Pratik Singh - Independent Researcher (original) (raw)
Papers by Pratik Singh
Elemental analysis and characterization of vermilion and lipstick sample using SEM-EDS
Materials Today: Proceedings
Cell and chromatin transitions in intestinal stem cell regeneration
Genes & Development
The progeny of intestinal stem cells (ISCs) dedifferentiate in response to ISC attrition. The pre... more The progeny of intestinal stem cells (ISCs) dedifferentiate in response to ISC attrition. The precise cell sources, transitional states, and chromatin remodeling behind this activity remain unclear. In the skin, stem cell recovery after injury preserves an epigenetic memory of the damage response; whether similar memories arise and persist in regenerated ISCs is not known. We addressed these questions by examining gene activity and open chromatin at the resolution of single Neurog3-labeled mouse intestinal crypt cells, hence deconstructing forward and reverse differentiation of the intestinal secretory (Sec) lineage. We show that goblet, Paneth, and enteroendocrine cells arise by multilineage priming in common precursors, followed by selective access at thousands of cell-restricted cis-elements. Selective ablation of the ISC compartment elicits speedy reversal of chromatin and transcriptional features in large fractions of precursor and mature crypt Sec cells without obligate cell c...
2018 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), 2018
Gastroenterology, 2021
Background & Aims: Tissue metaplasia is uncommon in adults because established ciselement program... more Background & Aims: Tissue metaplasia is uncommon in adults because established ciselement programs resist rewiring. In Barrett's esophagus, the distal esophageal mucosa acquires predominantly intestinal character, with notable gastric features, and is predisposed to develop invasive cancers. We sought to understand the chromatin underpinnings of Barrett's metaplasia and why it commonly displays simultaneous gastric and intestinal properties.
Physical and Engineering Sciences in Medicine, 2020
Heartbeat classification is central to the detection of the arrhythmia. For the effective heartbe... more Heartbeat classification is central to the detection of the arrhythmia. For the effective heartbeat classification, the noise-robust features are very significant. In this work, we have proposed a noise-robust support vector machine (SVM) based heartbeat classifier. The proposed classifier utilizes a novel noise-robust morphological feature which is based on the conditional spectral moment (CSM) of the heartbeat. In addition to the proposed CSM feature, we have also employed the existing RR interval, the wavelets, and the higher-order statistics (HOS) based temporal and morphological feature sets. The noiserobustness test of the proposed CSM and all the studied feature sets is performed for the SVM based heartbeat classifier. Further, we have studied the significance of combining these temporal and morphological features on the final classification performance. For this purpose, the individual SVMs were trained for each of the feature set. The final classification is based on the ensemble of these individual SVMs. Various combining scheme such as sum, majority, and product rules are employed to ensemble the result of the individually trained SVMs. The experimental results show the noise-robustness of the proposed CSM feature. The proposed classifier gives improved overall performance compared to the existing heartbeat classification systems.
Change in Water Cycle- Important Issue on Climate Earth System
International Surgery Journal, 2021
A small evagination of parietal peritoneum forms the canal of Nuck. By the first year of life thi... more A small evagination of parietal peritoneum forms the canal of Nuck. By the first year of life this extension condenses into a fibrous cord. Cyst of canal of Nuck is a rare developmental anomaly. The inguinal canal is traversed by the spermatic cord in male and the round ligament of uterus in female. The processus vaginalis accompanies the round ligament through the inguinal canal through into the labium majus. This evagination of parietal peritoneum forms the canal of Nuck in the female. These cases are rarely seen in surgical practice. In this case series we described three clinical scenario of canal of Nuck and their management.
IEEE/ACM Transactions on Computational Biology and Bioinformatics, 2020
Cognitive radio is a promising technology for sharing the underutilized frequency bands that have... more Cognitive radio is a promising technology for sharing the underutilized frequency bands that have been licensed to primary users. However, due to the uncertainty in detecting the existence of the primary user, the secondary user may interfere with the primary users when both primary and secondary users are active simultaneously. Therefore, understanding the interference and its consequences on the cognitive network is critical. Unlike the statistical models previously reported in the literature that aim at approximation of the interference, based on the solid mathematical analysis, we propose an accurate model for describing the co-channel interference with probability density function, cumulative distribution function, mean, and variance of the interference suffered by the primary users. The proposed model not only takes into account a number of factors, such as the spectrum-sensing scheme, the spatial distribution of secondary users, and the channel conditions, including shadowing and Nakagami fading, but also gives an exact mathematical expression of the influences from these factors. The developed framework supports practical applications such as evaluating the cognitive network of any spatial shape and density of the secondary users and the methods of power control and spectrum sensing used by the secondary users. Simulation results are provided to verify the effectiveness of the analytical model.
A Novel Hardware Architecture for Non-local Means Adaptive Filter
National Academy Science Letters, 2020
A novel dedicated hardware architecture is proposed in this letter for one-dimensional non-local ... more A novel dedicated hardware architecture is proposed in this letter for one-dimensional non-local means (NLM) algorithm. The patch-based NLM algorithm has been effectively used to filter out noises from the two-dimensional images as well as various one-dimensional signals, such as an electrocardiogram (ECG) and audio signals. Dedicated hardware ensures the availability, predictability and stability of an algorithm. In this letter, an efficient hardware architecture of the NLM is proposed for removing noises from the corrupted ECG signal. The proposed architecture is implemented on a field-programmable gate array. The efficacy of the proposed architecture is verified by a firm comparison of the outputs obtained from both the hardware architecture and the software simulation performed on MATLAB. The computational complexity has also been compared for both cases (hardware and software) to show the effectiveness of the proposed hardware architecture.
Circuits, Systems, and Signal Processing, 2018
Noninvasive nature of Electrocardiogram (ECG) signal makes it widely accepted for cardiac diagnos... more Noninvasive nature of Electrocardiogram (ECG) signal makes it widely accepted for cardiac diagnosis. During the process of data acquisition, ECG signal is generally corrupted by a number of noises. Further, during ambulatory monitoring and wireless recording, ECG signal gets corrupted by additive white Gaussian noise. Without affecting the morphological structure, denoising of ECG signal is essential for proper diagnosis. This paper presents an ECG denoising method based on an effective combination of non-local means (NLM) estimation and empirical mode decomposition (EMD). Earlier works have shown that the patch-based NLM approach is insufficient for denoising the under-averaged region near high-amplitude QRS complex. To address this issue, the denoised signal obtained by NLM is decomposed into intrinsic mode functions (IMFs) using EMD in this work. Next, thresholding of the IMFs is done using the instantaneous half period criterion and the soft-thresholding to obtain the final denoised output. Furthermore, the modified empirical mode decomposition (M-EMD) is used in the place of standard EMD to reduce the computational cost. Performance of the proposed method is tested on a number of ECG signals from the MIT-BIH database. The experimental results presented in this paper show that the aforementioned shortcoming of the NLM method is addressed to a large extent. Moreover, the proposed approach provides improved performance when compared to different state-of-the-art ECG denoising methods.
Significance of modified empirical mode decomposition for ECG denoising
Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference, Jul 1, 2017
The primary objective of the presented work is to exploit the power of modified empirical mode de... more The primary objective of the presented work is to exploit the power of modified empirical mode decomposition (M-EMD) for the denoising of ECG signals. It is well known that the ECG signals get corrupted by a number of noises during the recording process. Especially, during wireless ECG recording and ambulatory patient monitoring, the signal gets corrupted by additive white Gaussian noise (AWGN). Over the years, several techniques have been proposed for ECG denoising. Among those, empirical mode decomposition (EMD) and nonlocal means (NLM) algorithm are noted to be quite effective. Further, the NLM-based approach is better in retaining the morphological characteristics in comparison to the EMD. Consequently, the two approaches are effectively combined in this paper so that each one complements the other. In the proposed approach, the noisy ECG signal is first preprocessed using the NLM algorithm. This is followed by decomposition of the partially denoised output through M-EMD. The de...
Australasian physical & engineering sciences in medicine, Jan 6, 2018
This paper presents a novel electrocardiogram (ECG) denoising approach based on variational mode ... more This paper presents a novel electrocardiogram (ECG) denoising approach based on variational mode decomposition (VMD). This work also incorporates the efficacy of the non-local means (NLM) estimation and the discrete wavelet transform (DWT) filtering technique. Current ECG denoising methods fail to remove noise from the entire frequency range of the ECG signal. To achieve the effective ECG denoising goal, the noisy ECG signal is decomposed into narrow-band variational mode functions (VMFs) using VMD method. The idea is to filter out noise from these narrow-band VMFs. To achieve that, the center frequency information associated with each VMFs is used to exclusively divide them into lower- and higher-frequency signal groups. The higher frequency VMFs were filtered out using DWT-thresholding technique. The lower frequency VMFs are denoised through NLM estimation technique. The non-recursive nature of VMD enables the parallel processing of NLM estimation and DWT filtering. The traditiona...
Biocybernetics and Biomedical Engineering, 2017
This paper presents an ECG denoising technique using merits of discrete wavelet transform (DWT) a... more This paper presents an ECG denoising technique using merits of discrete wavelet transform (DWT) and non-local means (NLM) estimation. The NLM-based approach is quite effective in removing low frequency noises but it suffers from the issue of under-averaging in the highfrequency QRS-complex region. In addition to that, the computational cost of NLM estimation is also high. The DWT, on the other hand, is effective in removing high-frequency noise but needs larger decomposition levels in order to denoise the low-frequency components. Thresholding lower-frequency components in the DWT domain often results in a loss of critical information. To overcome these drawbacks, in the proposed method, two-level DWT decomposition is first performed in order to decompose the noisy ECG signal into low-and high-frequency approximation and detail coefficients, respectively, at each level. The high frequency noise is removed by thresholding the detail coefficients at both the levels. The noise in the lower-frequency region is then removed by performing NLM estimation of Level 2 approximation coefficient. The Level 2 approximation coefficients actually represent the low-frequency envelope of the ECG. Thus, the proposed technique effectively combines the power of both NLM and DWT. At the same time, the computational cost of whole process is not more than the earlier existing techniques since NLM estimation is performed only on Level 2 approximation coefficients instead of the complete ECG signal. The proposed method is found to be superior to the existing state-of-the-art techniques when tested on the MIT-BIH arrhythmia database.
International Journal of Computer Applications, 2012
In the field of computer science, data mining is the process that attempts to discover patterns i... more In the field of computer science, data mining is the process that attempts to discover patterns in large data sets. However it deals mostly with the relationship between two or more item objects. For example A to B, where 'A' and 'B' are the item objects. But in the real life scenario not only the relationship between item objects is important, but the relationship of their frequency of occurrence is also the matter of a prime concern. The instances of two or more data items also may be correlated with each other. For example the relation between A and 2B.Where 'A' and 'B' are the data items and '2B' represents two instances of the B type of data items. This paper provides a new approach to find the occurrence dependent data patterns by conventional approaches and also compare the some inter related concepts.
International Journal of Computer Applications, 2012
An ad hoc network is a collection of wireless computers with dynamically changing topology, commu... more An ad hoc network is a collection of wireless computers with dynamically changing topology, communicating among themselves over possibly multi-hop paths, without the help of any infrastructure. Although many ad hoc network routing protocols have been proposed (AODV, SAODV, DSR etc), none of them considers or solves the security problems efficiently within the restrictions of ad hoc networks. Ad hoc networks are vulnerable to many types of attack like Denial Of Service (DOS), Byzantine Attack, Black-hole Attack, Flooding Attack, etc. In this paper we put forward an efficient and reliable security mechanism based on the AODV routing protocol which protects the ad hoc networks from different types of flooding attacks.
Journal of Global Research in Computer Science, 2012
Abstract: This electronic document gives the study of a bidirectional model, of smell as a media ... more Abstract: This electronic document gives the study of a bidirectional model, of smell as a media and it‟ s applications in the real world. This paper presents a prototype system, which uses smell as a medium to communicate information bi-directionally in the ...
Permeation through nanochannels: revealing fast kinetics
Journal of Physics: Condensed Matter, 2010
The permeation of water soluble molecules across cell membranes is controlled by channel-forming ... more The permeation of water soluble molecules across cell membranes is controlled by channel-forming proteins and, in particular, the channel surface determines the selectivity. An adequate method to study the properties of these channels is electrophysiology and, in particular, analyzing the ion current fluctuation in the presence of permeating solutes. Ion current fluctuation analysis provides information on possible interactions of solutes with the channel surface. Due to the limited time resolution, fast permeation events are not visible using standard techniques. Here, we demonstrate that miniaturization of the lipid bilayer; varying the temperature or changing the solvent may enhance the resolution. Although electrophysiology is considered as a single molecule technique, it does not provide atomic resolution. Molecular details of solute permeation can be revealed by combining electrophysiology and all-atom computer modeling; these methods include ion conductance, selectivity, ion pair formation, and rate limiting interactions of the solute with the channel walls during permeation.
Avian Pathology, 1998
Mycoplasma gallisepticum (MG) is one of the aetiologic agents of chronic respiratory disease in c... more Mycoplasma gallisepticum (MG) is one of the aetiologic agents of chronic respiratory disease in chickens and infectious sinusitis in turkeys. We investigated humoral and cellular immune mechanisms following experimental infection with four different strains of MG. Peripheral blood leukocytes (PBL) obtained from chickens were examined for proliferation using antigen preparations of whole cell MG as stimuli in vitro. A consistent lymphoproliferative response was observed against the homologous whole cell antigens in the group of chickens infected with strain PG31. Significant lymphoproliferation was detected as early as 1 week post-infection. We further characterized antigen-specific proliferation by measuring the production of interferon and nitric oxide by the PBL of infected chickens. Consistent with lymphoproliferation, we also detected the presence of interferon and nitric oxide in vitro in antigen-stimulated cultures. These results indicate a possible role of cell-mediated immune responses in the development of immunity following MG infection in chickens.
Journal of nanobiotechnology, Jan 13, 2006
Specific targeting of tumor cells is an important goal for the design of nanotherapeutics for the... more Specific targeting of tumor cells is an important goal for the design of nanotherapeutics for the treatment of cancer. Recently, viruses have been explored as nano-containers for specific targeting applications, however these systems typically require modification of the virus surface using chemical or genetic means to achieve tumor-specific delivery. Interestingly, there exists a subset of viruses with natural affinity for receptors on tumor cells that could be exploited for nanotechnology applications. For example, the canine parvovirus (CPV) utilizes transferrin receptors (TfRs) for binding and cell entry into canine as well as human cells. TfRs are over-expressed by a variety of tumor cells and are widely being investigated for tumor-targeted drug delivery. We explored whether the natural tropism of CPV to TfRs could be harnessed for targeting tumor cells. Towards this goal, CPV virus-like particles (VLPs) produced by expression of the CPV-VP2 capsid protein in a baculovirus exp...
Virology, 2005
The plant virus, cowpea mosaic virus (CPMV), is increasingly being used as a nanoparticle platfor... more The plant virus, cowpea mosaic virus (CPMV), is increasingly being used as a nanoparticle platform for multivalent display of peptides. A growing variety of applications have employed the CPMV display technology including vaccines, antiviral therapeutics, nanoblock chemistry, and materials science. CPMV chimeras can be inexpensively produced from experimentally infected cowpea plants and are completely stable at 37-C and low pH, suggesting that they could be used as edible or mucosally-delivered vaccines or therapeutics. However, the fate of CPMV particles in vivo, or following delivery via the oral route, is unknown. To address this question, we examined CPMV in vitro and in vivo. CPMV was shown to be stable under simulated gastric conditions in vitro. The pattern of localization of CPMV particles to mouse tissues following oral or intravenous dosing was then determined. For several days following oral or intravenous inoculation, CPMV was found in a wide variety of tissues throughout the body, including the spleen, kidney, liver, lung, stomach, small intestine, lymph nodes, brain, and bone marrow. CPMV particles were detected after cardiac perfusion, suggesting that the particles entered the tissues. This pattern was confirmed using methods to specifically detect the viral capsid proteins and the internal viral RNA. The stability of CPMV virions in the gastrointestinal tract followed by their systemic dissemination supports their use as orally bioavailable nanoparticles.
Elemental analysis and characterization of vermilion and lipstick sample using SEM-EDS
Materials Today: Proceedings
Cell and chromatin transitions in intestinal stem cell regeneration
Genes & Development
The progeny of intestinal stem cells (ISCs) dedifferentiate in response to ISC attrition. The pre... more The progeny of intestinal stem cells (ISCs) dedifferentiate in response to ISC attrition. The precise cell sources, transitional states, and chromatin remodeling behind this activity remain unclear. In the skin, stem cell recovery after injury preserves an epigenetic memory of the damage response; whether similar memories arise and persist in regenerated ISCs is not known. We addressed these questions by examining gene activity and open chromatin at the resolution of single Neurog3-labeled mouse intestinal crypt cells, hence deconstructing forward and reverse differentiation of the intestinal secretory (Sec) lineage. We show that goblet, Paneth, and enteroendocrine cells arise by multilineage priming in common precursors, followed by selective access at thousands of cell-restricted cis-elements. Selective ablation of the ISC compartment elicits speedy reversal of chromatin and transcriptional features in large fractions of precursor and mature crypt Sec cells without obligate cell c...
2018 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), 2018
Gastroenterology, 2021
Background & Aims: Tissue metaplasia is uncommon in adults because established ciselement program... more Background & Aims: Tissue metaplasia is uncommon in adults because established ciselement programs resist rewiring. In Barrett's esophagus, the distal esophageal mucosa acquires predominantly intestinal character, with notable gastric features, and is predisposed to develop invasive cancers. We sought to understand the chromatin underpinnings of Barrett's metaplasia and why it commonly displays simultaneous gastric and intestinal properties.
Physical and Engineering Sciences in Medicine, 2020
Heartbeat classification is central to the detection of the arrhythmia. For the effective heartbe... more Heartbeat classification is central to the detection of the arrhythmia. For the effective heartbeat classification, the noise-robust features are very significant. In this work, we have proposed a noise-robust support vector machine (SVM) based heartbeat classifier. The proposed classifier utilizes a novel noise-robust morphological feature which is based on the conditional spectral moment (CSM) of the heartbeat. In addition to the proposed CSM feature, we have also employed the existing RR interval, the wavelets, and the higher-order statistics (HOS) based temporal and morphological feature sets. The noiserobustness test of the proposed CSM and all the studied feature sets is performed for the SVM based heartbeat classifier. Further, we have studied the significance of combining these temporal and morphological features on the final classification performance. For this purpose, the individual SVMs were trained for each of the feature set. The final classification is based on the ensemble of these individual SVMs. Various combining scheme such as sum, majority, and product rules are employed to ensemble the result of the individually trained SVMs. The experimental results show the noise-robustness of the proposed CSM feature. The proposed classifier gives improved overall performance compared to the existing heartbeat classification systems.
Change in Water Cycle- Important Issue on Climate Earth System
International Surgery Journal, 2021
A small evagination of parietal peritoneum forms the canal of Nuck. By the first year of life thi... more A small evagination of parietal peritoneum forms the canal of Nuck. By the first year of life this extension condenses into a fibrous cord. Cyst of canal of Nuck is a rare developmental anomaly. The inguinal canal is traversed by the spermatic cord in male and the round ligament of uterus in female. The processus vaginalis accompanies the round ligament through the inguinal canal through into the labium majus. This evagination of parietal peritoneum forms the canal of Nuck in the female. These cases are rarely seen in surgical practice. In this case series we described three clinical scenario of canal of Nuck and their management.
IEEE/ACM Transactions on Computational Biology and Bioinformatics, 2020
Cognitive radio is a promising technology for sharing the underutilized frequency bands that have... more Cognitive radio is a promising technology for sharing the underutilized frequency bands that have been licensed to primary users. However, due to the uncertainty in detecting the existence of the primary user, the secondary user may interfere with the primary users when both primary and secondary users are active simultaneously. Therefore, understanding the interference and its consequences on the cognitive network is critical. Unlike the statistical models previously reported in the literature that aim at approximation of the interference, based on the solid mathematical analysis, we propose an accurate model for describing the co-channel interference with probability density function, cumulative distribution function, mean, and variance of the interference suffered by the primary users. The proposed model not only takes into account a number of factors, such as the spectrum-sensing scheme, the spatial distribution of secondary users, and the channel conditions, including shadowing and Nakagami fading, but also gives an exact mathematical expression of the influences from these factors. The developed framework supports practical applications such as evaluating the cognitive network of any spatial shape and density of the secondary users and the methods of power control and spectrum sensing used by the secondary users. Simulation results are provided to verify the effectiveness of the analytical model.
A Novel Hardware Architecture for Non-local Means Adaptive Filter
National Academy Science Letters, 2020
A novel dedicated hardware architecture is proposed in this letter for one-dimensional non-local ... more A novel dedicated hardware architecture is proposed in this letter for one-dimensional non-local means (NLM) algorithm. The patch-based NLM algorithm has been effectively used to filter out noises from the two-dimensional images as well as various one-dimensional signals, such as an electrocardiogram (ECG) and audio signals. Dedicated hardware ensures the availability, predictability and stability of an algorithm. In this letter, an efficient hardware architecture of the NLM is proposed for removing noises from the corrupted ECG signal. The proposed architecture is implemented on a field-programmable gate array. The efficacy of the proposed architecture is verified by a firm comparison of the outputs obtained from both the hardware architecture and the software simulation performed on MATLAB. The computational complexity has also been compared for both cases (hardware and software) to show the effectiveness of the proposed hardware architecture.
Circuits, Systems, and Signal Processing, 2018
Noninvasive nature of Electrocardiogram (ECG) signal makes it widely accepted for cardiac diagnos... more Noninvasive nature of Electrocardiogram (ECG) signal makes it widely accepted for cardiac diagnosis. During the process of data acquisition, ECG signal is generally corrupted by a number of noises. Further, during ambulatory monitoring and wireless recording, ECG signal gets corrupted by additive white Gaussian noise. Without affecting the morphological structure, denoising of ECG signal is essential for proper diagnosis. This paper presents an ECG denoising method based on an effective combination of non-local means (NLM) estimation and empirical mode decomposition (EMD). Earlier works have shown that the patch-based NLM approach is insufficient for denoising the under-averaged region near high-amplitude QRS complex. To address this issue, the denoised signal obtained by NLM is decomposed into intrinsic mode functions (IMFs) using EMD in this work. Next, thresholding of the IMFs is done using the instantaneous half period criterion and the soft-thresholding to obtain the final denoised output. Furthermore, the modified empirical mode decomposition (M-EMD) is used in the place of standard EMD to reduce the computational cost. Performance of the proposed method is tested on a number of ECG signals from the MIT-BIH database. The experimental results presented in this paper show that the aforementioned shortcoming of the NLM method is addressed to a large extent. Moreover, the proposed approach provides improved performance when compared to different state-of-the-art ECG denoising methods.
Significance of modified empirical mode decomposition for ECG denoising
Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference, Jul 1, 2017
The primary objective of the presented work is to exploit the power of modified empirical mode de... more The primary objective of the presented work is to exploit the power of modified empirical mode decomposition (M-EMD) for the denoising of ECG signals. It is well known that the ECG signals get corrupted by a number of noises during the recording process. Especially, during wireless ECG recording and ambulatory patient monitoring, the signal gets corrupted by additive white Gaussian noise (AWGN). Over the years, several techniques have been proposed for ECG denoising. Among those, empirical mode decomposition (EMD) and nonlocal means (NLM) algorithm are noted to be quite effective. Further, the NLM-based approach is better in retaining the morphological characteristics in comparison to the EMD. Consequently, the two approaches are effectively combined in this paper so that each one complements the other. In the proposed approach, the noisy ECG signal is first preprocessed using the NLM algorithm. This is followed by decomposition of the partially denoised output through M-EMD. The de...
Australasian physical & engineering sciences in medicine, Jan 6, 2018
This paper presents a novel electrocardiogram (ECG) denoising approach based on variational mode ... more This paper presents a novel electrocardiogram (ECG) denoising approach based on variational mode decomposition (VMD). This work also incorporates the efficacy of the non-local means (NLM) estimation and the discrete wavelet transform (DWT) filtering technique. Current ECG denoising methods fail to remove noise from the entire frequency range of the ECG signal. To achieve the effective ECG denoising goal, the noisy ECG signal is decomposed into narrow-band variational mode functions (VMFs) using VMD method. The idea is to filter out noise from these narrow-band VMFs. To achieve that, the center frequency information associated with each VMFs is used to exclusively divide them into lower- and higher-frequency signal groups. The higher frequency VMFs were filtered out using DWT-thresholding technique. The lower frequency VMFs are denoised through NLM estimation technique. The non-recursive nature of VMD enables the parallel processing of NLM estimation and DWT filtering. The traditiona...
Biocybernetics and Biomedical Engineering, 2017
This paper presents an ECG denoising technique using merits of discrete wavelet transform (DWT) a... more This paper presents an ECG denoising technique using merits of discrete wavelet transform (DWT) and non-local means (NLM) estimation. The NLM-based approach is quite effective in removing low frequency noises but it suffers from the issue of under-averaging in the highfrequency QRS-complex region. In addition to that, the computational cost of NLM estimation is also high. The DWT, on the other hand, is effective in removing high-frequency noise but needs larger decomposition levels in order to denoise the low-frequency components. Thresholding lower-frequency components in the DWT domain often results in a loss of critical information. To overcome these drawbacks, in the proposed method, two-level DWT decomposition is first performed in order to decompose the noisy ECG signal into low-and high-frequency approximation and detail coefficients, respectively, at each level. The high frequency noise is removed by thresholding the detail coefficients at both the levels. The noise in the lower-frequency region is then removed by performing NLM estimation of Level 2 approximation coefficient. The Level 2 approximation coefficients actually represent the low-frequency envelope of the ECG. Thus, the proposed technique effectively combines the power of both NLM and DWT. At the same time, the computational cost of whole process is not more than the earlier existing techniques since NLM estimation is performed only on Level 2 approximation coefficients instead of the complete ECG signal. The proposed method is found to be superior to the existing state-of-the-art techniques when tested on the MIT-BIH arrhythmia database.
International Journal of Computer Applications, 2012
In the field of computer science, data mining is the process that attempts to discover patterns i... more In the field of computer science, data mining is the process that attempts to discover patterns in large data sets. However it deals mostly with the relationship between two or more item objects. For example A to B, where 'A' and 'B' are the item objects. But in the real life scenario not only the relationship between item objects is important, but the relationship of their frequency of occurrence is also the matter of a prime concern. The instances of two or more data items also may be correlated with each other. For example the relation between A and 2B.Where 'A' and 'B' are the data items and '2B' represents two instances of the B type of data items. This paper provides a new approach to find the occurrence dependent data patterns by conventional approaches and also compare the some inter related concepts.
International Journal of Computer Applications, 2012
An ad hoc network is a collection of wireless computers with dynamically changing topology, commu... more An ad hoc network is a collection of wireless computers with dynamically changing topology, communicating among themselves over possibly multi-hop paths, without the help of any infrastructure. Although many ad hoc network routing protocols have been proposed (AODV, SAODV, DSR etc), none of them considers or solves the security problems efficiently within the restrictions of ad hoc networks. Ad hoc networks are vulnerable to many types of attack like Denial Of Service (DOS), Byzantine Attack, Black-hole Attack, Flooding Attack, etc. In this paper we put forward an efficient and reliable security mechanism based on the AODV routing protocol which protects the ad hoc networks from different types of flooding attacks.
Journal of Global Research in Computer Science, 2012
Abstract: This electronic document gives the study of a bidirectional model, of smell as a media ... more Abstract: This electronic document gives the study of a bidirectional model, of smell as a media and it‟ s applications in the real world. This paper presents a prototype system, which uses smell as a medium to communicate information bi-directionally in the ...
Permeation through nanochannels: revealing fast kinetics
Journal of Physics: Condensed Matter, 2010
The permeation of water soluble molecules across cell membranes is controlled by channel-forming ... more The permeation of water soluble molecules across cell membranes is controlled by channel-forming proteins and, in particular, the channel surface determines the selectivity. An adequate method to study the properties of these channels is electrophysiology and, in particular, analyzing the ion current fluctuation in the presence of permeating solutes. Ion current fluctuation analysis provides information on possible interactions of solutes with the channel surface. Due to the limited time resolution, fast permeation events are not visible using standard techniques. Here, we demonstrate that miniaturization of the lipid bilayer; varying the temperature or changing the solvent may enhance the resolution. Although electrophysiology is considered as a single molecule technique, it does not provide atomic resolution. Molecular details of solute permeation can be revealed by combining electrophysiology and all-atom computer modeling; these methods include ion conductance, selectivity, ion pair formation, and rate limiting interactions of the solute with the channel walls during permeation.
Avian Pathology, 1998
Mycoplasma gallisepticum (MG) is one of the aetiologic agents of chronic respiratory disease in c... more Mycoplasma gallisepticum (MG) is one of the aetiologic agents of chronic respiratory disease in chickens and infectious sinusitis in turkeys. We investigated humoral and cellular immune mechanisms following experimental infection with four different strains of MG. Peripheral blood leukocytes (PBL) obtained from chickens were examined for proliferation using antigen preparations of whole cell MG as stimuli in vitro. A consistent lymphoproliferative response was observed against the homologous whole cell antigens in the group of chickens infected with strain PG31. Significant lymphoproliferation was detected as early as 1 week post-infection. We further characterized antigen-specific proliferation by measuring the production of interferon and nitric oxide by the PBL of infected chickens. Consistent with lymphoproliferation, we also detected the presence of interferon and nitric oxide in vitro in antigen-stimulated cultures. These results indicate a possible role of cell-mediated immune responses in the development of immunity following MG infection in chickens.
Journal of nanobiotechnology, Jan 13, 2006
Specific targeting of tumor cells is an important goal for the design of nanotherapeutics for the... more Specific targeting of tumor cells is an important goal for the design of nanotherapeutics for the treatment of cancer. Recently, viruses have been explored as nano-containers for specific targeting applications, however these systems typically require modification of the virus surface using chemical or genetic means to achieve tumor-specific delivery. Interestingly, there exists a subset of viruses with natural affinity for receptors on tumor cells that could be exploited for nanotechnology applications. For example, the canine parvovirus (CPV) utilizes transferrin receptors (TfRs) for binding and cell entry into canine as well as human cells. TfRs are over-expressed by a variety of tumor cells and are widely being investigated for tumor-targeted drug delivery. We explored whether the natural tropism of CPV to TfRs could be harnessed for targeting tumor cells. Towards this goal, CPV virus-like particles (VLPs) produced by expression of the CPV-VP2 capsid protein in a baculovirus exp...
Virology, 2005
The plant virus, cowpea mosaic virus (CPMV), is increasingly being used as a nanoparticle platfor... more The plant virus, cowpea mosaic virus (CPMV), is increasingly being used as a nanoparticle platform for multivalent display of peptides. A growing variety of applications have employed the CPMV display technology including vaccines, antiviral therapeutics, nanoblock chemistry, and materials science. CPMV chimeras can be inexpensively produced from experimentally infected cowpea plants and are completely stable at 37-C and low pH, suggesting that they could be used as edible or mucosally-delivered vaccines or therapeutics. However, the fate of CPMV particles in vivo, or following delivery via the oral route, is unknown. To address this question, we examined CPMV in vitro and in vivo. CPMV was shown to be stable under simulated gastric conditions in vitro. The pattern of localization of CPMV particles to mouse tissues following oral or intravenous dosing was then determined. For several days following oral or intravenous inoculation, CPMV was found in a wide variety of tissues throughout the body, including the spleen, kidney, liver, lung, stomach, small intestine, lymph nodes, brain, and bone marrow. CPMV particles were detected after cardiac perfusion, suggesting that the particles entered the tissues. This pattern was confirmed using methods to specifically detect the viral capsid proteins and the internal viral RNA. The stability of CPMV virions in the gastrointestinal tract followed by their systemic dissemination supports their use as orally bioavailable nanoparticles.