6,964 research outputs found

    PONDER - A Real time software backend for pulsar and IPS observations at the Ooty Radio Telescope

    Full text link
    This paper describes a new real-time versatile backend, the Pulsar Ooty Radio Telescope New Digital Efficient Receiver (PONDER), which has been designed to operate along with the legacy analog system of the Ooty Radio Telescope (ORT). PONDER makes use of the current state of the art computing hardware, a Graphical Processing Unit (GPU) and sufficiently large disk storage to support high time resolution real-time data of pulsar observations, obtained by coherent dedispersion over a bandpass of 16 MHz. Four different modes for pulsar observations are implemented in PONDER to provide standard reduced data products, such as time-stamped integrated profiles and dedispersed time series, allowing faster avenues to scientific results for a variety of pulsar studies. Additionally, PONDER also supports general modes of interplanetary scintillation (IPS) measurements and very long baseline interferometry data recording. The IPS mode yields a single polarisation correlated time series of solar wind scintillation over a bandwidth of about four times larger (16 MHz) than that of the legacy system as well as its fluctuation spectrum with high temporal and frequency resolutions. The key point is that all the above modes operate in real time. This paper presents the design aspects of PONDER and outlines the design methodology for future similar backends. It also explains the principal operations of PONDER, illustrates its capabilities for a variety of pulsar and IPS observations and demonstrates its usefulness for a variety of astrophysical studies using the high sensitivity of the ORT.Comment: 25 pages, 14 figures, Accepted by Experimental Astronom

    Method of producing water-soluble glucuronic acid derivatives of vitamin A

    Get PDF
    Water soluble glucuronic acid derivatives of vitamin A, including retinoyl β-glucuronide and retinyl β-glucuronide, having in vivo activity comparable to retinoicacid and retinol and methods of their preparation are disclosed

    Implications of sterile neutrinos for medium/long-baseline neutrino experiments and the determination of θ13\theta_{13}

    Full text link
    We revisit some of the recent neutrino observations and anomalies in the context of sterile neutrinos. Based on a general parametrization motivated in the presence of sterile neutrinos, the consistency of the MINOS disappearance data with additional sterile neutrinos is discussed. We also explore the implications of sterile neutrinos for the measurement of Uμ3|U_{\mu3}| in this case. Regarding the determination of Ue3|U_{e3}|, we observe that the existence of sterile neutrinos may induce a significant modification of the θ13\theta_{13} angle in neutrino appearance experiments like T2K and MINOS, over and above the ambiguities and degeneracies that are already present in 3-neutrino parameter extractions. The modification is less significant in reactor neutrino experiments like Double-CHOOZ, Daya Bay and RENO and therefore the extracted Ue3|U_{e3}| value when sterile neutrinos are present is close to the one that would be obtained in the 3-neutrino case. We also conclude that the results from T2K imply a 90% C.L. lower-bound on Ue3|U_{e3}|, in the "3+2\,3+2" neutrino case, which is still within the sensitivity of future reactor neutrino experiments like Daya Bay, and consistent with the one-σ\sigma range of sin22θ13\sin^22\theta_{13} recently reported by the Double-CHOOZ experiment. Finally, we argue that for the recently determined best-fit parameters, the results in the "3+1\,3+1" scenario would be very close to the medium/long baseline results obtained in the "3+2\,3+2" case analyzed in this work.Comment: 25 pages, 9 figures, revtex4-1. Typos corrected, published versio

    Optimality Theory as a Framework for Lexical Acquisition

    Full text link
    This paper re-investigates a lexical acquisition system initially developed for French.We show that, interestingly, the architecture of the system reproduces and implements the main components of Optimality Theory. However, we formulate the hypothesis that some of its limitations are mainly due to a poor representation of the constraints used. Finally, we show how a better representation of the constraints used would yield better results

    Retinoic acid glucuronide preparations for application to the skin

    Get PDF
    A method and preparation are described for treating human skin with retinoic acid glucuronide (RAG) in a topical carrier. For treatment of acne or wrinkled skin, RAG can be applied in an effective amount which is nonirritating to the skin. Retinoid dermatitis, an objectionable side effect of topical application of retinoid compounds, can thereby be avoided

    Big Data and MapReduce Challenges, Opportunities and Trends

    Get PDF
    Nowadays we all are surrounded by Big data. The term ‘Big Data’ itself indicates huge volume, high velocity, variety and veracity i.e. uncertainty of data which gave rise to new difficulties and challenges. Big data generated may be structured data, Semi Structured data or unstructured data. For existing database and systems lot of difficulties are there to process, analyze, store and manage such a Big Data.  The Big Data challenges are Protection, Curation, Capture, Analysis, Searching, Visualization, Storage, Transfer and sharing. Map Reduce is a framework using which we can write applications to process huge amount of data, in parallel, on large clusters of commodity hardware in a reliable manner. Lot of efforts have been put by different researchers to make it simple, easy, effective and efficient. In our survey paper we emphasized on the working of Map Reduce, challenges, opportunities and recent trends so that researchers can think on further improvement

    Non-teratogenic vitamin A preparation for women of child-bearing age

    Get PDF
    For treatment of acne the glucuronide of retinoic acid (retinoyl β-glucuronide) is orally administered to women of child-bearing age who are capable of conception. This therapy is safer than the oral administration of retinoic acid because retinoic acid glucuronide is essentially non-teratogenic at dose levels effective for the acne treatment. The retinoic acid glucuronide can be in all-trans or 13-cis form

    Simple Pendulum Revisited

    Full text link
    We describe a 8085 microprocessor interface developed to make reliable time period measurements. The time period of each oscillation of a simple pendulum was measured using this interface. The variation of the time period with increasing oscillation was studied for the simple harmonic motion (SHM) and for large angle initial displacements (non-SHM). The results underlines the importance of the precautions which the students are asked to take while performing the pendulum experiment.Comment: 17 pages with 10 figure
    corecore