746 research outputs found

    Soil and Plant Analysis - A Strategic Tool to Diagnose Micronutrient Imbalance in Lime and Sapota Orchard in Tablelands of Chambal Ravine Region of India

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    Micronutrient imbalance in lime and sapota fruit crops result in unstable fruit yield, fruit shedding and degrade quality of the produce. A study was therefore conducted to evaluate micronutrient statusoflime and sapota orchard by analysing soil and plant samples. Soil samples were collected from surface (0-15cm) and sub-surface (15-30cm) depth representing whole orchard. At the same time, plant samples including 35-40 each for leaves and petiole samples each from lime and sapota field was also collected. Available micronutrients from soil samples were extracted using diethylenetriaminepenta acetic acid (DTPA) and it was in the order of manganese (Mn)> iron (Fe)> zinc (Zn)> copper (Cu) in both lime and sapota plantations. DTPA- extractable Zn and Cu showed low status, marginal status of Fe and sufficient level of Mn in soils of sapota plantations. In plant analysis, high concentration of Cu (869 mg kg-1) and Zn (411mg kg-1) was observed in lime leaves; however, in sapota crop Cu and Zn content was 8.25mg kg-1 and 16.7mg kg- 1 respectively. Similarly, Fe and Mn content of lime leaves was 197 and 43 mg kg-1 which was slightly higher than sapota leaves that recorded 128 and 49mg kg-1 of Fe and Zn respectively. In sapota plants, higher Mn and Cu concentration in leaf resulted in Zn deficiency symptoms such as shortened internodes or rosette disorders of sapota plants. Thus, correcting micronutrient deficiency is pre-requisite for qualitative and quantitative fruit production in tablelands of India

    Optimization of Regeneration Protocol and Agrobacterium Mediated Transformation in Carnation (Dianthus caryophyllus L.)

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    An efficient and reproducible regeneration protocol for carnation genotypes Arka Flame and IIHRS-1 has been developed from leaf and stem explants. Although IIHRS-1 showed slightly higher regeneration (55%) compared to Arka Flame (49.2%), there was no significant difference in their regeneration response. However, significant difference in regeneration potential was observed with leaf explant exhibiting higher regeneration potential (5.5 shoots/explant) as compared to (4.9) stem explant. Among various plant growth regulator combinations tested for regeneration, the best regeneration response and maximum regeneration potential was obtained in MS medium supplemented with NAA (0.1 mg/l) and TDZ (1.0mg /l) for both the explants and genotypes used. The medium also proved suitable for inducing elongation of regenerated shoots. Rooting of in vitro formed shootlets could be induced at greater frequency in MS medium supplemented with IAA (1.0 mg/l). Based on this protocol, transformation was carried out in genotype IIHRS-1 using leaf explants with Agrobacterium tumefaciens LBA 4404 with binary vector pROK2 containing baculovirus chitinase gene under the control of 35S promoter with npt II serving as selectable marker. There was regeneration of putative transformants at a frequency of 28.9%. However, great difficulty was encountered in rooting of shoots. Hence a few shoots regenerated on selection medium at random were tested for transgene integration. Out of the three shoots tested for npt II amplification, two shoots tested positive. The presence of transgene was confirmed through PCR amplification of npt II gene and dot blot analysis of chitinase gene

    Predicting the response of a submillimeter bolometer to cosmic rays

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    Bolometers designed to detect. submillimeter radiation also respond to cosmic, gamma, and x rays. Because detectors cannot be fully shielded from such energy sources, it is necessary to understand the effect of a photon or cosmic-ray particle being absorbed. The resulting signal (known as a glitch) can then be removed from raw data. We present measurements using an Americium-241 gamma radiation source to irradiate a prototype bolometer for the High Frequency Instrument in the Planck Surveyor satellite. Our measurements showed no variation in response depending on where the radiation was absorbed, demonstrating that the bolometer absorber and thermistor thermalize quickly. The bolometer has previously been fully characterized both electrically and optically. We find that using optically measured time constants underestimates the time taken for the detector to recover from a radiation absorption event. However, a full thermal model for the bolometer, with parameters taken from electrical and optical measurements, provides accurate time constants. Slight deviations from the model were seen at high energies; these can be accounted for by use of an extended model

    Chordoma: The Nonsarcoma Primary Bone Tumor

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/139965/1/onco1344.pd

    Bulk and edge excitations of a ν=1\nu =1 Hall ferromagnet

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    In this article, we shall focus on the collective dynamics of the fermions in a ν=1\nu = 1 quantum Hall droplet. Specifically, we propose to look at the quantum Hall ferromagnet. In this system, the electron spins are ordered in the ground state due to the exchange part of the Coulomb interaction and the Pauli exclusion principle. The low energy excitations are ferromagnetic magnons. In order to obtain an effective Lagrangian for these magnons, we shall introduce bosonic collective coordinates in the Hilbert space of many-fermion systems. These collective coordinates describe a part of the fermionic Hilbert space. Using this technique, we shall interpret the magnons as bosonic collective excitations in the Hilbert space of the many-electron Hall system. Furthermore, by considering a Hall droplet of finite extent, we shall also obtain the effective Lagrangian governing the spin collective excitations at the edge of the sample.Comment: 30 pages, plain TeX, no figure

    Bound States of String Networks and D-branes

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    We show the existence of non-threshold bound states of (p, q) string networks and D3-branes, preserving 1/4 of the full type IIB supersymmetry, interpreted as string networks dissolved in D3-branes. We also write down the expression for the mass density of the system and discuss the extension of the construction to other Dp-branes. Differences in our construction of string networks with the ones interpreted as dyons in N=4 gauge theories are also pointed out.Comment: 11 pages, latex, minor modifications (version to appear in Phys. Rev. Lett.

    Ethylene-mediated nitric oxide depletion pre-adapts plants to hypoxia stress

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    Timely perception of adverse environmental changes is critical for survival. Dynamic changes in gases are important cues for plants to sense environmental perturbations, such as submergence. In Arabidopsis thaliana, changes in oxygen and nitric oxide (NO) control the stability of ERFVII transcription factors. ERFVII proteolysis is regulated by the N-degron pathway and mediates adaptation to flooding-induced hypoxia. However, how plants detect and transduce early submergence signals remains elusive. Here we show that plants can rapidly detect submergence through passive ethylene entrapment and use this signal to pre-adapt to impending hypoxia. Ethylene can enhance ERFVII stability prior to hypoxia by increasing the NO-scavenger PHYTOGLOBIN1. This ethylene-mediated NO depletion and consequent ERFVII accumulation pre-adapts plants to survive subsequent hypoxia. Our results reveal the biological link between three gaseous signals for the regulation of flooding survival and identifies key regulatory targets for early stress perception that could be pivotal for developing flood-tolerant crops

    Stress-driven instability in growing multilayer films

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    We investigate the stress-driven morphological instability of epitaxially growing multilayer films, which are coherent and dislocation-free. We construct a direct elastic analysis, from which we determine the elastic state of the system recursively in terms of that of the old states of the buried layers. In turn, we use the result for the elastic state to derive the morphological evolution equation of surface profile to first order of perturbations, with the solution explicitly expressed by the growth conditions and material parameters of all the deposited layers. We apply these results to two kinds of multilayer structures. One is the alternating tensile/compressive multilayer structure, for which we determine the effective stability properties, including the effect of varying surface mobility in different layers, its interplay with the global misfit of the multilayer film, and the influence of asymmetric structure of compressive and tensile layers on the system stability. The nature of the asymmetry properties found in stability diagrams is in agreement with experimental observations. The other multilayer structure that we study is one composed of stacked strained/spacer layers. We also calculate the kinetic critical thickness for the onset of morphological instability and obtain its reduction and saturation as number of deposited layers increases, which is consistent with recent experimental results. Compared to the single-layer film growth, the behavior of kinetic critical thickness shows deviations for upper strained layers.Comment: 27 pages, 11 figures; Phys. Rev. B, in pres
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