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Search Results: 1 - 10 of 401292 matches for " M Kesavan "
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Watermarking of Digital Video Stream for Source Authentication
Kesavan Gopal,M. Madhavi Latha
International Journal of Computer Science Issues , 2010,
Abstract: In this paper, a novel idea of embedding a watermark pattern in BT.656 raw digital video stream is proposed and implemented in Field Programmable Gate Array (FPGA) hardware for real time authentication. Earlier many watermarking algorithms are proposed for video authentication both in compressed as well as in uncompressed domain. A watermark is introduced in the stream either at source, channel or at the receiver. Most of methods targets embedding the watermark in the compressed domain before being transmitted over the channel or at the play back, very few techniques concentrates on the raw video data at the source. In this proposed work, we embed the watermark pattern at the very beginning stage of digital video production i.e., at BT.656 video interface. A 64-bit length device DNA or user defined payload is embedded as an invisible watermark. Optionally visible logo is used as a visible watermark. Embedding of watermark bits is done in Discrete Wavelet Transform (DWT) domain for its robustness against various attacks. Only the luminance component of the BT.656 video stream is watermarked. An experimental result shows that the proposed method is operating in real time while maintaining the good perceptual visual quality measured in terms of PSNR.
Optimal Design of Fuzzy Based Power System Stabilizer Self Tuned by Robust Search Algorithm
M. Mary Linda,N. Kesavan Nair
Computer Science , 2009,
Abstract: In the interconnected power system network, instability problems are caused mainly by the low frequency oscillations of 0.2 to 2.5 Hz. The supplementary control signal in addition with AVR and high gain excitation systems are provided by means of Power System Stabilizer (PSS). Conventional power system stabilizers provide effective damping only on a particular operating point. But fuzzy based PSS provides good damping for a wide range of operating points. The bottlenecks faced in designing a fuzzy logic controller can be minimized by using appropriate optimization techniques like Genetic Algorithm, Particle Swam Optimization, Ant Colony Optimization etc.In this paper the membership functions of FLC are optimized by the new breed optimization technique called Genetic Algorithm. This design methodology is implemented on a Single Machine Infinite Bus (SMIB) system. Simulation results on SMIB show the effectiveness and robustness of the proposed PSS over a wide range of operating conditions and system configurations.
Distorted Waveform Balancing Using an Artificial Bee Colony (ABC) Based Optimal Control for Mitigating Total Harmonics in Single Phase Inverter  [PDF]
N. M. Spencer Prathap Singh, Kesavan Nair, T. Ajith Bosco Raj
Circuits and Systems (CS) , 2016, DOI: 10.4236/cs.2016.79187
Abstract: The main objective of this paper is to reduce the total harmonics in a single phase voltage source inverter using Artificial Bee Colony (ABC) optimization technique for critical load applications. Single phase inverter is a non-linear load using power electronic components causing distortions in the load voltage and current wave patterns from the sinusoidal waveforms due to harmonics. The mapping state space model for a full bridge voltage source inverter was developed using output load resistance. An optimal ABC technique has been designed and optimized values are estimated using a full bridge voltage controlled inverter using Proportional Integral Algorithm. The MATLAB/SIMULINK tool and Experimental setup were implemented and their THD values were estimated. Also this ABC scheme is compared with the previous results such as PI Algorithm, Fuzzy logic controller and Neuro-fuzzy controllers. From the simulation and experimental results using ABC algorithm, it is observed that the total harmonics are mitigated considerably compared to previous results with respect to the power quality standards such as IEEE-519 and IEC 61000.
Neutrophils in Tuberculosis: will the code be unlocked?
K Karthik,M Kesavan,P Tamilmahan,M Saravanan
Veterinary World , 2013, DOI: 10.5455/vetworld.2013.118-121
Abstract: Tuberculosis is a devastating disease throughout the world both in humans and animals. Its history is vast, which dates back to era of Robert Koch. There is a huge amount of immunological studies in the aspect of tuberculosis but there remain many unanswered questions. Neutrophils, cells of First line defence are being neglected in tuberculosis. Macrophages are considered as the key player in case of tuberculosis. Researches reveal that neutrophils play some interesting roles; it can be called as a bi-directional weapon. It plays instrumental role in killing mycobacterium, recruiting macrophages and also works hand in hand with macrophages in order halt the spread of the organism. Neutrophils also activates innate immunity, secretes some substances like ectosomes, which favour in trapping the mycobacterial organisms. Whether neutrophils drills the mycobacterium or gets succumbed to it depends on the stage of infection. Neutrophils at times act like a suicidal bomber, by carrying the organisms to different organs and spreading the infections. In chronic cases they are also implicated to granuloma formation, the classic sign of TB. [Vet World 2013; 6(2.000): 118-121]
Investigation on Microorganisms and their Degradation Efficiency in Paper and Pulp Mill Effluent  [PDF]
Radhakrishnan Saraswathi, Manghatai Kesavan Saseetharan
Journal of Water Resource and Protection (JWARP) , 2010, DOI: 10.4236/jwarp.2010.27076
Abstract: Paper and pulp mill is a source of major pollution generating industry leaving huge amount of intensely colored effluent to the receiving end. Rapid increase of population and the increased demand for industrial establishments to meet human needs have created problems such as over exploitation of available resources, increased pollution taking place on land, air and water environment. The intention of this research paper is to identify predominant bacteria and fungi in paper and pulp mill effluent in addition to evaluate the degradation efficiency of individual isolates and combination of isolates. Treatment efficiency of individual isolates and combination of isolates are evaluated by shake flask method. Combination of Pseudomonas Alkaligenes, Bacillus subtilis along with Trichoderma reesei shows higher BOD, COD reduction of 99% and 85% respectively. As individual isolates Pseudomonas Alkaligenes show 92% BOD reduction and 77% COD reduction over other bacterial isolates and Trichoderma reesei removed 99% BOD and 80% COD respectively.
Dark Energy
Aruna Kesavan
Physics , 2009,
Abstract: Dark energy is one of the mysteries of modern science. It is unlike any known form of matter or energy and has been detected so far only by its gravitational effect of repulsion. Owing to its effects being discernible only at very very large distance scales, dark energy was only detected at the turn of the last century when technology had advanced enough to observe a greater part of the universe in finer detail. The aim of the report is to gain a better understanding of the mysterious dark energy. To this end, both theoretical methods and observational evidence are studied. Three lines of evidence, namely, the redshift data of type Ia supernovae, estimates of the age of the universe by various methods, and the anisotropies in the cosmic background radiation, build the case for existence of dark energy. The supernova data indicate that the expansion of the universe is accelerating. The ages of the oldest star clusters in the universe indicate that the universe is older than previously thought to be. The anisotropies in the cosmic microwave background radiation suggest that the universe is globally spatially flat. If one agrees that the dynamics of the geometry of the universe is dictated by its energy-momentum content through Einstein's general theory of relativity, then all these independent observations lead to the amazing conclusion that the amount of energy in the universe that is presently accounted for by matter and radiation is not enough to explain these phenomena. One of the best and simplest explanations for dark energy is the cosmological constant. While it does not answer all questions, it certainly does manage to explain the observations. The following report examines in some detail the dark energy problem and the candidacy of the cosmological constant as the right theory of dark energy.
Identification and validation of genes involved in gastric tumorigenesis
Thangarajan Rajkumar, Neelakantan Vijayalakshmi, Gopisetty Gopal, Kesavan Sabitha, Sundersingh Shirley, Uthandaraman M Raja, Seshadri A Ramakrishnan
Cancer Cell International , 2010, DOI: 10.1186/1475-2867-10-45
Abstract: We used 24 gastric cancers, 20 Paired normal (PN) and 5 apparently normal gastric tissues obtained from patients with non-gastric cancers (Apparently normal - AN) for the microarray study followed by validation of the significant genes (n = 63) by relative quantitation using Taqman Low Density Array Real Time PCR. We then used a custom made Quantibody protein array to validate the expression of 15 proteins in gastric tissues (4 AN, 9 PN and 9 gastric cancers). The same array format was used to study the plasma levels of these proteins in 58 patients with gastric cancers and 18 from patients with normal/non-malignant gastric conditions.Seventeen genes (ASPN, CCL15/MIP-1δ, MMP3, SPON2, PRSS2, CCL3, TMEPAI/PMEPAI, SIX3, MFNG, SOSTDC1, SGNE1, SST, IGHA1, AKR1B10, FCGBP, ATP4B, NCAPH2) were shown to be differentially expressed between the tumours and the paired normal, for the first time. EpCAM (p = 0.0001), IL8 (p = 0.0003), CCL4/MIP-1β (p = 0.0026), CCL20/MIP-3α (p = 0.039) and TIMP1 (p = 0.0017) tissue protein levels were significantly different (Mann Whitney U test) between tumours versus AN & PN. In addition, median plasma levels of IL8, CXCL9/MIG, CCL3/MIP-1α, CCL20/MIP-3α, PDGFR-B and TIMP1 proteins were significantly different between the non-malignant group and the gastric cancer group. The post-surgical levels of EpCAM, IGFBP3, IL8, CXCL10/IP10, CXCL9/MIG, CCL3/MIP-1α, CCL20/MIP-3α, SPP1/OPN and PDGFR-B showed a uniform drop in all the samples studied.Our study has identified several genes differentially expressed in gastric cancers, some for the first time. Some of these have been confirmed at the protein level, as well. Some of these proteins will need to be evaluated further for their potential as diagnostic biomarkers in gastric cancers and some could be useful as follow-up markers in gastric cancer.Gastric cancer is one of the common cancers seen in South India, ranked 2nd among men and 5th among women in the Chennai Metropolitan area [1]. Of the patients
Transgenic Overexpression of Ephrin B1 in Bone Cells Promotes Bone Formation and an Anabolic Response to Mechanical Loading in Mice
Shaohong Cheng, Chandrasekhar Kesavan, Subburaman Mohan, Xuezhong Qin, Catrina M. Alarcon, Jon Wergedal, Weirong Xing
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0069051
Abstract: To test if ephrin B1 overexpression enhances bone mass, we generated transgenic mice overexpressing ephrin B1 under the control of a 3.6 kb rat collagen 1A1 promoter (Col3.6-Tgefnb1). Col3.6-Tgefnb1 mice express 6-, 12- and 14-fold greater levels of full-length ephrin B1 protein in bone marrow stromal cells, calvarial osteoblasts, and osteoclasts, respectively. The long bones of both genders of Col3.6-Tgefnb1 mice have increased trabecular bone volume, trabecular number, and trabecular thickness and decreased trabecular separation. Enhanced bone formation and decreased bone resorption contributed to this increase in trabecular bone mass in Col3.6-Tgefnb1 mice. Consistent with these findings, our in vitro studies showed that overexpression of ephrin B1 increased osteoblast differentiation and mineralization, osterix and collagen 1A1 expression in bone marrow stromal cells. Interaction of ephrin B1 with soluble clustered EphB2-Fc decreased osteoclast precursor differentiation into multinucleated cells. Furthermore, we demonstrated that the mechanical loading-induced increase in EphB2 expression and newly formed bone were significantly greater in the Col3.6-Tgefnb1 mice than in WT littermate controls. Our findings that overexpression of ephrin B1 in bone cells enhances bone mass and promotes a skeletal anabolic response to mechanical loading suggest that manipulation of ephrin B1 actions in bone may provide a means to sensitize the skeleton to mechanical strain to stimulate new bone formation.
Lack of anabolic response to skeletal loading in mice with targeted disruption of the pleiotrophin gene
Chandrasekhar Kesavan, Subburaman Mohan
BMC Research Notes , 2008, DOI: 10.1186/1756-0500-1-124
Abstract: Four-point bending caused an acute increase in PTN expression (2-fold) within 2 days of loading and further increased (3–6 fold) with continued loading. This increase was also seen in 16 and 36-week old mice. Based on these findings, we next used PTN knockout (KO) mice to evaluate the cause and effect relationship. Quantitative analysis showed that two weeks of ML induced changes in vBMD and bone size in the PTN KO mice (8% and 6% vs. non-loaded bones) were not significantly different from control mice (11% and 8% in vBMD and bone size vs. non-loaded bones).Our results imply that PTN is not a key upstream mediator of the anabolic effects of ML on the skeleton.Mechanical loading is now recognized as an important stimulator of bone formation. Numerous studies in animal and humans, using various loading models have demonstrated that loading increases bone mass while unloading decreases bone mass [1-6]. To date, reports have shown that several growth factors and signaling pathways are known to be activated by ML [7-11]. However, the relative contribution of each of these pathways to ML induced bone formation is not known. We previously, using genome-wide microarray approach have reported that mechanical loading by four-point bending caused a 4-fold increase in Heparin binding growth factor, otherwise known as PTN, in a good responder B6 mouse [7]. PTN, a 36 amino acid bone growth factor rich in lysine and cysteine residues, is also known as Osteoblast Specific Factor 1. PTN is involved in diverse functions, which includes: cell recruitment, cell attachment and proliferation, differentiation, angiogensis, and neurogenesis [12-14]. In vitro studies have demonstrated that PTN has the ability to promote adhesion, migration, expansion and differentiation of human osteoprogenitor and MC3T3-E1 cells [15-17]. In vivo studies using transgenic approach have shown that ovariectomy induced bone loss, due to estrogen deficiency, were protected by an increase in the expression of the
FINDING NEW INHIBITORS FOR EML4-ALK FUSION PROTEIN: A COMPUTATIONAL APPROACH
Kesavan Sabitha,Ramshankar Vijayalakshmi
International Research Journal of Pharmacy , 2012,
Abstract: The fusion between echinoderm microtubule-associated protein-like 4 (EML4) and anaplastic lymphoma kinase (ALK) has recently been identified in a subset of non-small cell lung cancers (NSCLC). PF-02341066 (crizotinib) is an orally bioavailable ALK inhibitor currently under clinical development. PF-02341066 in EML4-ALK NSCLC was designed for patients not eligible for the phase III trial or patients randomized to chemotherapy who subsequently developed progressive disease. PF-02341066 is a dual inhibitor of mesenchymal epithelial transition growth factor (c-met) and anaplastic lymphoma kinase translocation gene and caused tumour shrinkage in 52% of patients in a phase I study. However, some studies also show denovo mutations within the kinase domain of EML4-ALK that confers resistance to multiple ALK inhibitors. Hence development of new inhibitors with better binding affinities towards the EML4-ALK is the need of the hour for subsequent clinical validation. Computational (virtual) screening of drug-like compounds against the protein targets like EML4-ALK, might help to identify specific lead inhibitors more efficiently. The Protein- Ligand interaction plays a significant role in structure based drug designing. In the current study, we have considered EML4-ALK, a fusion protein involved in NSCLCs as a receptor and NCI subset Ligands as drugs. The receptor was docked to the NCI database of drugs and a docking score was calculated using GLIDE docking software. Based on the docking score, we choose the best drugs and analyzed its ADME properties using Qikprop tool. The results of this analysis show some novel compounds that can be further evaluated as EML4-ALK inhibitors in experimental NSCLC cell lines. The study further supports the application of computer-aided techniques to the discovery of novel and specific drug for EML4-ALK fusion protein.
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