18 research outputs found

    Replication in Mobile Ad-hoc Network using Hopfield Network

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    Mobile Ad hoc Network (MANET) is a network comprises of mobile nodes connected without any centralized administration. Each node in the network has the ability to share a large number of objects with other nodes. The nodes are connected with other nodes to forward a message to other nodes until the search for node that desire meets. This paper represents a new replication method to recover the performance in distributed system. Objects are replicated on different nodes in the network to minimize the search for an object. It is observed that mobility of nodes predicted using SOM (Self Organizing Maps) technique provides less accuracy. This paper represents an algorithm that uses the network parameters as input condition to replicate objects into the nodes. The decision for each node will be taken by gathering the input conditions and feed to the Hopfield Neural Network. It is view that it will provide more accuracy and improve the performance

    Application of a targeted-enrichment methodology for full-genome sequencing of Dengue 1-4, Chikungunya and Zika viruses directly from patient samples.

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    The frequency of epidemics caused by Dengue viruses 1-4, Zika virus and Chikungunya viruses have been on an upward trend in recent years driven primarily by uncontrolled urbanization, mobility of human populations and geographical spread of their shared vectors, Aedes aegypti and Aedes albopictus. Infections by these viruses present with similar clinical manifestations making them challenging to diagnose; this is especially difficult in regions of the world hyperendemic for these viruses. In this study, we present a targeted-enrichment methodology to simultaneously sequence the complete viral genomes for each of these viruses directly from clinical samples. Additionally, we have also developed a customized computational tool (BaitMaker) to design these enrichment baits. This methodology is robust in its ability to capture diverse sequences and is amenable to large-scale epidemiological studies. We have applied this methodology to two large cohorts: a febrile study based in Colombo, Sri Lanka taken during the 2009-2015 dengue epidemic (n = 170) and another taken during the 2016 outbreak of Zika virus in Singapore (n = 162). Results from these studies indicate that we were able to cover an average of 97.04% ± 0.67% of the full viral genome from samples in these cohorts. We also show detection of one DENV3/ZIKV co-infected patient where we recovered full genomes for both viruses

    AN INVESTIGATION OF THE ROLE OF FC GAMMA RECEPTORS IN DENGUE VIRUS NEUTRALIZATION

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    Ph.DDOCTOR OF PHILOSOPH

    Adenovirus-vectored vaccines

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    Background: Engineered adenoviruses are being increasingly explored as immunoprophylactic or immunotherapeutic vaccine vectors. Encouraging data from preclinical studies using human adenovirus vectors carrying different antigen genes have resulted in many currently ongoing clinical trials. Objective: The article seeks to review the current status of the use of adenoviruses as vaccine vectors. Methods: This review is based on the patent literature since 2000 pertaining to the development of adenovirus vaccine vectors for infectious and non-infectious diseases. Conclusion: Human adenovirus-vectored vaccines have important limitations that stem from their immunogenicity and restrict their utility. This has spurred intensive efforts to find alternative adenovirus vectors and strategies, each with its own advantages and shortcomings

    The prevalence of antibodies to adenovirus serotype 5 in an adult Indian population and implications for adenovirus vector vaccines

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    In vivo gene delivery using human adenovirus serotype 5 (AdV5) vectors is being explored for vaccination purposes. The presence of anti-AdV5 antibodies in human serum arising from natural exposure to AdV5 can interfere potentially with and compromise the efficacy of rAdV5-based vaccine vectors. In this report, a collection of 114 sera from healthy adult Indian blood donors was analyzed for the presence of anti-AdV5 antibodies, using an AdV5 vector encoding the Green Fluorescent Protein (GFP) to monitor the presence of anti-AdV5 neutralizing antibodies in human sera based on their ability to block virus entry into HeLa cells which express the Coxsackievirus-and-Adenovirus Receptor (CAR). In this assay all samples tested were positive for anti-AdV5 antibodies, with titers varying over a very wide range. It was also observed that these antibodies facilitated the uptake of the reporter AdV5 vector into the monocytic cell line U937 which does not express CAR, but expresses Fc receptors (FcRs) instead. These observations have implications for rAdV5-based vaccine development

    A Comprehensive Review of Microbial Contamination in the Indoor Environment: Sources, Sampling, Health Risks, and Mitigation Strategies

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    The quality of the indoor environment significantly impacts human health and productivity, especially given the amount of time individuals spend indoors globally. While chemical pollutants have been a focus of indoor air quality research, microbial contaminants also have a significant bearing on indoor air quality. This review provides a comprehensive overview of microbial contamination in built environments, covering sources, sampling strategies, and analysis methods. Microbial contamination has various origins, including human occupants, pets, and the outdoor environment. Sampling strategies for indoor microbial contamination include air, surface, and dust sampling, and various analysis methods are used to assess microbial diversity and complexity in indoor environments. The review also discusses the health risks associated with microbial contaminants, including bacteria, fungi, and viruses, and their products in indoor air, highlighting the need for evidence-based studies that can relate to specific health conditions. The importance of indoor air quality is emphasized from the perspective of the COVID-19 pandemic. A section of the review highlights the knowledge gap related to microbiological burden in indoor environments in developing countries, using India as a representative example. Finally, potential mitigation strategies to improve microbiological indoor air quality are briefly reviewed

    Dengue virus neutralization in cells expressing Fc gamma receptors.

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    Activating Fc gamma receptors (FcγRs) in hematopoietic cells serve to remove antibody-opsonized antigens, including dengue virus (DENV), from systemic circulation. While neutralizing antibody concentrations provide humoral immunity, cross-reactive or sub-neutralizing levels of antibody can result in antibody-dependent enhancement of DENV infection that increases overall viral burden. Recently, it has been suggested that the antibody levels needed for DENV neutralization differs when different FcγR is engaged. If this is true, the threshold titer used to infer immunity should be influenced by FcγR usage. Here, using cells that express both activating and inhibitory FcγRs, we show that the type of FcγR engaged during phagocytosis can influence the antibody concentration requirement for DENV neutralization. We demonstrate that phagocytosis through FcγRI requires significantly less antibody for complete DENV neutralization compared to FcγRIIA. Furthermore, when DENV is opsonized with sub-neutralizing levels of antibody, FcγRI-mediated phagocytosis resulted in significantly reduced DENV titers compared to FcγRIIA. However, while FcγRI may remove antibody-opsonized DENV more efficiently, this receptor is only preferentially engaged by clustering when neutralizing, but not sub-neutralizing antibody concentrations, were used. Collectively, our study demonstrates that activating FcγR usage may influence antibody titers needed for DENV neutralization
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