Sokratis Makrogiannis | Delaware State University-USA (original) (raw)

Papers by Sokratis Makrogiannis

Research paper thumbnail of A Synergistic Model for Monitoring Brain's Changes: A Case Study

2011 IEEE 23rd International Conference on Tools with Artificial Intelligence, 2011

It is known that the early detection of chronic diseases significantly increases the life span of... more It is known that the early detection of chronic diseases significantly increases the life span of the elderly and improves the quality of life in general. Since the brain is the most valuable part of the human body, it is very important for the physicians to know the stages of aging and changes that take place during these stages and

Research paper thumbnail of A Neural Network-Based Detection of Bleeding in Sequences of WCE Images

Fifth IEEE Symposium on Bioinformatics and Bioengineering (BIBE'05), 2005

ABSTRACT This paper deals with development of a methodology for detecting bleeding in WCE images.... more ABSTRACT This paper deals with development of a methodology for detecting bleeding in WCE images. The presented methodology is based on a neural net model available in the AIIS Inc. and the results of this methods were tested at the AT research lab. The performance of our method offers promising results in comparison with the ones made by the given imaging RBIS (red blood identification system), which vary from 21% to 41%. Our method is under improvements and the expected results will reach near 80% or more.

Research paper thumbnail of Scale space segmentation of color images using watersheds and fuzzy region merging

Proceedings 2001 International Conference on Image Processing (Cat. No.01CH37205), 2001

Research paper thumbnail of Color image edge detection based on nonparametric density estimation

Proceedings 2001 International Conference on Image Processing (Cat. No.01CH37205), 2001

Abstract A novel computationally efficient adaptive algorithm to accomplish edge detection in mul... more Abstract A novel computationally efficient adaptive algorithm to accomplish edge detection in multidimensional and color images is presented. It is a statistical approach, based on local, non-parametric kernel density estimation. The location of the edge discontinuity ...

Research paper thumbnail of Metabolic abnormalities and hypoleptinemia in α-synuclein A53T mutant mice

Parkinson&amp... more Parkinson's disease (PD) patients frequently display loss of body fat mass and increased energy expenditure, and several studies have outlined a relationship between these metabolic abnormalities and disease severity, yet energy metabolism is largely unstudied in mouse models of PD. Here we characterize metabolic and physiologic responses to a high calorie diet (HCD) in mice expressing in neurons a mutant form of human α-synuclein (A53T) that causes dominantly inherited familial forms of the disease. A53T (SNCA) and wild type (WT) littermate mice were placed on a HCD for 12 weeks and evaluated for weight gain, food intake, body fat, blood plasma leptin, hunger, glucose tolerance, and energy expenditure. Results were compared with both SNCA and WT mice on a control diet. Despite consuming similar amounts of food, WT mice gained up to 66% of their original body weight on a HCD, whereas SNCA mice gained only 17%. Further, after 12 weeks on a HCD, magnetic resonance imaging analysis revealed that WT mice had significantly greater total and visceral body fat compared with SNCA mice (p < 0.007). At the age of 24 weeks SNCA mice displayed significantly increased hunger compared with WT (p < 0.03). At the age of 36 weeks, SNCA mice displayed significant hypoleptinemia compared with WT, both on a normal diet and a HCD (p < 0.03). The HCD induced insulin insensitivity in WT, but not SNCA mice, as indicated by an oral glucose tolerance test. Finally, SNCA mice displayed greater energy expenditure compared with WT, as measured in a Comprehensive Laboratory Animal Monitoring System, after 12 weeks on a HCD. Thus, SNCA mice are resistant to HCD-induced obesity and insulin resistance and display reduced body fat, increased hunger, hypoleptinemia and increased energy expenditure. Our findings reveal a profile of metabolic dysfunction in a mouse model of PD that is similar to that of human PD patients, thus providing evidence that α-synuclein pathology is sufficient to drive such metabolic abnormalities and providing an animal model for discovery of the underlying mechanisms and potential therapeutic interventions.

Research paper thumbnail of Towards segmentation of the thymus in fat and water parametric MR images

Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference, 2011

The thymus, an organ responsible for the development, selection, and maintenance of the periphera... more The thymus, an organ responsible for the development, selection, and maintenance of the peripheral T-cell population, is an important regulator of the immune system. Despite its physiological significance, it has received little attention in the medical image analysis literature. In practice, the anatomical location and variable shape of this gland pose challenges both in the image acquisition and analysis processes. We present an automated method for segmenting the thymus from water and fat parametric MR images that permits further analysis of volumetrics and tissue characterization. We compute fat ratio and water ratio parametric images and introduce the use of a stochastic edge detector that is embedded in a geometric variational segmentation model. Validation experiments of the proposed algorithm against manual delineations of the thymus indicate the applicability of our approach.

Research paper thumbnail of Localization Scale Selection for Scale-Space Segmentation

Lecture Notes in Computer Science, 2005

ABSTRACT In this work the relation between scale-space image segmentation and selection of the lo... more ABSTRACT In this work the relation between scale-space image segmentation and selection of the localization scale is examined first, and a scale selection approach is consequently proposed in the segmentation context. Considering the segmentation part, gradient watersheds are applied to the non-linear scale-space domain followed by a grouping operation. A report on localization scale selection techniques is carried out next. Furthermore a scale selection method that originates from the evolution of the probability distribution of a region uniformity measure through the generated scales is proposed. The introduced algorithm is finally compared to a previously published approach that is also introduced into the segmentation context to indicate its efficacy.

Research paper thumbnail of SEGMENTATION OF COLOR IMAGES USING A HIERARCHICAL FUZZY REGION MERGING

Research paper thumbnail of Understanding Hand Gestures Using Approximate Graph Matching....... BW Miners, OA Basir, and MS Kamel 239 On Comparing Bills of Materials: A Similarity/Distance Measure for Unordered Trees... CJ Romanowski and R. Nagi 249 Intelligent Image Prefetching for Supporting Radiologists’ Primary Reading:...

Research paper thumbnail of Recognition of Merged Characters Based on Forepart Prediction, Necessity-Sufficiency Matching, and Character-Adaptive Masking..................................................... J. Song, Z. Li, MR Lyu, and S. Cai 2 A Brain-Like Neural Network for Periodicity Analysis............. K. Voutsas, G. ...

Research paper thumbnail of Self-Configuring Scheduling Protocol for Ultrasonic Sensor Systems............ S. Srinivasan and A. Pandharipande 2517 Novel Wavelet-mFCM Algorithm for Environmental Sensor Drift Correction................................... R. Dutta 2519 Planar Optical Waveguide Platform for Gas Sensing Using Li...

Research paper thumbnail of A Generic Retrieval Method using Perceptual Color Space and Local Density Estimation

Research paper thumbnail of Special Issue on Algorithms and Tools for Bioinformatics and Bioengineering

Research paper thumbnail of NEURAL NETWORK APPROACH FOR IMAGE CHROMATIC ADAPTATION FOR SKIN COLOR DETECTION

International Journal of Neural Systems, 2007

The goal of image chromatic adaptation is to remove the effect of illumination and to obtain colo... more The goal of image chromatic adaptation is to remove the effect of illumination and to obtain color data that reflects precisely the physical contents of the scene. We present in this paper an approach to image chromatic adaptation using Neural Networks (NN) with application for detecting--adapting human skin color. The NN is trained on randomly chosen color images containing human subject under various illuminating conditions, thereby enabling the model to dynamically adapt to the changing illumination conditions. The proposed network predicts directly the illuminant estimate in the image so as to adapt to human skin color. The comparison of our method with Gray World, White Patch and NN on White Patch methods for skin color stabilization is presented. The skin regions in the NN stabilized images are successfully detected using a computationally inexpensive thresholding operation. We also present results on detecting skin regions on a data set of test images. The results are promising and suggest a new approach for adapting human skin color using neural networks.

Research paper thumbnail of Image chromatic adaptation using ANNs for skin color adaptation

16th IEEE International Conference on Tools with Artificial Intelligence, 2004

Research paper thumbnail of A survey of skin-color modeling and detection methods

Pattern Recognition, 2007

Research paper thumbnail of Watershed-based multiscale segmentation method for color images using automated scale selection

Journal of Electronic Imaging, 2005

Research paper thumbnail of Region oriented compression of color images using fuzzy inference and fast merging

Pattern Recognition, 2002

A new region based lossy compression scheme for color images is proposed. The segmentation method... more A new region based lossy compression scheme for color images is proposed. The segmentation method belongs to the split and merge category. Splitting is carried out using the watershed transform. In the merging stage, a fuzzy color preserving rule-based system and a novel one-dimensional graph structure are introduced to provide accurate results with reduced computational complexity. The compression part is

Research paper thumbnail of The relationship between visceral adiposity and left ventricular diastolic function: Results from the Baltimore Longitudinal Study of Aging

Nutrition, Metabolism and Cardiovascular Diseases, 2013

It is unclear whether subcutaneous and visceral fat are differentially correlated to the decline ... more It is unclear whether subcutaneous and visceral fat are differentially correlated to the decline in left ventricular (LV) diastolic function with aging. This study sought to examine the hypothesis that age-related changes in the regional fat distribution account for changes in LV diastolic function and to explore potential mediators of this association. In this cross-sectional study, we evaluated 843 participants of the Baltimore Longitudinal Study of Aging with echocardiogram, dual-energy X-ray absorptiometry (DEXA), abdominal computed tomography (CT) and blood tests performed at the same visit. LV diastolic function was assessed by parameters of LV relaxation (E/A ratio, Em and Em/Am ratio) and LV filling pressures (E/Em ratio). Total body fat was computed by DEXA, while visceral and subcutaneous fat were determined from abdominal CT. In multivariate models adjusted for demographics, cardiovascular risk factors, antihypertensive medications, physical activity and LV mass, both visceral and subcutaneous fat were associated with LV diastolic dysfunction. When both measures of adiposity were simultaneously included in the same model, only visceral fat was significantly associated with LV diastolic dysfunction. Triglycerides and sex-hormone binding globulin, but not adiponectin and leptin, were found to be significant mediators of the relationship between visceral fat and LV diastolic function, explaining 28-47% of the association. Bootstrapping analyses confirmed the significance of these findings. Increased visceral adiposity is associated with LV diastolic dysfunction, possibly through a metabolic pathway involving blood lipids and ectopic fat accumulation rather than adipokines.

Research paper thumbnail of Metabolic abnormalities and hypoleptinemia in α-synuclein A53T mutant mice

Neurobiology of Aging, 2014

Parkinson&amp... more Parkinson's disease (PD) patients frequently display loss of body fat mass and increased energy expenditure, and several studies have outlined a relationship between these metabolic abnormalities and disease severity, yet energy metabolism is largely unstudied in mouse models of PD. Here we characterize metabolic and physiologic responses to a high calorie diet (HCD) in mice expressing in neurons a mutant form of human α-synuclein (A53T) that causes dominantly inherited familial forms of the disease. A53T (SNCA) and wild type (WT) littermate mice were placed on a HCD for 12 weeks and evaluated for weight gain, food intake, body fat, blood plasma leptin, hunger, glucose tolerance, and energy expenditure. Results were compared with both SNCA and WT mice on a control diet. Despite consuming similar amounts of food, WT mice gained up to 66% of their original body weight on a HCD, whereas SNCA mice gained only 17%. Further, after 12 weeks on a HCD, magnetic resonance imaging analysis revealed that WT mice had significantly greater total and visceral body fat compared with SNCA mice (p < 0.007). At the age of 24 weeks SNCA mice displayed significantly increased hunger compared with WT (p < 0.03). At the age of 36 weeks, SNCA mice displayed significant hypoleptinemia compared with WT, both on a normal diet and a HCD (p < 0.03). The HCD induced insulin insensitivity in WT, but not SNCA mice, as indicated by an oral glucose tolerance test. Finally, SNCA mice displayed greater energy expenditure compared with WT, as measured in a Comprehensive Laboratory Animal Monitoring System, after 12 weeks on a HCD. Thus, SNCA mice are resistant to HCD-induced obesity and insulin resistance and display reduced body fat, increased hunger, hypoleptinemia and increased energy expenditure. Our findings reveal a profile of metabolic dysfunction in a mouse model of PD that is similar to that of human PD patients, thus providing evidence that α-synuclein pathology is sufficient to drive such metabolic abnormalities and providing an animal model for discovery of the underlying mechanisms and potential therapeutic interventions.

Research paper thumbnail of A Synergistic Model for Monitoring Brain's Changes: A Case Study

2011 IEEE 23rd International Conference on Tools with Artificial Intelligence, 2011

It is known that the early detection of chronic diseases significantly increases the life span of... more It is known that the early detection of chronic diseases significantly increases the life span of the elderly and improves the quality of life in general. Since the brain is the most valuable part of the human body, it is very important for the physicians to know the stages of aging and changes that take place during these stages and

Research paper thumbnail of A Neural Network-Based Detection of Bleeding in Sequences of WCE Images

Fifth IEEE Symposium on Bioinformatics and Bioengineering (BIBE'05), 2005

ABSTRACT This paper deals with development of a methodology for detecting bleeding in WCE images.... more ABSTRACT This paper deals with development of a methodology for detecting bleeding in WCE images. The presented methodology is based on a neural net model available in the AIIS Inc. and the results of this methods were tested at the AT research lab. The performance of our method offers promising results in comparison with the ones made by the given imaging RBIS (red blood identification system), which vary from 21% to 41%. Our method is under improvements and the expected results will reach near 80% or more.

Research paper thumbnail of Scale space segmentation of color images using watersheds and fuzzy region merging

Proceedings 2001 International Conference on Image Processing (Cat. No.01CH37205), 2001

Research paper thumbnail of Color image edge detection based on nonparametric density estimation

Proceedings 2001 International Conference on Image Processing (Cat. No.01CH37205), 2001

Abstract A novel computationally efficient adaptive algorithm to accomplish edge detection in mul... more Abstract A novel computationally efficient adaptive algorithm to accomplish edge detection in multidimensional and color images is presented. It is a statistical approach, based on local, non-parametric kernel density estimation. The location of the edge discontinuity ...

Research paper thumbnail of Metabolic abnormalities and hypoleptinemia in α-synuclein A53T mutant mice

Parkinson&amp... more Parkinson's disease (PD) patients frequently display loss of body fat mass and increased energy expenditure, and several studies have outlined a relationship between these metabolic abnormalities and disease severity, yet energy metabolism is largely unstudied in mouse models of PD. Here we characterize metabolic and physiologic responses to a high calorie diet (HCD) in mice expressing in neurons a mutant form of human α-synuclein (A53T) that causes dominantly inherited familial forms of the disease. A53T (SNCA) and wild type (WT) littermate mice were placed on a HCD for 12 weeks and evaluated for weight gain, food intake, body fat, blood plasma leptin, hunger, glucose tolerance, and energy expenditure. Results were compared with both SNCA and WT mice on a control diet. Despite consuming similar amounts of food, WT mice gained up to 66% of their original body weight on a HCD, whereas SNCA mice gained only 17%. Further, after 12 weeks on a HCD, magnetic resonance imaging analysis revealed that WT mice had significantly greater total and visceral body fat compared with SNCA mice (p < 0.007). At the age of 24 weeks SNCA mice displayed significantly increased hunger compared with WT (p < 0.03). At the age of 36 weeks, SNCA mice displayed significant hypoleptinemia compared with WT, both on a normal diet and a HCD (p < 0.03). The HCD induced insulin insensitivity in WT, but not SNCA mice, as indicated by an oral glucose tolerance test. Finally, SNCA mice displayed greater energy expenditure compared with WT, as measured in a Comprehensive Laboratory Animal Monitoring System, after 12 weeks on a HCD. Thus, SNCA mice are resistant to HCD-induced obesity and insulin resistance and display reduced body fat, increased hunger, hypoleptinemia and increased energy expenditure. Our findings reveal a profile of metabolic dysfunction in a mouse model of PD that is similar to that of human PD patients, thus providing evidence that α-synuclein pathology is sufficient to drive such metabolic abnormalities and providing an animal model for discovery of the underlying mechanisms and potential therapeutic interventions.

Research paper thumbnail of Towards segmentation of the thymus in fat and water parametric MR images

Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference, 2011

The thymus, an organ responsible for the development, selection, and maintenance of the periphera... more The thymus, an organ responsible for the development, selection, and maintenance of the peripheral T-cell population, is an important regulator of the immune system. Despite its physiological significance, it has received little attention in the medical image analysis literature. In practice, the anatomical location and variable shape of this gland pose challenges both in the image acquisition and analysis processes. We present an automated method for segmenting the thymus from water and fat parametric MR images that permits further analysis of volumetrics and tissue characterization. We compute fat ratio and water ratio parametric images and introduce the use of a stochastic edge detector that is embedded in a geometric variational segmentation model. Validation experiments of the proposed algorithm against manual delineations of the thymus indicate the applicability of our approach.

Research paper thumbnail of Localization Scale Selection for Scale-Space Segmentation

Lecture Notes in Computer Science, 2005

ABSTRACT In this work the relation between scale-space image segmentation and selection of the lo... more ABSTRACT In this work the relation between scale-space image segmentation and selection of the localization scale is examined first, and a scale selection approach is consequently proposed in the segmentation context. Considering the segmentation part, gradient watersheds are applied to the non-linear scale-space domain followed by a grouping operation. A report on localization scale selection techniques is carried out next. Furthermore a scale selection method that originates from the evolution of the probability distribution of a region uniformity measure through the generated scales is proposed. The introduced algorithm is finally compared to a previously published approach that is also introduced into the segmentation context to indicate its efficacy.

Research paper thumbnail of SEGMENTATION OF COLOR IMAGES USING A HIERARCHICAL FUZZY REGION MERGING

Research paper thumbnail of Understanding Hand Gestures Using Approximate Graph Matching....... BW Miners, OA Basir, and MS Kamel 239 On Comparing Bills of Materials: A Similarity/Distance Measure for Unordered Trees... CJ Romanowski and R. Nagi 249 Intelligent Image Prefetching for Supporting Radiologists’ Primary Reading:...

Research paper thumbnail of Recognition of Merged Characters Based on Forepart Prediction, Necessity-Sufficiency Matching, and Character-Adaptive Masking..................................................... J. Song, Z. Li, MR Lyu, and S. Cai 2 A Brain-Like Neural Network for Periodicity Analysis............. K. Voutsas, G. ...

Research paper thumbnail of Self-Configuring Scheduling Protocol for Ultrasonic Sensor Systems............ S. Srinivasan and A. Pandharipande 2517 Novel Wavelet-mFCM Algorithm for Environmental Sensor Drift Correction................................... R. Dutta 2519 Planar Optical Waveguide Platform for Gas Sensing Using Li...

Research paper thumbnail of A Generic Retrieval Method using Perceptual Color Space and Local Density Estimation

Research paper thumbnail of Special Issue on Algorithms and Tools for Bioinformatics and Bioengineering

Research paper thumbnail of NEURAL NETWORK APPROACH FOR IMAGE CHROMATIC ADAPTATION FOR SKIN COLOR DETECTION

International Journal of Neural Systems, 2007

The goal of image chromatic adaptation is to remove the effect of illumination and to obtain colo... more The goal of image chromatic adaptation is to remove the effect of illumination and to obtain color data that reflects precisely the physical contents of the scene. We present in this paper an approach to image chromatic adaptation using Neural Networks (NN) with application for detecting--adapting human skin color. The NN is trained on randomly chosen color images containing human subject under various illuminating conditions, thereby enabling the model to dynamically adapt to the changing illumination conditions. The proposed network predicts directly the illuminant estimate in the image so as to adapt to human skin color. The comparison of our method with Gray World, White Patch and NN on White Patch methods for skin color stabilization is presented. The skin regions in the NN stabilized images are successfully detected using a computationally inexpensive thresholding operation. We also present results on detecting skin regions on a data set of test images. The results are promising and suggest a new approach for adapting human skin color using neural networks.

Research paper thumbnail of Image chromatic adaptation using ANNs for skin color adaptation

16th IEEE International Conference on Tools with Artificial Intelligence, 2004

Research paper thumbnail of A survey of skin-color modeling and detection methods

Pattern Recognition, 2007

Research paper thumbnail of Watershed-based multiscale segmentation method for color images using automated scale selection

Journal of Electronic Imaging, 2005

Research paper thumbnail of Region oriented compression of color images using fuzzy inference and fast merging

Pattern Recognition, 2002

A new region based lossy compression scheme for color images is proposed. The segmentation method... more A new region based lossy compression scheme for color images is proposed. The segmentation method belongs to the split and merge category. Splitting is carried out using the watershed transform. In the merging stage, a fuzzy color preserving rule-based system and a novel one-dimensional graph structure are introduced to provide accurate results with reduced computational complexity. The compression part is

Research paper thumbnail of The relationship between visceral adiposity and left ventricular diastolic function: Results from the Baltimore Longitudinal Study of Aging

Nutrition, Metabolism and Cardiovascular Diseases, 2013

It is unclear whether subcutaneous and visceral fat are differentially correlated to the decline ... more It is unclear whether subcutaneous and visceral fat are differentially correlated to the decline in left ventricular (LV) diastolic function with aging. This study sought to examine the hypothesis that age-related changes in the regional fat distribution account for changes in LV diastolic function and to explore potential mediators of this association. In this cross-sectional study, we evaluated 843 participants of the Baltimore Longitudinal Study of Aging with echocardiogram, dual-energy X-ray absorptiometry (DEXA), abdominal computed tomography (CT) and blood tests performed at the same visit. LV diastolic function was assessed by parameters of LV relaxation (E/A ratio, Em and Em/Am ratio) and LV filling pressures (E/Em ratio). Total body fat was computed by DEXA, while visceral and subcutaneous fat were determined from abdominal CT. In multivariate models adjusted for demographics, cardiovascular risk factors, antihypertensive medications, physical activity and LV mass, both visceral and subcutaneous fat were associated with LV diastolic dysfunction. When both measures of adiposity were simultaneously included in the same model, only visceral fat was significantly associated with LV diastolic dysfunction. Triglycerides and sex-hormone binding globulin, but not adiponectin and leptin, were found to be significant mediators of the relationship between visceral fat and LV diastolic function, explaining 28-47% of the association. Bootstrapping analyses confirmed the significance of these findings. Increased visceral adiposity is associated with LV diastolic dysfunction, possibly through a metabolic pathway involving blood lipids and ectopic fat accumulation rather than adipokines.

Research paper thumbnail of Metabolic abnormalities and hypoleptinemia in α-synuclein A53T mutant mice

Neurobiology of Aging, 2014

Parkinson&amp... more Parkinson's disease (PD) patients frequently display loss of body fat mass and increased energy expenditure, and several studies have outlined a relationship between these metabolic abnormalities and disease severity, yet energy metabolism is largely unstudied in mouse models of PD. Here we characterize metabolic and physiologic responses to a high calorie diet (HCD) in mice expressing in neurons a mutant form of human α-synuclein (A53T) that causes dominantly inherited familial forms of the disease. A53T (SNCA) and wild type (WT) littermate mice were placed on a HCD for 12 weeks and evaluated for weight gain, food intake, body fat, blood plasma leptin, hunger, glucose tolerance, and energy expenditure. Results were compared with both SNCA and WT mice on a control diet. Despite consuming similar amounts of food, WT mice gained up to 66% of their original body weight on a HCD, whereas SNCA mice gained only 17%. Further, after 12 weeks on a HCD, magnetic resonance imaging analysis revealed that WT mice had significantly greater total and visceral body fat compared with SNCA mice (p < 0.007). At the age of 24 weeks SNCA mice displayed significantly increased hunger compared with WT (p < 0.03). At the age of 36 weeks, SNCA mice displayed significant hypoleptinemia compared with WT, both on a normal diet and a HCD (p < 0.03). The HCD induced insulin insensitivity in WT, but not SNCA mice, as indicated by an oral glucose tolerance test. Finally, SNCA mice displayed greater energy expenditure compared with WT, as measured in a Comprehensive Laboratory Animal Monitoring System, after 12 weeks on a HCD. Thus, SNCA mice are resistant to HCD-induced obesity and insulin resistance and display reduced body fat, increased hunger, hypoleptinemia and increased energy expenditure. Our findings reveal a profile of metabolic dysfunction in a mouse model of PD that is similar to that of human PD patients, thus providing evidence that α-synuclein pathology is sufficient to drive such metabolic abnormalities and providing an animal model for discovery of the underlying mechanisms and potential therapeutic interventions.