2,336 research outputs found
Levy statistical fluctuations from a Random Amplifying Medium
We report the studies of emission from a novel random amplifying medium that
we term a ``Levy Laser'' due to the non-Gaussian statistical nature of its
emission over the ensemble of random realizations. It is observed that the
amplification is dominated by certain improbable events that are ``larger than
rare'', which give the intensity statistics a Levy like ``fat tail''. This, to
the best of our knowledge, provides the first experimental realization of Levy
flight in optics in a random amplifying medium.Comment: 22 pages, 14 figures (postscript format
Biofiltration of Volatile organic compounds Using Chir Pine Cone Nuts Inoculated with Pseudomonas putida
Volatile organic compounds (VOCs) and hazardous air pollutants (HAPs) are the major pollutants in industrial and agricultural emissions. This study targets the efficiency and applicability of biofiltration to remove methanol and n-hexane, two common air pollutants, using Chir pine cone nuts as filter media and Pseudomonas putida as the inoculant. The designed biofilter was operated between 25-35°C, with an airflow rate of 0.35 m3 h-1 and nutrient supply of 1-2 L Day-1. From a 60-day operating period, methanol's removal efficiency was higher than n-hexane, with a maximum removal efficiency of 93.91% achieved at an inlet loading rate of 101.39 g m-3h-1 for methanol and 87.96% at 398.46 g m-3h-1 for n-hexane. The effects of varying loading rates on the elimination capacity for both pollutants were also studied. In addition, the temperature profile of the biofilter, microbial analysis, and the BOD concentration of leachate was also studied during the operation period. The findings offer insights into the potential use of Chir pine nuts as filter media for the biodegradation of methanol and n-hexane and provide a foundation for future research to optimize the biofilter system's design and operation to increase its removal efficiency of other contaminants
Regulation of Pancreatic α and β Cell Function by the Bile Acid Receptor TGR5
The discovery that bile acids act as endogenous ligands of the membrane receptor TGR5 and the nuclear receptor FXR increased their significance as regulators of cholesterol, glucose and energy metabolism. Activation of TGR5, expressed on enteroendocrine L cells, by bile acids caused secretion of GLP-1, which stimulates insulin secretion from pancreatic β cells. Expression of TGR5 on pancreatic islet cells and the direct effect of bile acids on the endocrine functions of pancreas, however, are not fully understood. The aim of this study was to identify expression of TGR5 in pancreatic islet cells and determine the effect of bile acids on insulin secretion. Expression of TGR5 was identified by quantitative PCR and western blot in islets from human and mouse, and in α (αTC1-6) and β (MIN6) cells. Release of insulin, glucagon and GLP-1 were measured by ELISA. The signaling pathways coupled to TGR5 activation were identified by direct measurements such as stimulation of G proteins, adenylyl cyclase activity, PI hydrolysis and intracellular Ca2+ in response to bile acids; and confirmed by the use of selective inhibitors that block specific steps in the signaling pathway. Our studies identified expression of TGR5 receptors in β cells and demonstrated that activation of these receptors by both pharmacological ligands (oleanolic acid (OA) and INT-777) and physiological ligand (lithocholic acid, LCA) induced insulin secretion. TGR5 receptors are also expressed in α cells and, activation of TGR5 by OA, INT-777 and LCA at 5 mM glucose induced release of glucagon, which is processed from proglucagon by the selective expression of prohormone convertase 2 (PC2). However, under hyperglycemia, activation of TGR5 in α cells augmented the glucose-induced increase in GLP-1 secretion, which in turn, stimulated insulin secretion. Secretion of GLP-1 from α cells reflected TGR5-mediated increase in PC1 promoter activity and PC1 expression, which selectively converts proglucagon to GLP-1. The signaling pathway activated by TGR5 to mediate insulin and GLP-1 secretion involved Gs/cAMP/Epac/PLC-ε/Ca2+. These results provide insights into the mechanisms involved in the regulation of pancreatic α and β cell function by bile acids and may lead to new therapeutic avenues for the treatment of diabetes
An Effective Private Data storage and Retrieval System using Secret sharing scheme based on Secure Multi-party Computation
Privacy of the outsourced data is one of the major challenge.Insecurity of
the network environment and untrustworthiness of the service providers are
obstacles of making the database as a service.Collection and storage of
personally identifiable information is a major privacy concern.On-line public
databases and resources pose a significant risk to user privacy, since a
malicious database owner may monitor user queries and infer useful information
about the customer.The challenge in data privacy is to share data with
third-party and at the same time securing the valuable information from
unauthorized access and use by third party.A Private Information Retrieval(PIR)
scheme allows a user to query database while hiding the identity of the data
retrieved.The naive solution for confidentiality is to encrypt data before
outsourcing.Query execution,key management and statistical inference are major
challenges in this case.The proposed system suggests a mechanism for secure
storage and retrieval of private data using the secret sharing technique.The
idea is to develop a mechanism to store private information with a highly
available storage provider which could be accessed from anywhere using queries
while hiding the actual data values from the storage provider.The private
information retrieval system is implemented using Secure Multi-party
Computation(SMC) technique which is based on secret sharing. Multi-party
Computation enable parties to compute some joint function over their private
inputs.The query results are obtained by performing a secure computation on the
shares owned by the different servers.Comment: Data Science & Engineering (ICDSE), 2014 International Conference,
CUSA
Synthesis of Al and Ag nanoparticles through ultra-sonic dissociation of thermal evaporation deposited thin films for promising clinical applications as polymer nanocomposite
Nanoparticles (NPs) having well-defined shape, size and clean surface serve as ideal model system to investigate surface/interfacial reactions. Ag and Al NPs are receiving great interest due to their wide applications in bio-medical field, aerospace and space technology as combustible additives in propellants and hydrogen generation. Hence, in this study, we have synthesized Ag and Al NPs using an innovative approach of ultra-sonic dissociation of thin films. Phase and particle size distributions of the Ag and Al NPs have been determined by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Thin film dissociation/dissolution mechanism, hence conversion into NPs has been characterized by SEM- scanning electron microscope. EDXA & ICPMS have been performed for chemical analysis of NPs. Optical properties have been characterized by UV-Vis and PL spectroscopy. These NPs have also been investigated for their anti-bacterial activity against Escherichia coli bacteria. To the best of our knowledge, this is the first time when NPs has been synthesized by ultra-sonic dissociation of thin films. As an application, these NPs were used further for synthesis of nanocomposite polymer membranes, which show excellent activity against bio film formation
The underexploited biotechnology of overexploited Origanum species: Status, knowledge gaps, prospects and potential
The genus Origanum is a group of phytochemically diverse, aromatic species. Distributed mainly in Eurasia and Mediterranean, they are used in traditional medicine, cosmetics and for culinary purposes. They possess antiproliferative, antioxidant, antiviral, antiseptic, anti-inflammatory, anti-hypertensive properties. The major constituents of Origanum spp. are carvacrol and/or thymol together with ?-terpinene, p-cymene, linalool, terpinene-4-ol and sabinene hydrate. Several flavonoids and glycosides are also found. Although the Origanum spp. can either be cultivated or sourced from nature, high demand has necessitated increased production. Overexploitation from natural habitat has threatened these species. Also, due to its poor viability and small-sized seeds, cross-pollination abilities, less productive vegetative propagation, climate-dependent conventional propagation, its genetic improvement has been limited and thus scientific management of available germplasms through biotechnological approach is necessary. For in-vitro propagation, the literature review showed significant differences in culture protocols, genotypes and their success rates. Studies reported cell culture-based production of secondary metabolites or isolation of active compounds in different species of Origanum, which show antiproliferative activity in cancerous cell lines. However, significant knowledge gaps exist. The urgent need is to use advance technologies in enhancing either plant propagation thus the production of source material for active constituents or for genetic improvement of Origanum germplasms for contents, as well as to validate the therapeutic potential of Origanum constituents. This review critically appraises the status of mostly underexploited biotechnological know-how and research on highly valued medicinal herbs, Origanum and throws light on prospects and potential
Efficacy of intralesional corticosteroid versus autologous platelet rich plasma injection in the management of chronic plantar fasciitis
Background: Plantar fasciitis is a common pathological condition affecting the hind foot, and a common cause of heel pain. The present study was taken up to assess the efficacy of intralesional corticosteroid compared to autologous platelet rich plasma injection in the management of chronic plantar fasciitis.Methods: Patients were randomized into two groups (Group A and Group B) of 30 each. Group-A received Corticosteroid injection while Group-B received PRP injection. Patients were assessed functionally using American Orthopaedic Foot and ankle score (AOFAS), Visual analogue scale (VAS) scores before treatment and on follow-up visit at 6 weeks, 3rd month, and 6th month. Ultrasound of heel for plantar fascia thickness was measured before treatment and follow up visit at 6th month.Results: A significant decrease in VAS score was observed in the corticosteroid group compared to PRP group at 6 weeks while the VAS score continued to decrease in the PRP group at 3 months and 6 months with an increase in the corticosteroid group at 3 months and 6 months. A significant increase in AOFAS was observed in the Corticosteroid group compared to PRP group at 6 weeks which increased in the PRP group at 3 months and 6 months. However it decreased in the corticosteroid group at 3 months and 6 months. Ultrasonographic evaluation showed improvement in fascial thickness in both the groups, but was better in the PRP group.Conclusions: To conclude our study shows that corticosteroid is more effective for short term relief and PRP is more effective for long term relief
Design of Reversible Even and Odd Parity Generator and Checker Using Multifunctional Reversible Logic Gate (MRLG)
Digital data transmission made more efficient of communication. For error free transmission in the digital communication at the source end used parity generator and at destination used parity checker. This paper proposed design of 3 bit reversible Even and Odd parity generator and checker using the multifunctional reversible logic gate (MRLG). The proposed design is designed and simulated using cadence software
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