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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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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