cholesterol. The Cavalieri estimator was used for the estimation of the volume of atherosclerotic lesions. The area of the atherosclerotic lesions and the area fraction of free vessel lumen were determined with the image analysis software Lucia. The principle of the point counting method was used for the estimation of the volume fraction of collagen in atherosclerotic lesions and the principle of the optical disector was used for the estimation of the number of cells per unit volume in atherosclerotic lesions. The results obtained by the stereological methods confirmed the induction and progression of atherogenic changes in rabbit vessel wall in cholesterol fed animals. The methods applied in this study will be used in our prospective studies where the effect of hypolipidemic drug treatment on atherogenic process will be monitored
SEPARATION OF THE INTER- AND INTRA-PARTICLE POROSITY IN IMAGES OF POWDER COMPACTS
Authors: Lacaze Jacques , Arnal Alexis , Dupuy Jean-Luc , Poquillon Dominique
Published: July 2011

Powder metallurgy is a highly developed and cheap method of manufacturing reliable materials, either metallic, ceramic or composite. This process was used to make green compacts of iron powders with a high porosity level. This study is part of a project aimed at describing the relationships between mechanical properties and morphological features of such compacts, with particular attention paid to the shape of the grains and the compaction pressure. In this report, a method is proposed to separate the intra grain porosity from the cavities located between particles. The approach is based on the covariogram of images obtained from the surface of the compacts by means of a laser roughometer. To achieve this separation, a model of the structure is proposed which assumes that the distributions of the grains and of the intra-particle cavities are random and independent. Each distribution is characterized by two parameters. A satisfactory agreement is obtained between experimental and calculated covariograms after identification of these parameters.
TOPOLOGICAL LOCALISATION OF DEFECTS AT ATOMIC SCALE
Authors: Jernot Jean-Paul , Jouannot-Chesney Patricia , Lantuéjoul Christian , Nouet Gérard , Ruterana Pierre
Published: July 2011

The problem addressed in this paper is the detection of defects on atomic structures. The procedure proposed is in two steps. At first a tessellation is built starting from the atoms. It consists of a partition of the space into cells, and is used to define the neighbourhood relationships between the atoms. Then, the local contribution to a topological parameter, namely the Euler-Poincare characteristic, is defined and measured for each cell. Within a regular tessellation, made of identical cells, this local contribution is equal to zero. Any local deviation from regularity corresponds to a tessellation containing cells with non-zero contributions. This allows us to locate the defects from a topological criterion and opens the way to a fully automatic detection of interfaces at atomic scale. The procedure is applied in 2D space for the detection of edge dislocations, grain boundaries and twins from HREM models and images. A 3D example is also given to illustrate its generality.
RECOGNITION OF PATTERNS ON FRACTURE SURFACES BY AUTOMATIC IMAGE ANALYSIS
Authors: Jacek Komenda , Barbara Maroli , Lars Höglund
Published: July 2011

Image Classifier, the software package integrated with the MicroGOP2000/S system (Sweden), is applied to quantitatively analyse fracture surfaces. After training the system in automatic recognition of different fracture morphologies, measurements of apparent porosity in three sintered steel specimens are performed The results are related to the bending fatigue limits. Automatic recognition is also used to measure the coarseness of fracture surfaces related to the so-called Jernkontoret Fracture Standard Set Number.
GRAY TONE FILTERING ON ERS-SAR IMAGES APPLIED TO CHANGE DETECTION AND MAPPING
Authors: André Gilles , Hess Sigrid , Mering Catherine
Published: July 2011

In SAR images, the pixel values are tightly related to physical parameters of the soil such as topography, roughness and humidity, regardless to atmospheric conditions. Therefore, SAR images may be used to detect, and quantify changes in land cover, by comparison of time series SAR data. Classical change detection techniques from SAR images are based on additive synthesis of RGB colors and arithmetic operations between images. The noisy aspect of ERS image due to the original speckle is an obstacle for available mapping and quantification of the changes. Here, statistical and morphological filters are used to reduce the speckle noise. Combined techniques of change detection and noise filtering are applied here to assess and map from ERS-SAR images the impact of regular or catastrophic flood and deforestation in the East Coast of Madagascar.
COLOUR IMAGE IN 2D AND 3D MICROSCOPY FOR THE AUTOMATION OF POLLEN RATE MEASUREMENT
Authors: Bonton Pierre , Boucher Alain , Thonnat Monique , Tomczak Regis , Hidalgo Pablo J , Belmonte Jordina , Galan Carmen
Published: July 2011

Pollen monitoring is of great importance for the prevention of allergy. As this activity is still largely carried out by humans, there is an increasing interest in the automation of pollen monitoring. The goal is to reduce monitoring time in order to plan more efficient treatments. In this context, an original device based on computer vision is developed. The goal of such a system is to provide accurate measurement of pollen concentration. This information can be used as well by palynologists, clinicians or by a forecast system to predict pollen dispersion. The system is composed of two modules: pollen grain extraction and pollen grain recognition. In the first module, the pollen grains are observed in light microscopy and are extracted automatically from a microscopic slide dyed with fuchsin and digitised in 3D. The colour segmentation techniques implemented on a hardware architecture are presented. In the second module, the pollen grains are analysed for recognition. To accomplish recognition, it is necessary to work on 3D images and to use deep palynological knowledge. This knowledge describes the pollen types according to their main visible characteristerics and to those which are important for recognition. Some pollen structures are identified, like the pore with annulus in Poaceae, the reticulum in Olea and similar pollen types or the cytoplasm in Cupressaceae. Preliminary results show correct recognition of some pollen types, like Urticaceae or Poaceae, and some groups of pollen types, like reticulate group.
IMPROVING METHODOLOGICAL STRATEGIES FOR SATELLITE CELLS COUNTING IN HUMAN MUSCLE DURING AGEING
Authors: Sajko Špela , Kubínová Lucie , Kreft Marko , Dahmane Raja , Wernig Anton , Eržen Ida
Published: July 2011

Stereological methods, based on the optical disector principle and fluorescent staining, were developed for estimating frequency of satellite cells in skeletal muscles. The parameter NL(sc, fib) (number of satellite cells per fibre length) was compared with the parameter NN(sc, nucl) (the percentage of satellite cell nuclei in all muscle nuclei), most often published in the literature, by applying unbiased sampling and counting procedures and using a confocal microscope. The methods were tested in autopsy samples of four young vs. four old human vastus lateralis muscles. Both parameters NL(sc, fib) and NN(sc, nucl) declined during ageing. However, it appears that the two parameters cannot be substituted one by the other because the number of nuclei per fibre length tends to be increased during aging. Using the introduced methods, it is more straightforward to estimate NL(sc, fib) than NN(sc, nucl).
PHYSICAL AND CHEMICAL CHARACTERIZATION OF NEUROLOGICAL INJURY IN AN AVIAN MODEL OF PRIMARY GENERALIZED EPILEPSY
Authors: Kendall Edward , Gong Zhao , Tuchek John , Obenaus André
Published: July 2011

Purpose This study was undertaken to determine if the epileptic chicken phenotype exhibited unique physical and chemical neurological changes. Methods Quantitative 1H-MRI/MRS measurements were performed on adult control (Rr) and epileptic (rr) chickens. The metrics included nuclear relaxation rate, diffusion rate and concentration of metabolites associated with neuronal cells. Comparisons were performed using Students t or Mann-Whitney tests according to the data distribution. Results Proton density measurements detected no significant difference in density among the cerebral hemispheres and optic lobes within the control and epi birds, nor between bird phenotypes. Thus, within experimental error it appears that brain tissue density is similar in adult control and epi birds. Volume calculation from images spanning the entire brain confirmed that a consistent feature of the epi genotype was megalencephaly. Nuclear relaxation (T2 ) values obtained for the control bird were within the normal variant range for neuronal tissue. However, T2's of the epi birds were significantly higher than that of the controls ((158 ms versus 123 ms). Similarly, in the diffusion data there was no apparent hemispheric bias. The optic lobes of the control animals exhibited an apparent diffusion coefficient significantly lower than that found for the cerebrum (Table 2). Interestingly, this differential was not apparent in the epi birds. The control birds across all regions of interest exhibited an ADC significantly less than that of the epi birds. Quantitative 1Hspectroscopy using tissue extracts collected immediately after sacrifice revealed phenotypic differences in lactate, glutamate, creatine and NAA but not GABA. A reduction in NAA was detected in the cerebrum of epi birds. This is in agreement with the generally held view that seizure activity causes loss of neurones, thus the loss of N-acetyl aspartate. HPLC data corroborated the spectroscopic NAA findings but also detected an increase in GABA concentration in the epileptic birds. Conclusion The physical changes observed are consistent with dilution of the interstitial fluid by edema or through cellular reordering within the epi brain. The concomitant reduction in excitable neuronal cells and the relative increase in GABA observed in biochemical analysis are consistent with a fundamental change in the cellular population.
MORPHOLOGICAL DESCRIPTIONS USING THREE-DIMENSIONAL WAVEFRONTS
Authors: Serra Jean
Published: July 2011

The present study deals with the analysis of three-dimensional binary objects whose structure is not obvious nor generally clearly visible. Our approach is illustrated through three examples taken from biological microscopy. In one of our examples, we need to extract the osteocytes contained in sixty confocal sections. The cells are not numerous, but are characterized by long branches, hence they will be separated using a directional wavefront The two other objects are more complex and will be analysed by means of a spherical wavefront In the first case, a kidney of a rat embryo, the tissue grows like a tree, where we want to detect the branches, their extremities,and their spatial arrangement. The wavefront method enables us to define precisely branches and extremities, and gives flexible algorithms. The last example deals with the embryonic growth of the chicken shinbone. The central part of the bone (or shaft) is structured as a series of nested cylinders following the same axis, and connected by more or less long bridges. Using wavefronts, we show that it is possible to separate the cylinders,and to extract and count the bridges that connect them.
3D IMAGING USING COHERENT SYNCHROTRON RADIATION
Authors: Cloetens Peter , Ludwig Wolfgang , Boller Elodie , Peyrin Françoise , Chlenker Michel , Baruchel Jose
Published: July 2011

Three dimensional imaging is becoming a standard tool for medical, scientific and industrial applications. The use of modem synchrotron radiation sources for monochromatic beam micro-tomography provides several new features. Along with enhanced signal-to-noise ratio and improved spatial resolution, these include the possibility of quantitative measurements, the easy incorporation of special sample environment devices for in-situ experiments, and a simple implementation of phase imaging. These 3D approaches overcome some of the limitations of 2D measurements. They require new tools for image analysis.
ESTIMATING THE INTENSITY OF GERM-GRAIN MODELS WITH OVERLAPPING GRAINS
Authors: Ghorbani Hamid , Stoyan Dietrich
Published: July 2011

Formulas are derived for the spherical contact distribution of a planar germ-grain model Z with circular grains where the germs formeither a 'segment cluster' process or a 'line-based' Poisson point process. They are used in order to estimate the intensityl of the germprocess by means of the spherical contact distribution function. As an application the number of dislocations on a silicon wafer is estimated.
3D SIMULATION STUDY OF INHOMOGENEOUS MICROSTRUCTURE AND ITS EVOLUTION (advantages of visual simulation technique in stereological analysis)
Authors: Song Xiaoyan , Rettenmayr Markus , Liu Guoquan
Published: July 2011

A 3D Monte Carlo technique has been used to simulate a complex process of recrystallization in a material containing precipitates after graded deformation. By the simulation model, the inhomogeneous deformed microstructure and its evolution during subsequent annealing were directly displayed; moreover, the locally varying recrystallized microstructure was quantitatively analyzed. The simulation results were well verified by experiments with an aluminum alloy containing Al3Zr particles that had been subjected to deformation and annealing for recrystallization. In the stereological analysis of a non-random microstructure and its evolution kinetics, the visual simulation technique showed apparent advantages for sampling, detection and measuring.
QUICK DETERMINATION OF CRYSTAL SIZE DISTRIBUTIONS OF ROCKS BY MEANS OF A COLOR SCANNER
Authors: Tarquini Simone , Armienti Pietro
Published: July 2011

An acquisition and analysis method based on a commercial, low-cost, high-resolution film scanner is presented. It allows to collect data from standard rock thin sections with a resolution up to 9.4 μm per pixel. Common and general purpose facilities (scanner + PC + image analysis software) may thus be transformed in an appropriate tool for quantitative textural analysis of rocks. The procedure implies the acquisition of four images with crossed polarizers and one parallel light image. Crystal boundaries are extracted from fields in crossed polarizers, while markers for mineral recognition are obtained thresholding the parallel light image. The method is tested for fresh rocks with simple mineralogy (harzburgites and marbles) with no more than three phases, all exhibiting well distinct optical properties. Image processing is performed developing procedures with VISILOG 5.2 package. 2-D size data from binary images are converted to 3-D size data applying stereological corrections. 3-D data are reported in bi-logarithmic diagrams, plotting the crystal number density versus characteristic lengths. The harzburgite samples show a scale invariance of size distributions of olivine while mosaic equant marbles exhibit a different size distribution pattern, without scale invariance and a relative maximum.
DYNAMIC PARTICLE SYSTEMS FOR OBJECT STRUCTURE EXTRACTION
Authors: Lavialle Olivier , Angella Franck , Germain Christian , Baylou Pierre
Published: July 2011

A new deformable model based on the use of a particle system is introduced. By defining the local behavior of each particle, the system behaves as an active contour model showing a variable topology and regularization properties. The efficiency of the particle system is illustrated by two applications: the first one concerns the use of the system as a skeleton extractor based on the propagation of particles inside a treeshaped object. Using this method, it is possible to generate a cartography of structures such as veins or channels. In a second illustration, the system avoids the problem of initialization of a piecewise cubic Bspline network used to straighten curved text lines.
QUANTIFICATION OF ANGIOGENESIS ON THE RAT AORTIC RING ASSAY
Authors: Blacher Silvia , Devy Laetitia , Noel Agnes , Foidart Jean-Michel
Published: July 2011

Image analysis is used to quantify angiogenesis on the rat aortic ring model. This technique allows to determine: (1) the aortic ring area and factor shape; (2) the number of microvessels, the total number of branching, the maximal microvessel length and the number of microvessels in function of the distance to the aortic ring; (3) the total number of isolated fibroblast-like cells and the number of fibroblast-like cells in function of the distance to the aortic ring. We show that this method is suitable to quantify spontaneous angiogenesis as well as to analyse a complex microvascular network induced by vascular endothelial growth factor (VEGF).
STEREOLOGICAL STUDIES ON FETAL VASCULAR DEVELOPMENT IN HUMAN PLACENTAL VILLI
Authors: Mayhew Terry M
Published: July 2011

In human pregnancy, fetal well-being depends on the development of placental villi and the creation and maintenance of fetal microvessels within them. The aim of this study was to define stereological measures of the growth, capillarization and maturation of villi and of fetoplacental angiogenesis and capillary remodelling. Placentas were collected at 12-41 weeks of gestation and assigned to six age groups spanning equal age ranges. Tissue samples were randomised for position and orientation. Overall growth of peripheral (intermediate and terminal) villi and their capillaries was evaluated using total volumes, surface areas and lengths. Measures of villous capillarization comprised capillary volume, surface and length densities and capillary:villus surface and length ratios. Size and shape remodelling of villi and capillaries was assessed using mean cross-sectional areas, perimeters and shape coefficients (perimeter2/area). Group comparisons were drawn by analysis of variance. Villous and capillary volumes, surfaces and lengths increased significantly throughout gestation. Villous maturation involved phasic (capillary:villus surface and length ratios) or progressive (volume, surface and length densities) increases in indices of villous capillarization. It also involved isomorphic thinning (cross-sectional areas and perimeters declined but shape coefficients did not alter). In contrast, growth of capillaries did not involve changes in luminal areas or perimeters. The results show that villous growth and fetal angiogenesis involve increases in overall length rather than calibre and that villous differentiation involves increased capillarization. Although they do not distinguish between increases in the lengths versus numbers of capillary segments, other studies have shown that capillaries switch from branching to non-branching angiogenesis during gestation. Combined with maintenance of capillary calibres, these processes will contribute to the reduced fetal vascular impedances observed during pregnancy.
PLASTICITY OF SKELETAL MUSCLE STUDIED BY STEREOLOGY
Authors: Eržen Ida
Published: July 2011

The present contribution provides an overview of stereological methods applied in the skeletal muscle research at the Institute of Anatomy of the Medical Faculty in Ljubljana. Interested in skeletal muscle plasticity we studied three different topics: (i) expression of myosin heavy chain isoforms in slow and fast muscles under experimental conditions, (ii) frequency of satellite cells in young and old human and rat muscles and (iii) capillary supply of rat fast and slow muscles. We analysed the expression of myosin heavy chain isoforms within slow rat soleus and fast extensor digitorum longus muscles after (i) homotopic and heterotopic transplantation of both muscles, (ii) low frequency electrical stimulation of the fast muscle and (iii) transposition of the fast nerve to the slow muscle. The models applied were able to turn the fast muscle into a completely slow muscle, but not vice versa. One of the indicators for the regenerative potential of skeletal muscles is its satellite cell pool. The estimated parameters, number of satellite cells per unit fibre length, corrected to the reference sarcomere length (Nsc/Lfib) and number of satellite cells per number of nuclei (myonuclei and satellite cell nuclei) (Nsc/Nnucl) indicated that the frequency of M-cadherin stained satellite cells declines in healthy old human and rat muscles compared to young muscles. To access differences in capillary densities among slow and fast muscles and slow and fast muscle fibres, we have introduced Slicer and Fakir methods, and tested them on predominantly slow and fast rat muscles. Discussing three different topics that require different approach, the present paper reflects the three decades of the development of stereological methods: 2D analysis by simple point counting in the 70's, the disector in the 80's and virtual spatial probes in the 90's. In all methods the interactive computer assisted approach was utilised.
CYTOKINESIS-BLOCK MICRONUCLEUS ASSAY IN HUMAN GLIOMA CELLS EXPOSED TO RADIATION
Authors: Slowinski Jerzy , Bierzynska-Macyszyn Grazyna , Mazurek Urszula , Widel Maria , Latocha Malgorzata , Stomal Monika , Snietura Miroslaw , Mrowka Ryszard
Published: July 2011

Biological tests are efficient in reflecting the biological influences of several types of generally harmful exposures. The micronucleus assay is widely used in genotoxicity studies or studies on genomic damage in general. We present methodological aspects of cytokinesis-block micronucleus assay performed in human gliomas irradiated in vitro. Eight human glioblastoma cell lines obtained from DSMZ (Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH, Germany) were gamma-irradiated (60Co) over a dose range of 0-10 Gy. Cytokinesis-block micronucleus assay was performed to quantitate cytogenetic damage. The cells were fixed directly on dishes, stained with fluorochrome DAPI and evaluated under fluorescent and phase contrast microscope. The micronucleus frequency was expressed as a micronuclei (MN) per binucleated cell (BNC) ratio, calculated after scoring at least 100 BNC per dish. The frequency of spontaneous MN ranged from 0.17 to 0.613 (mean: 0.29 ± 0.14). After irradiation increase of MN frequency in the range of 0.312 - 2.241 (mean: 0.98 ± 0.68) was found at 10 Gy. Gliomas are extremely heterogenous in regard to cytogenetic effects of irradiation, as shown in this study by cytokinesis-block micronucleus assay. This test is easily performed on irradiated glioma cell lines and can assist in determining their radiosensitivity. However, in order to obtain reliable and reproducible results, precise criteria for MN scoring must be strictly followed. Simultaneous use of fluorescent and phase contrast equipment improves imaging of morphological details and can further optimize MN scoring.
REVIEW OF RECENT DEVELOPMENTS IN CONE-BEAM CT RECONSTRUCTION ALGORITHMS FOR LONG-OBJECT PROBLEM
Authors: Zeng Kai , Chen Zhiqiang
Published: July 2011

Long-object problem and short-object problem both deal with reconstruction problems with truncated conebeam CT projections acquired with a helical path. They have significantly less practical limitations than original exact cone-beam CT reconstruction algorithms which the cone-beam must cover the whole object. The short-object problem can be defined as reconstruction of the whole object having a finite support in the axial direction with helical scan extends a little bit above and below the object's support. However the longobject problem is to reconstruct the central region of interest (ROI) of a long object having an infinite support in the axial direction with helical scan extends a little a bit above and below the ROI. Although the short-object problem is more difficult to solve than the conventional exact reconstruction with non-truncated projections, the long-object problem presents greater challenge to researchers. Recently, with the great development of panel detector technology and computer technology, more and more researchers have been inspired to work on it. Because of great practical value of long-object algorithms, this paper focuses on the review and discussion of recent developments in long-object algorithms. All Long-object algorithms are classified as exact and approximate algorithms. After going briefly over the history of cone-beam algorithms, some novel cone-beam long-object algorithms are introduced, such as: Tam's algorithm, PImethod, PHI-method, etc. Then, the methods described are being compared and discussed.
A MICROSTRUCTURAL MODEL BY SPACE TESSELLATION FOR A SINTERED CERAMIC: CERINE
Authors: Coster Michel , Arnould Xavier , Chermant Jean-Louis , Moataz Abder El , Chartier Thierry
Published: July 2011

This paper deals with the use of probabilistic models such as Voronoi tessellation and the Johnson-Mehl model to simulate microstructures of monophased materials. Sintered cerine was chosen to test the various models. The values of morphological parameters measured, both on such models and real microstructures are in very good agreement. An extension for porous materials is also presented. This work shows that the probabilistic models are very well suited for the simulation and description of ceramic and granular microstructures.
ESTIMATING THE SECTION ELEVATION ANGLE OF CUBES ON A CUBIC MESH. APPLICATION TO NICKEL MICROSTRUCTURE SIZE ESTIMATION
Authors: Germain Christian , Blanc Rémy , Donias Marc , Lavialle Olivier , Costa Jean-Pierre Da , Baylou Pierre
Published: July 2011

This paper discusses two new image analysis methods for estimating the elevation angle of the section plane of a material. These methods are applicable to materials such as nickel base superalloys, the microstructure of which shows cubes arranged on a cubic regular grid. 3-D models were proposed that help interpret the section images and validate our approach. Our first method operates in the Fourier domain, and is based on the estimation of the spatial frequencies of the network of lines observed on the section. The second method is based on the average distance measured between hazy areas. Both methods are independent. Applied to synthetic images or to real material samples, they produce comparable estimations. The values of the elevation angle allow us to cancel the bias associated with the estimation of the material pattern dimensions.
A CASE STUDY ON POINT PROCESS MODELLING IN DISEASE MAPPING
Authors: Beneš Viktor , Bodlák Karel , Møller Jesper , Waagepetersen Rasmus
Published: July 2011

We consider a data set of locations where people in Central Bohemia have been infected by tick-borne encephalitis (TBE), and where population census data and covariates concerning vegetation and altitude are available. The aims are to estimate the risk map of the disease and to study the dependence of the risk on the covariates. Instead of using the common area level approaches we base the analysis on a Bayesian approach for a log Gaussian Cox point process with covariates. Posterior characteristics for a discretized version of the log Gaussian Cox process are computed using Markov chain Monte Carlo methods. A particular problem which is thoroughly discussed is to determine a model for the background population density. The risk map shows a clear dependency with the population intensity models and the basic model which is adopted for the population intensity determines what covariates influence the risk of TBE. Model validation is based on the posterior predictive distribution of various summary statistics.
CAPILLARY NETWORK IN SLOW AND FAST MUSCLES AND IN OXIDATIVE AND GLYCOLYTIC MUSCLE FIBRES
Authors: Čebašek Vita , Kubínová Lucie , Ribarič Samo , Eržen Ida
Published: July 2011

The aim of this study was to compare capillary network in slow and fast muscles and also in oxidative and glycolytic muscle fibres. Soleus (SOL) and extensor digitorum longus (EDL) muscles were excised from five female rats. Capillaries and muscle fibres were demonstrated on thick tissue sections by a triple immunofluorescent method. Stacks of perfectly registered optical images were captured by a confocal microscope and further analysed. Applying stereological methods (POINTGRID, FAKIR and SLICER plugin- modules of the Ellipse programme), we estimated the mean length of capillaries, adjacent to individual muscle fibre, per unit fibre length (Lcap/Lfib), per unit surface area of the fibre (Lcap/Sfib) and per unit fibre volume (Lcap/Vfib) in the slow SOL and in predominantly fast EDL muscle, and separately in oxidative and glycolytic fibres of EDL muscle. The length of capillaries per unit fibre length was larger in SOL than in EDL muscle, however, capillary length per unit fibre volume was larger in EDL muscle. There was no difference in the length of capillaries per unit fibre surface area between the two muscles. Oxidative and glycolytic fibres differ in the length of capillaries per unit fibre surface area (Lcap/Sfib). This parameter probably reflects the oxidative capacity of muscle fibres. In conclusion, capillary supply is evidently well adapted to different muscle fibre types; consequently, an average capillary supply of a heterogeneous muscle depends on the muscle composition. The estimated mean values blur some intrinsic differences.
SYSTEMIC KANAMYCIN TREATMENT HAS NO EFFECT ON CELL NUMBERS IN THE MOUSE UTRICULAR MACULA
Authors: Kirkegaard Mette , Severinsen Stig Å , Wogensen Lise , Nyengaard Jens R
Published: July 2011

The aim of the present study is to estimate the total number of the sensory hair cells (chalice innervated and bouton innervated) and supporting cells in the mouse utricular sensory epithelium at two different time points after systemic kanamycin treatment. Mice were given two daily subcutaneous injections of kanamycin (600 or 900 mg/kg) for 15 consecutive days and allowed to survive either 1 or 3 weeks after end of treatment. Cell numbers were estimated using a physical fractionator. Paraffin-embedded tissue was immunohistochemically stained for active caspase-3 in order to detect apoptosis. There was no change in hair cell or supporting cell number after treatment with kanamycin and the survival time had no effect. Although no positive staining for caspase-3 was seen, hair cells with swollen chalices and dark stained nuclei were observed in the sensory epithelium of the treated animals, indicating some effect of the treatment. In conclusion, the dosing regime and survival times studied here are not sufficient to induce hair cell loss in the mouse utricle.
BAYESIAN IMAGE RESTORATION, USING CONFIGURATIONS
Authors: Thorarinsdottir Thordis Linda
Published: July 2011

In this paper, we develop a Bayesian procedure for removing noise from images that can be viewed as noisy realisations of random sets in the plane. The procedure utilises recent advances in configuration theory for noise free random sets, where the probabilities of observing the different boundary configurations are expressed in terms of the mean normal measure of the random set. These probabilities are used as prior probabilities in a Bayesian image restoration approach. Estimation of the remaining parameters in the model is outlined for salt and pepper noise. The inference in the model is discussed in detail for 3 X 3 and 5 X 5 configurations and examples of the performance of the procedure are given.
EVALUATION OF BONE-TO-IMPLANT CONTACT AND BONE DENSITY ADJACENT TO TITANIUM IMPLANTS USING A STEREOLOGICAL TECHNIQUE ON GROUND SECTIONS
Authors: Balatsouka Dimitra , Gotfredsen Klaus , Gundersen Hans Jørgen G
Published: July 2011

When bone implants have to be examined in situ ground sections are required. Histomorphometric measurements are usually performed on two-dimensional sections, causing biased results when they are wrongly extrapolated to 3D without any knowledge of stereology. Unbiased results can only be obtained using stereological principles. The aim of the study was to describe an unbiased design for evaluating boneto-mplant contact (BIC) and peri-implant bone density (BD-i) in three-dimensions. The unbiased design was based on a fixed axis vertical random sampling technique. Three bone-implant blocks were collected from 3 rabbits. Four sections were obtained from each animal using a fixed axis vertical random sampling technique. The BIC was estimated by creating a stereological method based on a systematic test line set. The BD-i was estimated using a design based on a systematic point set. The efficiency of the systematic sampling was evaluated for each sampling level: Coefficient of error CE( i w ) for the systematic test line set, CESyst between the 4 rotated sections, CENoise for the reproducibility. These variances were compared to the biological variation (CV) between animals. The mean CE( i w ) was 5 to 6%; the CESyst was 7.8% for the BIC estimates and 5.7% for the BD-i estimates; the CENoise was 5.8% for the BIC and 7.7% for the BD-i. The CV was 19% for the BIC estimates and 24% for the BD-i estimates. These results demonstrated that the stereological technique used in the present study was a very efficient method to obtain unbiased estimates of BIC and BD-i in 3D on 2D implant-bone sections.