1,008 research outputs found

    Faraday Effect in Molecules

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    Robustness of Planar Fourier Capture Arrays to Colour Changes and Lost Pixels

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    Planar Fourier capture arrays (PFCAs) are optical sensors built entirely in standard microchip manufacturing flows. PFCAs are composed of ensembles of angle sensitive pixels (ASPs) that each report a single coefficient of the Fourier transform of the far-away scene. Here we characterize the performance of PFCAs under the following three non-optimal conditions. First, we show that PFCAs can operate while sensing light of a wavelength other than the design point. Second, if only a randomly-selected subset of 10% of the ASPs are functional, we can nonetheless reconstruct the entire far-away scene using compressed sensing. Third, if the wavelength of the imaged light is unknown, it can be inferred by demanding self-consistency of the outputs.Comment: 15 pages including cover page, 12 figures, associated with the 9th International Conference on Position Sensitive Detector

    Factors influencing theengraftment of haematopoietic stem cell transplantion in patients with hematological malignancy

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    Haematopoietic stem cell transplantation remains the only curative option for many haematological malignancies. Currently, the majority of procedures for procurement of haematopoietic progenitor cells are performed by peripheral blood apheresis collection. The development of apheresis technology, the discovery of haematopoietic growth factors and small molecule CXCR4 antagonist for stem- cell mobilization and in vivo experimental transplantation studies that eventually led to clinical PBSCT. The quality of PBSC graft be assessed by its speed of engraftment. The advantage of early engraftment of haematopoietic stem cell transplantation include, reduced incidence of post transplant neutropenia associated infections, mortality, morbidity and shorten the length of hospital stay that eventually reduce the overall cost. Furthermore this valuable expensive procedure will be available for more number of patients who are waiting for their disease to be cured. This prospective observational study was undertaken to study (favorable and unfavorable) factors influencing the HSC engraftment. Since early engraftment reduces length of hospital stay, morbidity, mortality and cost of this highly expensive treatment, it is imperative to utilize all available options to enhance the speed of engraftment. In a country like India where there are a few established haematopoietic stem cell transplantation centers available, there are many patients desperately waiting for their life to be saved by this specialized procedure. Hence, successful and faster PBSC graft engraftment is absolutely essential

    ASPERGILLUS FLAVUS MEDIATED SILVER NANOPARTICLES SYNTHESIS AND EVALUATION OF ITS ANTIMICROBIAL ACTIVITY AGAINST DIFFERENT HUMAN PATHOGENS

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    Objective: Here, we report the extracellular synthesis of silver nanoparticles (AgNPs) using the cell-free extract of fungal isolate Aspergillus flavus and evaluation its inhibitory activity against bacterial pathogens. Methods: Synthesized AgNPs was characterized via high throughput instrumentation such as UV–Visible spectrophotometer (UV-Vis) and Fourier transform infrared spectroscopy, High-resolution transmission electron microscopy (HRTEM), X-ray Diffraction (XRD) and Energy dispersive X-ray spectroscopy (EDAX). Results: Formation of yellowish brown colour clearly indicates the synthesis of AgNPs which produces a SPR peak at 420 nm. Active protein metabolites present in the cell-free extract plays a crucial role in reduction and stabilization of AgNPs. It was clearly observed that synthesized AgNPs were faced-centered cubic crystalline in nature with the mean size of 22±11 nm. Further, synthesized AgNPs capped with protein moieties exhibits excellent inhibitory activity against tested bacterial pathogens. Conclusion: In this study, we have isolated the fungal strain A. flavus from the infected larvae of D. eucharis from the soil. The active metabolites of isolated A. flavus have been successfully used as an eco-friendly reducing agent to generate AgNPs and synthesized particles can be potentially developed as a drug candidature for antimicrobial therapy

    Impact of riparian land use on stream insects of Kudremukh National Park, Karnataka state, India

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    The impact of riparian land use on the stream insect communities was studied at Kudremukh National Park located within Western Ghats, a tropical biodiversity hotspot in India. The diversity and community composition of stream insects varied across streams with different riparian land use types. The rarefied family and generic richness was highest in streams with natural semi evergreen forests as riparian vegetation. However, when the streams had human habitations and areca nut plantations as riparian land use type, the rarefied richness was higher than that of streams with natural evergreen forests and grasslands. The streams with scrub lands and iron ore mining as the riparian land use had the lowest rarefied richness. Within a landscape, the streams with the natural riparian vegetation had similar community composition. However, streams with natural grasslands as the riparian vegetation, had low diversity and the community composition was similar to those of paddy fields. We discuss how stream insect assemblages differ due to varied riparian land use patterns, reflecting fundamental alterations in the functioning of stream ecosystems. This understanding is vital to conserve, manage and restore tropical riverine ecosystems

    The Structure of High Strehl Ratio Point-Spread Functions

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    We describe the symmetries present in the point-spread function (PSF) of an optical system either located in space or corrected by an adaptive o to Strehl ratios of about 70% and higher. We present a formalism for expanding the PSF to arbitrary order in terms of powers of the Fourier transform of the residual phase error, over an arbitrarily shaped and apodized entrance aperture. For traditional unapodized apertures at high Strehl ratios, bright speckles pinned to the bright Airy rings are part of an antisymmetric perturbation of the perfect PSF, arising from the term that is first order in the residual phase error. There are two symmetric second degree terms. One is negative at the center, and, like the first order term, is modulated by the perfect image's field strength -- it reduces to the Marechal approximation at the center of the PSF. The other is non-negative everywhere, zero at the image center, and can be responsible for an extended halo -- which limits the dynamic range of faint companion detection in the darkest portions of the image. In regimes where one or the other term dominates the speckles in an image, the symmetry of the dominant term can be exploited to reduce the effect of those speckles, potentially by an order of magnitude or more. We demonstrate the effects of both secondary obscuration and pupil apodization on the structure of residual speckles, and discuss how these symmetries can be exploited by appropriate telescope and instrument design, observing strategies, and filter bandwidths to improve the dynamic range of high dynamic range AO and space-based observations. Finally, we show that our analysis is relevant to high dynamic range coronagraphy.Comment: Accepted for publication in ApJ; 20 pages, 4 figure

    On the influence of spatial heterogeneity on an internal boundary layer at a short fetch

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    Surface layer meteorological data collected at a coastal site, at Vasco-Da-Gama (15°21′N, 73°51′E, 58.5m MSL) (13–18 July, 2002) with prevailing southwesterly surface winds are analyzed to study the characteristics of internal boundary layer at a short fetch using an instrumented tower (9 m). The spectral and turbulence characteristics of wind are compared with earlier measurements made at a comparatively homogeneous terrain and the standards available in literature. The study show the smaller eddies in the vertical velocity spectrum attains equilibrium with the underlying surface at a short fetch itself and follows spectral similarity. However, this is not followed by longitudinal and transverse velocity spectra under unstable as well as stable condition

    NEIGHBORHOOD-BASED APPROACH OF COLLABORATIVE FILTERING TECHNIQUES FOR BOOK RECOMMENDATION SYSTEM

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    Recommendation System or Recommender System help the user to predict the "rating" or "preference" a user would give to an item. Recommender systems in general helps the users to find content, products, or services (such as digital products, books, music, movie, TV programs, and web sites) by combining and analyzing suggestions from other users, which mean rating from various people, and users. These recommendation systems use analytic technology to calculate the results that a user is willing to purchase, and the users will receive recommendations to a product of their interest. The aim of the System is to provide a recommendation based on users likes or reviews or ratings. Recommendation system comprises of content based and collaborative based filtering techniques. In this paper, collaborative based filtering has been used to get the expected outcome. The expected outcome has been achieved through collaborative filtering with the help of correlation techniques which in turn comprises of Pearson correlation, cosine similarity, Kendall’ s Tau correlation, Jaccard similarity, Spearman Rank Correlation, Mean-squared distance, etc. This paper tells about which similarity metrics such us Pearson correlation (PC), constrained Pearson correlation (CPC), spearman rank correlation (SRC) which is good in the context of book recommendation system and then applied with neighborhood algorithm

    NEIGHBORHOOD-BASED APPROACH OF COLLABORATIVE FILTERING TECHNIQUES FOR BOOK RECOMMENDATION SYSTEM

    Get PDF
    Recommendation System or Recommender System help the user to predict the "rating" or "preference" a user would give to an item. Recommender systems in general helps the users to find content, products, or services (such as digital products, books, music, movie, TV programs, and web sites) by combining and analyzing suggestions from other users, which mean rating from various people, and users. These recommendation systems use analytic technology to calculate the results that a user is willing to purchase, and the users will receive recommendations to a product of their interest. The aim of the System is to provide a recommendation based on users likes or reviews or ratings. Recommendation system comprises of content based and collaborative based filtering techniques. In this paper, collaborative based filtering has been used to get the expected outcome. The expected outcome has been achieved through collaborative filtering with the help of correlation techniques which in turn comprises of Pearson correlation, cosine similarity, Kendall’ s Tau correlation, Jaccard similarity, Spearman Rank Correlation, Mean-squared distance, etc. This paper tells about which similarity metrics such us Pearson correlation (PC), constrained Pearson correlation (CPC), spearman rank correlation (SRC) which is good in the context of book recommendation system and then applied with neighborhood algorithm

    Developing procedures for assessment of ecological status of Indian River basins in the context of environmental water requirements

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    River basins / Ecology / Indicators / Environmental flows / Environmental management / Habitats / Biota / Fish / Ecosystems / India / Krishna River Basin / Chauvery River Basin / Narmada River Basin / Periyar River Basin / Ganga River Basin
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