WSEAS CONFERENCES. WSEAS, Unifying the Science

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 Volume 8,  2011
Print ISSN: 1109-9518
E-ISSN: 2224-2902








Issue 1, Volume 8, January 2011

Title of the Paper: Bradykinin B1 Receptor Overexpression is Positively Correlated with Increased Histidine Decarboxylase (HDC) Activity – A Potential Role in the Pathophysiology of Diabetic Placenta


Authors: Dariusz Szukiewicz, Michal Pyzlak, Habib Alkhalayla, Arlena Szukiewicz, Slawomir Maslinski

Abstract: Hyperhistaminaemia and increased bradykinin have been found in diabetic placentae. Both, histamine and bradykinin are well known mediators of inflammation. Bradykinin may stimulate mast cell degranulation, increasing the local histamine level. Bradykinin B1 receptor shows involvement in the inflammatory response, whereas the B2 receptor mediates most of the effects induced by kinins. In this study we examined comparatively (diabetes class C vs normal pregnancy) correlations between placental HDC activity, histamine concentration, and placental bradykinin receptors B1 and B2 expression. Sixteen diabetic placentae and 16 normal (control) placentae were collected (Group I and II, respectively). Activity of HDC was assayed in placental samples obtained in a standardized manner, using a modified method of Endo. Histamine concentrations in placental cuts were estimated fluorimetrically, whereas expression of B1 and B2 was examined in immunostained paraffin sections, using quantitative morphometry in the areas matched in mean vascular density. Mean HDC activity in diabetic placenta was significantly (p<0.05) increased compared to controls (3.97 ?0.25 vs 2.88 ?0.15 nmol/h/g ?SEM). Histamine concentration was also significantly increased in diabetes (387 ?25.3 vs 239 ?14.3 ng/g of wet weight ?SEM; Group I and Group II, respectively). Mean expression of the B1 was augmented in diabetes and reached 289.8% of the value observed for Group II (p<0.05). Mean expression of B2 receptors was similar in both studied groups. Increased HDC activity may be responsible for some of the pathophysiologic events observed in diabetic materno-placento-fetal compartment. HDC-dependent histamine elevation may change locally vascular properties by influence on bradykinin receptors expression. Proinflammatory changes mediated via B1 should be expected rather, than modified vasomotor reactivity related to B2. Angiogenic properties of histamine and kinins may also be of great importance hin diabetic placental tissue.

Keywords: Histidine decarboxylase, histamine, bradykinin receptors, human placenta, diabetes class C, pregnancy

Title of the Paper: Computer Assisted Automatic Sleep Scoring System Using Relative Wavelet Energy Based Neuro Fuzzy Model


Authors: Girisha Garg, Vijander Singh, J. R. P Gupta, A. P. Mittal, Sushil Chandra

Abstract: This paper addresses the automated scoring of sleep stages using Electroencephalograph (EEG). The change in the Sleep Stages is accompanied by changes in the frequency spectrum of the EEG signals. A novel method based on Relative Wavelet Energy based Neuro-fuzzy is proposed to perform automatic sleep stages classification. Features extracted from 30-second epoch of (EEG) using relative wavelet energy are used for representing the EEG signal of different sleep stages. This method gives the best feature vector in terms of specificity and dimension. A neuro-fuzzy based ANFIS model is employed to classify these features to one appropriate stage. The sleep scoring is done for five stages namely, wake, sleep stages: stage1, stage 2, slow wave sleep (stage 3 & 4) and stage 5.The physionet database is used to validate the accuracy of the proposed automatic classification system. The hypnogram generated is compared with the standard hypnogram based on expert rule. The system can be used for real time implementation owing to high classification rate (97.4%), low computational cost, high speed and its feasibility to be implemented on hardware. The result of the study provides a framework of methodology that can be used to design computer assisted sleep scoring systems.

Keywords: Automated Sleep Scoring, hypnogram, EEG, Relative Wavelet energy, ANFIS, Physionet

Title of the Paper: A Different Approach of the Manufacturing Method used to Demonstrate the Effect of Halogenated Organic Compounds and Aromatic Hydrocarbons to the Composite Teeth Denture Base Resin Tensile Strength


Authors: Adelina Elena Stoia, Anca Tudor, Bandur Gheza

Abstract: The evaluation of the efficiency of the organic compounds used in this study, to the composite teeth denture base resin tensile strength represents the main purpose of this study. For this reason 50 large size artificial composite molars (Ivoclar-Vivadent) were used to mille 50 composite cylinders. The cylinders were randomly assigned in five experimental groups, so that 10(ten) cylinders were part of the each one of the 5 experimental groups. The flat milled surfaces of the cylinders, representing the bonding areas were submitted to a different treatment. Group 1:(control group), Group 2: Methylene chloride, Group 3: Ethylene chloride, Group 4: Benzene Group 5: Toluene. The chemical treatment procedures were realized using organic solvents with 98, 9% chemical purity. Self-cured denture base repair resin (Duracryl – Spofa Dental) was used for the bonding test specimens manufacturing, according to the ADA specification No. 15. Each specimen was stored for 30 days in distilled water and tensile tested at a speed of 1 mm/min. The mean values of the tensile bond strength test registered were statistically significant among groups, ranging from 13, 41 MPa (group 2) to 25,70 MPa ( group 1). The results of this study suggest the fact that the chemical treatment with the organic solvents mentioned above generates not a statistically significant improvement to the adhesion of the composite teeth to the denture base resin.

Keywords: Benzene, composite teeth, denture base resin, ethylene chloride, metlylene chloride, polymers, tensile strength, toluene

Issue 2, Volume 8, April 2011

Title of the Paper: Extracted Haralick’s Texture Features and Morphological Parameters from Segmented Multispectrale Texture Bio-Images for Classification of Colon Cancer Cells


Authors: Ahmad Chaddad, Camel Tanougast, Abbas Dandache, Ahmed Bouridane

Abstract: The automatic recognition and classification of biomedical objects can enhance work efficiency while identifying new inter-relationships among biological features. In this paper two features types, Haralick’s features based GLCM are applied for classification of cancer cell of textured images and morphological parameters based of cells detection. The objective in our work is the selection of the most discriminating parameters for cancer cells classification. In this work, a new approach aiming to detect and classify colon cancer cells is presented. Our detection approach was derived from the "Snake" method but using a progressive division of the dimensions of the image to achieve faster segmentation. Classification of three cell types was based on nine morphological parameters and five Haralick’s features on probabilistic neural network. Three morphological parameters and three Haralick’s features were used to assess the efficiency classifications models, including Benign Hyperplasia (BH), Intraepithelial Neoplasia (IN) that is a precursor state for cancer, and Carcinoma (Ca) that corresponds to abnormal tissue proliferation (cancer). Results showed that segmentation of microscopic images using this technique was of higher efficiency than the conventional Snake method. The time consumed during segmentation was decreased to more than 50%. The efficiency of this method resides in its ability to segment Ca type cells that was difficult through other segmentation procedures. Among the nine parameters morphology and five Haralick’s features used to classify cells, only three morphologic parameters (Area, Xor convex and Solidity) and three Haralick’s features (Correlation, Entropy and Contrast) were found to be effective to discriminate between the three types of cells. In addition, classification of unknown cells was possible using the morphology method. However, some IN cells were wrongly classified as BH cells due to their shapes that were similar to those of BH cells. On the other side, the classification based on three parameters (Correlation, Entropy and Contrast) were found to be effective to discriminate between the three types of cells without wrong. The results obtained using several images show the efficacy of our proposed method.

Keywords: GLCM, Haralick’s features, Morphologic parameters, Segmentation, Snake, Classification

Title of the Paper: Ultrasound Images Edge Detection using Anisotropic Diffusion in Canny Edge Detector Framework


Authors: Hum Yan Chai, Lai Khin Wee, Eko Supriyanto

Abstract: Conventional Canny edge detector can detect edges in image with additive noise effectively but not ultrasound image that are corrupted by multiplicative speckle noise which alleviates image resolution resulting in inaccurate characterization of object features. In this paper, we proposed to incorporate the modified SRAD into the Canny edge detector to replace the Gaussian blurring in the conventional Canny edge detector in order to suppress the multiplicative noise effectively while preserving the edge of the object in ultrasound image. The result shows that the proposed method can provide better result than conventional method in a much wider range of parameter values. The proposed method through experimental result indicates that it is capable of producing promising edge detection result in ultrasound image.

Keywords: Edge detection, speckle reducing anisotropic diffusion, ultrasound image enhancement, noise filtering

Title of the Paper: Prostate Tumor Segmentation for Gamma Image Using Region Growing Approaches


Authors: Lai Khin Wee, Eko Supriyanto, Yeoh Jing Wui, Nuraini Md Isa, Bustanur Rosidi

Abstract: Prostate is a gland of male reproductive system to store semen. The prostate cancer is prevalent among the male which may cause mortality. It is usually unpredictable in the clinical course as the prostate cancer mostly slows grow and do not manifest in the early stage. Recent imaging technique is usually focused on the local or regional imaging so that the tumor can be more precisely identified. The measurement of tumor size can be used to inspect the progress of the severity. Gamma imaging that employs the radiotracer is widely used in the imaging of prostate cancer. However, the imaging technique is still unable to show clearly the edge of the tumor where it may cause wrong diagnosis and wrong measurement of the tumor size. Therefore, in order to increase the image quality, Gabor filter is used to reduce the noise of the image and to smooth the image. Segmentation with region growing method will be implemented to subdivide the image into the region of interest (tumor) to facilitate the radiologist in identifying and measuring the tumor size to make a more precise decision in provision of appropriate therapy. This technique is verified by five other images with prostate cancer from different modalities in radiology. The results show that the tumor can be accurately partitioned alone from the surrounding normal tissues by varying the intensity range. However, there are some cases cannot really isolate the tumor alone but it still can show clearly the tumor shape and edge. Hence, it can be concluded that this technique is valid to be applied in the clinical field to assist in the interpretation process.

Keywords: Prostate cancer, gamma imaging, Gabor filter, region growing segmentation

Issue 3, Volume 8, July 2011

Title of the Paper: Ecoepidemics with Two Strains: Diseased Predators


Authors: Fabio Roman, Federica Rossotto, Ezio Venturino

Abstract: In this paper we present the first ecoepidemic model containing two disease strains in the same population, specifically in the predators. We present two models, in the first one of which the epidemics is transmitted only horizontally. The second one is more general, since it allows also vertical transmission of the disease, i.e. offsprings of infected parents also carry the disease. Answers to relevant biological questions are analysed. Surprisingly, however, this ecoepidemic system with two strains cannot be sustained at a stable coexistence equilibrium level.

Keywords: Epidemics, Population Models, Ecoepidemics, Two-Strain Models, Equilibria, Stability

Title of the Paper: Large Eddy Simulation of Stenotic Flow forWall Shear Stress Estimation - Validation and Application


Authors: Roland Gardhagen, Jonas Lantz, Fredric Carlsson, Matts Karlsson

Abstract: Turbulent flow in the cardiovascular system may increase the risk for severe arterial disease. This work addresses the feasibility of Large Eddy Simulation (LES) using a general purpose code as a tool for assessment of cardiovascular flow and investigates Wall Shear Stress (WSS) in steady as well as pulsating turbulent pipe flow. Poiseuille flow was specified at the inlet, and with a suitable ammount of perturbations at the inlet it was possible to predict experimental data. The extent of the recirculation zone was affected by the inlet disturbances, and magnitude as well as direction of the WSS vector varied significantly at the reattachment point. For the pulsating flow, WSS shows a complex pattern with different spatial and temporal variation along the pipe. Thewall shear stress gradient was calculated on the entire post-stenotic surface and each component in the gradient was investigated. The off-diagonal components in the gradient are usually assumed to be small, but here they were found to be on the same order of magnitude as the diagonal terms. This work demonstrates the need for a scale resolving simulation technique to accurately model cardiovascular flows.

Keywords: Turbulence, Large Eddy Simulation, Cardiovascular Flow, Wall Shear Stress

Title of the Paper: Computerized Anisotropic Diffusion of Two Dimensional Ultrasonic Images using Multi-Direction Spreading Approaches


Authors: Lai Khin Wee, Hum Yan Chai, Eko Supriyanto

Abstract: Ultrasound medical imaging is widely used nowadays in clinical application due to its intuitive, convenient, safety, non-invasive, and low cost. However, ultrasound image formation always comes with speckle-noise which will greatly reduce the image quality, and makes the identification and analysis of image detail become more challenging. Hence, we present an extended robust diffusion algorithm for optimum diffusion while retain the edge of image features. Total eight spreading diffusion directions are implemented in the proposed algorithm. Finding showed that this method is able to provide consistent and more objective results.

Keywords: Ultrasound, diffusion, two dimensional, imaging, speckle, noise, filter, spreading, anisotropic

Issue 4, Volume 8, October 2011

Title of the Paper: Population Biology Models with Time-Delay in a Noisy Environment


Authors: Andre A. Keller

Abstract: This article initiates the ecological modeling process in population biology and is centered on the well-known Lotka-Volterra multispecies system. In these models populations interact, fight or cooperate, in real life conditions: such as with constant time-delays in a noisy environment. The illustrative systems are the epidemic models and the predator-prey model with possibly overcrowding. The Euler-Maruyama approximation method is used to solve nonlinear stochastic delay differential equations. The probability density function of the solutions is estimated via the Fokker-Planck equation. Appendices with examples and references are proposed to the users. The computations have been carried out with help of two mathematical software: MATLAB® 7.12 R2011a and Wolfram MATHEMATICA ® 8.

Keywords: Diffusion model, Predator-prey model, Overcrowding, Stochastic delay differential equation, Euler-Maruyama method, Forward Kolmogorov equation, Fokker-Planck equation, Stratonovich calculus, Ito formulation.

Title of the Paper: Optimization of Pancreas Measurement Techniques Based on Ultrasound Images


Authors: Wan Mahani Hafizah, Wong Wei Yun, Eko Supriyanto

Abstract: Ultrasound imaging can be used in evaluating the acute pancreatitis, which often shows an enlarged pancreas as well as in detecting the diabetes mellitus, which the pancreas is smaller compared to normal size. Besides, these imaging techniques can be used in detecting stones in the bile duct and help in assessing the pancreatic parenchyma directly. This study proposes an approach for optimizing the pancreas measurement technique based on ultrasound images consists of image enhancement as well as image segmentation. For image enhancement, four techniques have been compared by calculating the MSE and PSNR of the output image. Level sets method has been applied for segmentation the pancreas after enhancement. This was to enable the higher accuracy of pancreas size measurement. Measurement results show that median filter gives the lowest value of MSE and highest value of PSNR compared to frequency domain Gaussian low-pass filter, histogram equalization and wavelet filter. We found that the pancreas size of Malaysian population is 8.5 ± 1.5 cm in length.

Keywords: Pancreatic disease, acute pancreatitis, median filter, wavelet filter, pancreas size

Title of the Paper: Computational Techniques and Validation of Blood Flow Simulation


Authors: Luisa Sousa, Catarina Castro, Carlos Antonio, Rui Chaves

Abstract: Plaque formation leading to stenosis and occlusion of arterial blood vessels causes altered flow conditions, such as separation and flow-reversal zones and plays an important role in the development of arterial diseases. Computational simulations of blood flow can help to understand the hemodynamics in blood vessels and to predict the outcomes of surgeries. The paper presents a three dimensional numerical method of steady and pulsatile blood flow simulation in arteries by the finite element method. In this study the biochemical and mechanical interactions between blood and vascular tissue are neglected and no-slip boundary conditions are considered at the artery wall. Velocity field is calculated by a mixed method using a smoothed deviatoric stress field in order to obtain an improvement of the finite element method performance. Stabilized finite element formulations to properly treat incompressible and high Reynolds number flows are presented. Velocity and wall shear stress fields are visualized for a better understanding of flow characteristics such as distributions of the flow pattern, stagnation flow and recirculation zones. Simulated results are compared and validated with literature data obtained from ultrasound measurements.

Keywords: Blood flow, Finite Element Method, mixed methods, upwinding techniques

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