OALib Journal期刊

ISSN: 2333-9721



匹配条件: “Shree Divyya” ,找到相关结果约94条。
Clinical utility of polymorphisms in one-carbon metabolism for breast cancer risk prediction
Shaik Mohammad Naushad,Shree Divyya,Addepalli Pavani,Yedluri Rupasree
Journal of Medical and Allied Sciences , 2011,
Abstract: This study addresses the issues in translating the laboratory derived data obtained during discovery phase of research to a clinical setting using a breast cancer model. Laboratory-based risk assessment indi-cated that a family history of breast cancer, reduced folate carrier 1 (RFC1) G80A, thymidylate synthase (TYMS) 5’-UTR 28bp tandem repeat, methylene tetrahydrofolate reductase (MTHFR) C677T and catecholamine-O-methyl transferase (COMT) genetic polymorphisms in one-carbon metabolic pathway increase the risk for breast cancer. Glutamate carboxypeptidase II (GCPII) C1561T and cytosolic serine hydroxymethyl transferase (cSHMT) C1420T polymorphisms were found to decrease breast cancer risk. In order to test the clinical validity of this information in the risk prediction of breast cancer, data was stratified based on number of protective alleles into four categories and in each category sensitivity and 1-specificity values were obtained based on the distribution of number of risk alleles in cases and controls. Receiver operating characteristic (ROC) curves were plotted and the area under ROC curve (C) was used as a measure of discriminatory ability between cases and controls. In subjects without any protective allele, aberrations in one-carbon metabolism showed perfect prediction (C=0.93) while the predictability was lost in subjects with one protective allele (C=0.60). However, predictability increased steadily with increasing number of protective alleles (C=0.63 for 2 protective alleles and C=0.71 for 3 protective alleles). The cut-off point for discrimination was >4 alleles in all predictable combinations. Models of this kind can serve as valuable tools in translational re-search, especially in identifying high-risk individuals and reducing the disease risk either by life style modification or by medical intervention.
Impact of Channel Dynamics, Combined Nonlinearities and ASE Noise on Transmission Performance of all Optical Star WDM Networks  [PDF]
Sridhar Iyer, Shree Prakash Singh
Communications and Network (CN) , 2011, DOI: 10.4236/cn.2011.34028
Abstract: For all optical Wavelength Division Multiplexing (WDM) network based on G.653 fibers, we investigate the quality factor deterioration due to combined nonlinear effects and Amplified spontaneous emission (ASE) noise for system parameters based on ITU-T Recommendation G.692. The investigation: (a) emphasizes on stimulated Raman scattering (SRS) and four wave mixing (FWM) effects which are the dominant nonlinearities known to limit WDM system performance and (b) accounts for beating between nonlinearities and beating between ASE noise and nonlinearities. Using the proposed model, performance of the worst affected channels due to SRS and FWM is compared and the results indicate that the worst affected channel due to SRS performs better and hence must be preferred for reliable and efficient transmission over the worst affected channel due to FWM. Further, the results suggest that to achieve a desired error rate (quality factor); there exists an optimal value of channel spacing for a given number of channels. The proposed theoretical model is also validated through extensive simulations over Rsoft OptSimTM simulator and the two sets of results are found to match, indicating that the proposed model accurately calculates the quality factor of the all optical WDM network.
A Novel Offline PLI-RWA and Hybrid Node Architecture for Zero Blocking and Time Delay Reduction in Translucent Optical WDM Networks  [PDF]
Sridhar Iyer, Shree Prakash Singh
Communications and Network (CN) , 2012, DOI: 10.4236/cn.2012.44036
Abstract: In this paper, we contrive a model that underpins the offline Physical Layer Impairment-Routing and Wavelength Assignment (PLI-RWA) issue in translucent networks. We introduce an innovative PLI-Signal Quality Aware RWA (PLI-SQARWA) algorithm that (a) guarantees zero blocking due to signal degradation and wavelength contention and (b) aims at minimizing the total required number of network components i.e. regenerators and all-optical wavelength converters (AOWCs). Further, in view of reducing the time delay due to optical-electrical-optical (OEO) conversions, we propose a novel electro-optical hybrid translucent node architecture. We show that PLI-SQARWA outperforms a recent heuristic for RWA and regenerator placement (RP) in terms of capital expenditure (CapEx) and time delay; while demonstrating superior blocking performance at all traffic loads. In addition, at high traffic loads, PLI-SQARWA also starts to provision savings on operational expenditure (OpEx). We proceed to the performance comparison of network equipped with the proposed hybrid node and existing translucent and transparent node architectures. The results clearly show that use of the hybrid node incurs less time delay at a similar blocking performance shown by nodes which use OEO conversion for both, regeneration and/or wavelength conversion. The results presented also highlight the significance of equipping the PLI-RWA routing phase with signal quality awareness in order to reduce the network component count and the use of AOWCs to minimize time delay due to OEO conversions.
A Novel Optical Control Plane for Switching an Electro-Optical Hybrid Node in Translucent WDM Optical Networks  [PDF]
Sridhar Iyer, Shree Prakash Singh
Communications and Network (CN) , 2013, DOI: 10.4236/cn.2013.51006

In a translucent network scenario, development of an optical control plane (OCP) that is aware of the location and number of available regenerators and all-optical wavelength converters (AOWCs) is of paramount importance. However, current generalized multiprotocol label switching (GMPLS) protocol suite does not consider the distribution of regenerator and AOWC availability information to all the network nodes. In this paper, we propose a novel optical control plane (OCP) architecture that 1) disseminates information about network components (i.e. regenerators and AOWCs) to all the network nodes, and 2) evaluates candidate routes which use fewest amounts of network components. Performance of the proposed OCP is compared with a recently proposed hybrid OCP approach in terms of blocking performance, number of deployed components and lightpath establishment setup times. The obtained simulation results show that the proposed OCP approach demonstrates low connection blocking and establishes lightpaths by 1) minimizing the overall network cost owing to the deployment of minimum total number of network components, and 2) demonstrating acceptable lightpath establishment setup times at all traffic loads. Further, the proposed OCP methodology is compatible and suitable for controlling the operations of a novel electro-optical hybrid translucent node which is a latency efficient technology capable of delivering a cost effective implementation suitable for large scale deployment.

A Proposal for Mitigating Multiple Black-Hole Attack in Wireless Mesh Networks  [PDF]
Om Shree, Francis J. Ogwu
Wireless Sensor Network (WSN) , 2013, DOI: 10.4236/wsn.2013.54010

The Network Layer in wireless mesh networks is responsible for routing packets making it a prime target for intruders and hackers. Black-hole attack is a type of denial-of-service attack which when carried out can disrupt the services of this layer. This paper takes a look at some important detection and mitigation techniques and presents the drawbacks. After analysis of current mechanisms, the paper proposes RID-AODV, a security solution for multiple black-hole attack in wireless mesh networks. Based on the backbone of AODV, RID-AODV combines the ability of route skipping of IDSAODV and route failure correction using reverse route establishment of RAODV. The enhanced protocol RID-AODV, AODV, IDSAODV, and RAODV are implemented in a simulated environment using ns-2.35 simulator. The networks for each protocol are bombarded with up to ten black-hole nodes starting from zero. The results obtained are then analyzed and compared and a discussion is presented.

Shree Om,Mohammad Talib
International Journal of Digital Information and Wireless Communications , 2011,
Abstract: Wireless Ad-hoc Network is a temporary and decentralized type of wireless network. Due to security vulnerabilities in the routing protocol currently, this type of network is unprotected to network layer attacks. Black-hole attack is such a type of attack and is a Denial-of-Service (DoS) attack. Due to its nature, the attack makes the source node send all the data packets to a Black-hole node that ends up dropping all the packets. The aim of this paper is to reflect light on the severe effects of a Black-hole attack in a Wireless Ad-hoc network and the drawbacks of the security mechanisms being used for the mitigation of this attack.
A report on the antioxidant activity of the powder of the entire plant of Phyllanthus reticulatus Poir
Maruthappan V,Shree K
International Journal of Green Pharmacy , 2010,
Abstract: In the present study, we determined the antioxidant activity of the entire plant of Phyllanthus reticulatus by performing different in vitro antioxidant assays, including 2,2-Diphenyl-1-Picrylhydrazyl (DPPH) radical scavenging, β-carotene bleaching, superoxide anion radical scavenging, reducing power and metal chelating assay at different concentrations (100, 200 and 400 μg/ml). The entire plant powder of P. reticulatus shows good antioxidant activity of about 90.0% when compared with standard Butylated Hydroxy Toluene (BHT) (85%) at a concentration of 400 μg/ml. Results obtained reveal that methanolic extracts of entire plant of P. reticulatus possess higher antioxidant activity when compared with ethanolic extracts. Thus, this study suggests that P. reticulatus plant can be used as a potent source of natural antioxidants.
Tanu Shree Dahiya
Golden Research Thoughts , 2013, DOI: 10.9780/22315063
Abstract: The conventional approach to Effect of stress at workplace has always overemphasized the impact of stress without really examining in depth the different routes to reducing this stress. The purpose of this research has been to explore if a Positive Psychology based intervention such as Appreciative Inquiry would aid in stress reduction at workplace. In the present study, 90 officials at top and middle level from the Videocon Industries participated in a two-day Appreciative Inquiry workshop. Action Research design was used in the study and nature of Intervention used was Appreciative Inquiry. The hypothesis taken in this particular case was 'A Positive psychology-based intervention, such as Appreciative Inquiry, would reduce stress for those who participated in the study.' To quantitatively measure the effects, the OSI-R PSQ was administered to participants to assess stress levels prior to the intervention. During the course of the current study, Appreciative Inquiry was found to reduce stress levels in all areas vis-à-vis, physical strain, interpersonal strain, vocational strain, and psychological strain listed by the Occupational Stress Inventory areas for the experimental group. Interpersonal strain was seen to be significantly reduced after participation in the Appreciative Inquiry workshop. Hence the research reveals a correlation between a positive psychology-based intervention and reduction of stress in the workplace. Lastly, Appreciative Inquiry has proved to be an effective stress reduction tool which could be used extensively across a variety of workplaces in the future.
Intraocular penetration of carbenicillin gentamicin and chloramphenicol with ′Sauflon 85′ soft contact lenses
Jain M,Lal Shree
Indian Journal of Ophthalmology , 1983,
Effects of Phyllanthus reticulatus on lipid profile and oxidative stress in hypercholesterolemic albino rats
Maruthappan V,Shree K
Indian Journal of Pharmacology , 2010,
Abstract: Objective: This study was designed to investigate the effect of Phyllanthus reticulatus on lipid profile and oxidative stress in hypercholesterolemic albino rats. Materials and Methods: Hypercholesterolemia was induced in albino rats by administration of atherogenic diet for 2 weeks. Experimental rats were divided into different groups: normal, hypercholesterolemic control and P. reticulatus treated (250 and 500 mg/kg body weight doses for 45 days). After the treatment period of 45 th day triglyceride, VLDL-cholesterol, HDL-cholesterol, total cholesterol (TC), LDL-cholesterol and oxidative stress (protein carbonyl) were assayed and compared with hypercholesterolemic control. Results: The aqueous extract of P. reticulatus (250 mg and 500 mg/kg) produced significant reduction (P < 0.05) in triglyceride, VLDL-cholesterol, total cholesterol (TC), LDL-cholesterol and oxidative stress (protein carbonyl) while increased HDL-cholesterol in atherogenic diet-induced hypercholesterolemic rats at the end of the treatment period (45 days). However, the reduction in the above parameters was comparable with hypercholesterolemic control. Thus, aqueous extract of P. reticulatus is effective in controlling TC, lipid profile and oxidative stress in hypercholesterolemic animals. Conclusion: The results suggest the aqueous extract of P. reticulatus can be utilized for prevention of atherosclerosis in hypercholesterolemic patients.

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