86 research outputs found

    Spectral analysis for compressible quantum fluids

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    Turbulent fluid dynamics typically involves excitations on many different length scales. Classical incompressible fluids can be cleanly represented in Fourier space enabling spectral analysis of energy cascades and other turbulence phenomena. In quantum fluids, additional phase information and singular behaviour near vortex cores thwarts the direct extension of standard spectral techniques. We develop a formal and numerical spectral analysis for U(1)U(1) symmetry-breaking quantum fluids suitable for analyzing turbulent flows, with specific application to the Gross-Pitaevskii fluid. Our analysis builds naturally on the canonical approach to spectral analysis of velocity fields in compressible quantum fluids, and establishes a clear correspondence between energy spectral densities, power spectral densities, and autocorrelation functions, applicable to energy residing in velocity, quantum pressure, interaction, and potential energy of the fluid. Our formulation includes all quantum phase information and also enables arbitrary resolution spectral analysis, a valuable feature for numerical analysis. A central vortex in a trapped planar Bose-Einstein condensate provides an analytically tractable example with spectral features of interest in both the infrared and ultraviolet regimes. Sampled distributions modelling the dipole gas, plasma, and clustered regimes exhibit velocity correlation length increasing with vortex energy, consistent with known qualitative behaviour across the vortex clustering transition. The spectral analysis of compressible quantum fluids presented here offers a rigorous tool for analysing quantum features of superfluid turbulence in atomic or polariton condensates.Comment: 17 pages. Fixed error in appendix C presentation, added references. Results and conclusions unchange

    Immune Responses to Defined Plasmodium Falciparum Antigens and Disease Susceptibility in Two Subpopulations of Northern India

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    The aim of this study was to investigate the prevalence of naturally acquired immune response to malaria in individuals of different age groups belonging to areas of northern India, Loni PHC (LN) and Dhaulana PHC (SD) of district Ghaziabad. Plasmodium falciparum-infected erythrocyte lysate and six synthetic peptides from different stages of P. falciparum (CSP, MSP1, AMA1, RAP1, EBA175 and PfG27) were used to determine both humoral and cellular immune responses. Plasma of individual subject was also analyzed for IL-4, IL-10, IFN-γ and TNF-α level. We observed an age-wise increasing trend of immunity in these two populations. There was a significant association between the number of antibody responders and recognition of stage-specific epitopes by antibodies. Peripheral blood mononuclear cells of more than 75% of individuals proliferated in response to stimulation by all the antigens in LN area. IL-4 and IL-10 responses were significantly higher in individuals of LN Area; whereas IFN-g and   TNF-a responses were higher in individuals of SD Area. It was also noticed that the frequency of responders to stage-specific antigens was higher in individuals from the LN area where the frequency of malaria was lower. The naturally acquired immune responses to P. falciparum antigens reflected the reduced risk of malaria in the study groups. The results demonstrated immunogenicity of the epitopes to P. falciparum in population of this endemic zone

    Isolation and Purification of C-phycocyanin From Nostoc Muscorum (Cyanophyceae and Cyanobacteria) Exhibits Antimalarial Activity in Vitro

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    The phycobilin pigments are intensively fluorescent and water soluble. They are categorized into three types, such as pigments containing high, intermediate and low energies are phycoerythrins (phycoerythrocyanins), phycocyanins and allophycocyanins, respectively. Besides light harvesting, the phycobiliproteins have shown industrial and biomedical importance. Among them, C-phycocyanin (C-PC) has been considered to be the most preferred one. The present study was undertaken to evaluate the antimalarial activity of C-PC isolated from a nitrogen-fixing cyanobacterium and Nostoc muscorum. C-PC was extracted and purified by acetone extraction and ammonium sulfate precipitation and dialysis followed by amicon filtration. It was isolated as a~124 kDa water soluble protein molecule. It showed antimalarial activity in vitro against chloroquine sensitive and resistant Plasmodium falciparum strains. Inhibitory concentrations at 50%, 90% and 95% were determined as 10.27±2.79, 53.53±6.26 and 73.78±6.92 µg/ml against the chloroquine-sensitive strains; 10.37±1.43, 56.99±11.07 and 72.79±8.59 µg/ml against chloroquine resistant of Plasmodium falciparum strains. C-PC was found to have antimalarial activity even at a concentration of 3.0µg/ml. The possible mechanism might be relied on the destruction of polymerization of haemozoin by binding of C-PC with ferriprotoporphyrin-IX at the water surface of the plasma membrane

    Isolation and Purification of C-phycocyanin From Nostoc Muscorum (Cyanophyceae and Cyanobacteria) Exhibits Antimalarial Activity in Vitro

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    The phycobilin pigments are intensively fluorescent and water soluble. They are categorized into three types, such as pigments containing high, intermediate and low energies are phycoerythrins (phycoerythrocyanins), phycocyanins and allophycocyanins, respectively. Besides light harvesting, the phycobiliproteins have shown industrial and biomedical importance. Among them, C-phycocyanin (C-PC) has been considered to be the most preferred one. The present study was undertaken to evaluate the antimalarial activity of C-PC isolated from a nitrogen-fixing cyanobacterium and Nostoc muscorum. C-PC was extracted and purified by acetone extraction and ammonium sulfate precipitation and dialysis followed by amicon filtration. It was isolated as a~124 kDa water soluble protein molecule. It showed antimalarial activity in vitro against chloroquine sensitive and resistant Plasmodium falciparum strains. Inhibitory concentrations at 50%, 90% and 95% were determined as 10.27±2.79, 53.53±6.26 and 73.78±6.92 µg/ml against the chloroquine-sensitive strains; 10.37±1.43, 56.99±11.07 and 72.79±8.59 µg/ml against chloroquine resistant of Plasmodium falciparum strains. C-PC was found to have antimalarial activity even at a concentration of 3.0µg/ml. The possible mechanism might be relied on the destruction of polymerization of haemozoin by binding of C-PC with ferriprotoporphyrin-IX at the water surface of the plasma membrane

    Development of Design Tool for Design of Steel Columns

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    The design methodology based on Limit State Method involves numerous equations and parameters, which makes the design process a complex and tedious task. Also design being a trial and error process is very repetitive in nature. Hence use of spreadsheets can reduce the time and effort of a designer/engineer considerably. Because of the compactness and flexibility, spreadsheets have become one of the best choices for an engineer, despite the availability of number of mainstream design software packages. Even though development of spreadsheets are very common now-a-days, not many of them includes a detailed design procedure for multiple international codes. So the main aim of this project is to prepare a Microsoft Excel Spreadsheet which will entail a detailed design of Steel Columns for three different steel codes. The three steel codes being the Indian Steel Code (IS 800-2007), the British Steel Code (BS 5950-2000) and the American Steel Code (AISC 360-2010). The result of this project will be a design tool, which can be conveniently used by an engineer to check the design status of an column section and to strike a balance between safety and economy

    Statistical optimization for lipase production from solid waste of vegetable oil industry

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    <p>The production of biofuel using thermostable bacterial lipase from hot spring bacteria out of low-cost agricultural residue olive oil cake is reported in the present paper. Using a lipase enzyme from <i>Bacillus licheniformis</i>, a 66.5% yield of methyl esters was obtained. Optimum parameters were determined, with maximum production of lipase at a pH of 8.2, temperature 50.8°C, moisture content of 55.7%, and biosurfactant content of 1.693 mg. The contour plots and 3D surface responses depict the significant interaction of pH and moisture content with biosurfactant during lipase production. Chromatographic analysis of the lipase transesterification product was methyl esters, from kitchen waste oil under optimized conditions, generated methyl palmitate, methyl stearate, methyl oleate, and methyl linoleate.</p

    Investigation of chirality in the case of 102Rh

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    Excited states in 102Rh were populated in the fusion-evaporation reaction 94Zr(11B, 3n)102Rh at a beam energy of 36 MeV using the INGA spectrometer at IUAC, New Delhi. The angular correlations and the electromagnetic character of some of the gamma-ray transitions observed were investigated in details. A new chiral candidate sister band was found. Lifetimes of exited states in 102Rh were measured using the Doppler-shift attenuation technique and the derived reduced transition probabilities are compared to the predictions of the Two Quasiparticles Plus Triaxial Rotor model

    Murid Herpesvirus-4 Exploits Dendritic Cells to Infect B Cells

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    Dendritic cells (DCs) play a central role in initiating immune responses. Some persistent viruses infect DCs and can disrupt their functions in vitro. However, these viruses remain strongly immunogenic in vivo. Thus what role DC infection plays in the pathogenesis of persistent infections is unclear. Here we show that a persistent, B cell-tropic gamma-herpesvirus, Murid Herpesvirus-4 (MuHV-4), infects DCs early after host entry, before it establishes a substantial infection of B cells. DC-specific virus marking by cre-lox recombination revealed that a significant fraction of the virus latent in B cells had passed through a DC, and a virus attenuated for replication in DCs was impaired in B cell colonization. In vitro MuHV-4 dramatically altered the DC cytoskeleton, suggesting that it manipulates DC migration and shape in order to spread. MuHV-4 therefore uses DCs to colonize B cells

    Potential therapeutic applications of microbial surface-activecompounds

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    Numerous investigations of microbial surface-active compounds or biosurfactants over the past two decades have led to the discovery of many interesting physicochemical and biological properties including antimicrobial, anti-biofilm and therapeutic among many other pharmaceutical and medical applications. Microbial control and inhibition strategies involving the use of antibiotics are becoming continually challenged due to the emergence of resistant strains mostly embedded within biofilm formations that are difficult to eradicate. Different aspects of antimicrobial and anti-biofilm control are becoming issues of increasing importance in clinical, hygiene, therapeutic and other applications. Biosurfactants research has resulted in increasing interest into their ability to inhibit microbial activity and disperse microbial biofilms in addition to being mostly nontoxic and stable at extremes conditions. Some biosurfactants are now in use in clinical, food and environmental fields, whilst others remain under investigation and development. The dispersal properties of biosurfactants have been shown to rival that of conventional inhibitory agents against bacterial, fungal and yeast biofilms as well as viral membrane structures. This presents them as potential candidates for future uses in new generations of antimicrobial agents or as adjuvants to other antibiotics and use as preservatives for microbial suppression and eradication strategies
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