1,046 research outputs found

    Effect of physiological age of stem and IBA treatment on rooting of branch cuttings of Taxus baccata L.

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    The natural population of Taxus baccata L. (Himalayan Yew) throughout the Indian Himalayan Region is greatly reduced due to its extensive and reckless exploitation for “Taxol” an anticancer drug. The effects of overexploitation are exacerbated by the species poor regeneration process, slow growth rate and prolonged seed dormancy. Therefore vegetative propagation by branch cuttings seems to be only practical solution for its large scale multiplication. A study was conducted on six candidate trees (CTs) to examine the effect genotype, physiological age of stem, IBA treatment on rooting of Taxus baccata cuttings. Results revealed that rooting behaviour of cuttings was significantly affected by all the factors under study. Among the six CTs studied, CT 2 (from BSI, Shillong) had given the highest rooting response (46.28%). The juvenile cuttings have the higher rooting capacity; however the callusing was more prominent in mature cutting. The influence of IBA treatment was also significant for rooting where 1000 was most effective for stimulating rooting juvenile cuttings and 2000 ppm in mature cuttings

    Burden of chikungunya in India: estimates of disability adjusted life years (DALY) lost in 2006 epidemic

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    Background & objectives: During 2006, chikungunya emerged as a major ever known epidemic in India. Disability adjusted life years (DALY) is an appropriate summary measure of population health to express epidemiological burden of diseases. We estimated the burden due to suspected chikungunya using DALYs for the first time and compared between the states and also with the burden due to other vector-borne diseases in India. The economic burden was also assessed in terms of productivity loss.Methods: Data on the reported cases of fever/suspected cases of chikungunya from different states during 2006 in India were used. Years lived with disability (YLD) were calculated for non-fatal cases to estimate DALY. Since the disability weight for chikungunya is not available, the weights available for rheumatic arthritis, comparable to the disease outcome of chikungunya were used for the estimation. The burden was estimated for both acute and chronic cases. It is considered that about 11.5% of cases were reported to have extended morbidity with persisting arthralgia. For acute disease, the average duration of illness was considered to be nine days and for chronic cases it was six months on an average. The productivity loss due to income foregone by the working class was calculated using minimum official wage.Results: National burden of chikungunya was estimated to be 25,588 DALYs lost during 2006 epidemic, with an overall burden of 45.26 DALYs per million. It varied from 0.01 to 265.62 per million in different states. Karnataka alone contributed as high as 55% of the national burden. Persistent arthralgia was found to impose heavy burden, accounting for 69% of the total DALYs. The productivity loss in terms of income foregone was estimated to be a minimum of Rs. 391 million. Interpretation & conclusion: The chikungunya epidemic in the year 2006 imposed heavy epidemiological burden and productivity loss to the community. The burden of chikungunya in terms of DALY was estimated for the first time. In view of re-emergence and spread of this infection in recent times it is warranted for derivation of disability weight for different health states of chikungunya to facilitate realistic estimates of DALYs. Quality epidemiological data from surveillance system to monitor vector-borne and zoonotic diseases would pave way for more realistic estimates of burden. The productivity loss in-terms of income foregone could be minimal as the estimation was made by using the minimum wage fixed by the government although the actual loss is expected to be higher

    DIGITIZATION OF EDUCATION AND ITS SOCIO-ECONOMIC IMPACTS WITH SPECIAL REFERENCE TO TRIVANDRUM

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    This study is makes a comparative analysis of the rural-urban divide in digital education and examines the benefits and challenges of e-learning. A total of 124 respondents consisting of students, teachers and parents residing in the rural and urban areas of Trivandrum were surveyed using a well-structured questionnaire administered in both English and Malayalam. The sample population was identified through stratified random sampling. The study finds that disruption of internet connectivity due to signal unavailability is a major challenge of e-learning. Also, majority of the stakeholders were unwilling to make a conscious shift to a digitised education mode. Mostly students favoured online education because of its ease of usage, convenience, remote accessibility and system response speed. But most of the parents and teachers preferred offline education

    Use of Quadrupolar Nuclei for Quantum Information processing by Nuclear Magnetic Resonance: Implementation of a Quantum Algorithm

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    Physical implementation of Quantum Information Processing (QIP) by liquid-state Nuclear Magnetic Resonance (NMR), using weakly coupled spin-1/2 nuclei of a molecule, is well established. Nuclei with spin>>1/2 oriented in liquid crystalline matrices is another possibility. Such systems have multiple qubits per nuclei and large quadrupolar couplings resulting in well separated lines in the spectrum. So far, creation of pseudopure states and logic gates have been demonstrated in such systems using transition selective radio-frequency pulses. In this paper we report two novel developments. First, we implement a quantum algorithm which needs coherent superposition of states. Second, we use evolution under quadrupolar coupling to implement multi qubit gates. We implement Deutsch-Jozsa algorithm on a spin-3/2 (2 qubit) system. The controlled-not operation needed to implement this algorithm has been implemented here by evolution under the quadrupolar Hamiltonian. This method has been implemented for the first time in quadrupolar systems. Since the quadrupolar coupling is several orders of magnitude greater than the coupling in weakly coupled spin-1/2 nuclei, the gate time decreases, increasing the clock speed of the quantum computer.Comment: 16 pages, 3 figure

    Effect of an inhomogeneous external magnetic field on a quantum dot quantum computer

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    We calculate the effect of an inhomogeneous magnetic field, which is invariably present in an experimental environment, on the exchange energy of a double quantum dot artificial molecule, projected to be used as a 2-qubit quantum gate in the proposed quantum dot quantum computer. We use two different theoretical methods to calculate the Hilbert space structure in the presence of the inhomogeneous field: the Heitler-London method which is carried out analytically and the molecular orbital method which is done computationally. Within these approximations we show that the exchange energy J changes slowly when the coupled dots are subject to a magnetic field with a wide range of inhomogeneity, suggesting swap operations can be performed in such an environment as long as quantum error correction is applied to account for the Zeeman term. We also point out the quantum interference nature of this slow variation in exchange.Comment: 12 pages, 4 figures embedded in tex

    Manifestations of Extra Dimensions in a Neutrino Telescope

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    Theories with large extra dimensions provide the possibility that a flavor neutrino, localized in a 3+1 brane, can mix with a singlet neutrino living in the bulk. This mixing leads to unconventional patterns of neutrino matter oscillations and we examine in details how these oscillations depend upon two parameters: the brane-bulk coupling ξ\xi and the effective mass μ\mu of the flavor neutrino inside matter. We find that high energy (E50(E \ge 50 GeV) νμ\nu_\mu neutrinos, to be detected by neutrino telescopes, can give signals of extra dimensions. With a 1 km3m^{3} neutrino telescope extra dimensions with radius down to 1μm1\mu m can be tested directly, while for smaller radius an indirect evidence can be established.Comment: 14 pages, 5 figures, added conclusion

    A Self Assembled Nanoelectronic Quantum Computer Based on the Rashba Effect in Quantum Dots

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    Quantum computers promise vastly enhanced computational power and an uncanny ability to solve classically intractable problems. However, few proposals exist for robust, solid state implementation of such computers where the quantum gates are sufficiently miniaturized to have nanometer-scale dimensions. Here I present a new approach whereby a complete computer with nanoscale gates might be self-assembled using chemical synthesis. Specifically, I demonstrate how to self-assemble the fundamental unit of this quantum computer - a 2-qubit universal quantum controlled-NOT gate - based on two exchange coupled multilayered quantum dots. Then I show how these gates can be wired using thiolated conjugated molecules as electrical connectors. A qubit is encoded in the ground state of a quantum dot spin-split by the Rashba interaction. Arbitrary qubit rotations are effected by bringing the spin splitting energy in a target quantum dot in resonance with a global ac magnetic field by applying a potential pulse of appropriate amplitude and duration to the dot. The controlled dynamics of the 2-qubit controlled-NOT operation (XOR) can be realized by exploiting the exchange coupling with the nearest neighboring dot. A complete prescription for initialization of the computer and data input/output operations is presented.Comment: 22 pages, 4 figure

    The STAR Photon Multiplicity Detector

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    Details concerning the design, fabrication and performance of STAR Photon Multiplicity Detector (PMD) are presented. The PMD will cover the forward region, within the pseudorapidity range 2.3--3.5, behind the forward time projection chamber. It will measure the spatial distribution of photons in order to study collective flow, fluctuation and chiral symmetry restoration.Comment: 15 pages, including 11 figures; to appear in a special NIM volume dedicated to the accelerator and detectors at RHI

    Phi meson production in Au+Au and p+p collisions at sqrt (s)=200 GeV

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    We report the STAR measurement of Phi meson production in Au+Au and p+p collisions at sqrt (s)=200 GeV. Using the event mixing technique, the Phi spectra and yields are obtained at mid-rapidity for five centrality bins in Au+Au collisions and for non-singly-diffractive p+p collisions. It is found that the Phi transverse momentum distributions from Au+Au collisions are better fitted with a single-exponential while the p+p spectrum is better described by a double-exponential distribution. The measured nuclear modification factors indicate that Phi production in central Au+Au collisions is suppressed relative to peripheral collisions when scaled by the number of binary collisions. The systematics of versus centrality and the constant Phi/K- ratio versus beam species, centrality, and collision energy rule out kaon coalescence as the dominant mechanism for Phi production.Comment: 6 pages, 3 figures, submitted to Phys. Rev. Let

    Azimuthal anisotropy and correlations in p+p, d+Au and Au+Au collisions at 200 GeV

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    We present the first measurement of directed flow (v1v_1) at RHIC. v1v_1 is found to be consistent with zero at pseudorapidities η\eta from -1.2 to 1.2, then rises to the level of a couple of percent over the range 2.4<η<42.4 < |\eta| < 4. The latter observation is similar to data from NA49 if the SPS rapidities are shifted by the difference in beam rapidity between RHIC and SPS. Back-to-back jets emitted out-of-plane are found to be suppressed more if compared to those emitted in-plane, which is consistent with {\it jet quenching}. Using the scalar product method, we systematically compared azimuthal correlations from p+p, d+Au and Au+Au collisions. Flow and non-flow from these three different collision systems are discussed.Comment: Quark Matter 2004 proceeding, 4 pages, 3 figure
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