249 research outputs found

    Identifying Medicinal Plant Leaves Using Textures and Optimal Colour Spaces Channel

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    This paper presents an automated medicinal plant leaf identification system. The Colour Texture analysis of the leaves is done using the statistical, the Grey Tone Spatial Dependency Matrix(GTSDM) and the Local Binary Pattern(LBP) based features with 20 different colour spaces(RGB, XYZ, CMY, YIQ, YUV, YCbCrYC_{b}C_{r}, YES, UVWU^{*}V^{*}W^{*}, LabL^{*}a^{*}b^{*}, LuvL^{*}u^{*}v^{*}, lms, lαβl\alpha\beta, I1I2I3I_{1} I_{2} I_{3}, HSV, HSI, IHLS, IHS, TSL, LSLM and KLT). Classification of the medicinal plant is carried out with 70\% of the dataset in training set and 30\% in the test set. The classification performance is analysed with Stochastic Gradient Descent(SGD), kNearest Neighbour(kNN), Support Vector Machines based on Radial basis function kernel(SVM-RBF), Linear Discriminant Analysis(LDA) and Quadratic Discriminant Analysis(QDA) classifiers. Results of classification on a dataset of 250 leaf images belonging to five different species of plants show the identification rate of 98.7 \%. The results certainly show better identification due to the use of YUV, LabL^{*}a^{*}b^{*} and HSV colour spaces

    High-temperature weak ferromagnetism on the verge of a metallic state: Impact of dilute Sr-doping on BaIrO3

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    The 5d-electron based BaIrO3 is a nonmetallic weak ferromagnet with a Curie temperature at Tc=175 K. Its largely extended orbitals generate strong electron-lattice coupling, and magnetism and electronic structure are thus critically linked to the lattice degree of freedom. Here we report results of our transport and magnetic study on slightly Sr doped BaIrO3. It is found that dilute Sr-doping drastically suppresses Tc, and instantaneously leads to a nonmetal-metal transition at high temperatures. All results highlight the instability of the ground state and the subtle relation between magnetic ordering and electron mobility. It is clear that BaIrO3 along with very few other systems represents a class of materials where the magnetic and transport properties can effectively be tuned by slight alterations in lattice parameters

    Pest management in grain legumes and climate change

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    Grain legumes such as chickpea, pigeonpea, cowpea, field pea, lentil, faba bean, black gram, green gram, grasspea, and Phaseolus beans play an important role in food and nutritional security, and sustainable crop production. Several insect pests damage these crops, of which pod borer, Helicoverpa armigera; spotted pod borer, Maruca vitrata; spiny pod borer, Etiella zinckenella; pod fly, Melanagromyza obtusa; stem fly, Ophiomyia phaseoli; pea and bean weevil, Sitona spp.; aphids, Aphis craccivora and Aphis fabae; white fly, Bemisia tabaci; defoliators, Spodoptera litura, S. exigua, and Amsacta spp.; leafhoppers, Empoasca spp., thrips, Megaleurothrips dorsalis, and Caliothrips indicus; blister beetles, Mylabris spp.; and the bruchids, Callasobruchus chinensis and Bruchus pisorum cause extensive losses. The incidence and extent of losses due to these pests varies across seasons, locations, and cropping systems. This scenario will change considerably due to impending global warming and climate change. The geographical distribution of some of the pests will extend to northern Europe and America, while the outbreks of some other pests will become more frequent. Several sources of resistance to insects have been identified in grain legumes, and improved cultivars also been developed in some crops. However, there are limitations to large-scale adoption of insect-resistant cultivars because of limited efforts in seed production and seed distribution. Cultural manipulation of the crop and its environment involving intercropping, population monitoring, manipulation of cropping systems to encourage the activity of natural enemies, use of natural plant products and bio-pesticides alone or in combination with synthetic pesticides, deployment of insect-resistant varieties derived through conventional breeding or genetic engineering, and need based application of synthetic pesticides can be used for pest management in grain legumes for sustainable crop production. The relative efficacy of some of these pest management tactics, particularly biopesticides and natural plant product might reduce considerably in warm climates. In addition, there will be greater genotype × environment interaction for expression of resistance to insect pests, and this warrants a greater effort for identification of diverse sources of resistance to insects, and develop integrated pest management packages that will be effective under variable climatic condition

    A mitochondrial membrane-bridging machinery mediates signal transduction of intramitochondrial oxidation

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    Mitochondria are the main site for generating reactive oxygen species, which are key players in diverse biological processes. However, the molecular pathways of redox signal transduction from the matrix to the cytosol are poorly defined. Here we report an inside-out redox signal of mitochondria. Cysteine oxidation of MIC60, an inner mitochondrial membrane protein, triggers the formation of disulfide bonds and the physical association of MIC60 with Miro, an outer mitochondrial membrane protein. The oxidative structural change of this membrane-crossing complex ultimately elicits cellular responses that delay mitophagy, impair cellular respiration and cause oxidative stress. Blocking the MIC60–Miro interaction or reducing either protein, genetically or pharmacologically, extends lifespan and health-span of healthy fruit flies, and benefits multiple models of Parkinson’s disease and Friedreich’s ataxia. Our discovery provides a molecular basis for common treatment strategies against oxidative stress

    Borderline magnetism in Sr4Ru3O10: Impact of dilute La and Ca doping on itinerant ferromagnetism and metamagnetism

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    An investigation of La and Ca doped Sr4Ru3O10, featuring a coexistence of interlayer ferromagnetism and intralayer metamagnetism, is presented. La doping readily changes magnetism between ferromagnetism and metamagnetism by tuning the density of states. It also results in different Curie temperatures for the c-axis and the basal plane, highlighting a rare spin-orbit coupling with the crystal field states. In contrast, Ca doping enhances the c-axis ferromagnetism and the magnetic anisotropy. La doping also induces a dimensional crossover in the interlayer transport whereas Ca doping exhibits a tunneling magnetoresistance and an extraordinary T3/2-dependence of the resisitivity. The drastic changes caused by the dilute doping demonstrate a rare borderline magnetism that is delicately linked to the interplay of the density of states and spin-orbit coupling.Comment: 5 figure

    Novel Jeff = 1/2 Mott State Induced by Relativistic Spin-Orbit Coupling in Sr2IrO4

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    We investigated electronic structure of 5d transition-metal oxide Sr2IrO4 using angle-resolved photoemission, optical conductivity, and x-ray absorption measurements and first-principles band calculations. The system was found to be well described by novel effective total angular momentum Jeff states, in which relativistic spin-orbit (SO) coupling is fully taken into account under a large crystal field. Despite of delocalized Ir 5d states, the Jeff-states form so narrow bands that even a small correlation energy leads to the Jeff = 1/2 Mott ground state with unique electronic and magnetic behaviors, suggesting a new class of the Jeff quantum spin driven correlated-electron phenomena.Comment: 12 pages, 4 figure

    ADAM17-dependent proteolysis of L-selectin promotes early clonal expansion of cytotoxic T cells

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    L-selectin on T-cells is best known as an adhesion molecule that supports recruitment of blood-borne naïve and central memory cells into lymph nodes. Proteolytic shedding of the ectodomain is thought to redirect activated T-cells from lymph nodes to sites of infection. However, we have shown that activated T-cells re-express L-selectin before lymph node egress and use L-selectin to locate to virus-infected tissues. Therefore, we considered other roles for L-selectin proteolysis during T cell activation. In this study, we used T cells expressing cleavable or non-cleavable L-selectin and determined the impact of L-selectin proteolysis on T cell activation in virus-infected mice. We confirm an essential and non-redundant role for ADAM17 in TCR-induced proteolysis of L-selectin in mouse and human T cells and show that L-selectin cleavage does not regulate T cell activation measured by CD69 or TCR internalisation. Following virus infection of mice, L-selectin proteolysis promoted early clonal expansion of cytotoxic T cells resulting in an 8-fold increase over T cells unable to cleave L-selectin. T cells unable to cleave L-selectin showed delayed proliferation in vitro which correlated with lower CD25 expression. Based on these results, we propose that ADAM17-dependent proteolysis of L-selectin should be considered a regulator of T-cell activation at sites of immune activity
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