28 research outputs found

    Optimal Control Applied to a Visceral Leishmaniasis Model

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    In this article, we developed a deterministic model for the transmission dynamics of visceral leishmaniasis in humans, canine reservoirs and sandflies, which is the only vector that transmits the disease parasite. The theoretical and epidemiological findings of this study indicates that the diseasefree equilibrium of the model is locally and globally asymptotically stable when the associated reproduction number is less than unity. We perform sensitivity analysis on the model parameter to determine the parameter with the most impact on the reproduction number. Following the results obtained from the sensitivity analysis, we apply optimal control theory using three time dependent control variables representing personal protection, insecticide spraying and culling of infected canine reservoirs. Simulation results are presented for various outbreak scenarios which indicates that leishmaniasis can be eliminated from a region by the application of three time dependent controls representing respectively, personal protection, insecticide spraying and culling infected canine reservoir

    Selection of Pyramided Barley Advanced Lines for Stripe Rust, Leaf Rust and Crown Rust Diseases Using Molecular Markers

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    Barley diseases are the major yield limiting factors for barley cultivation in Nepal. Stripe/Yellow rust (P. striformis f.sp. hordei and P. striformis f.sp. tritici), leaf rust (Puccinia hordei), and crown rust (P. coronata) are the major rust diseases in Nepal. Pyramiding resistance genes against all these rust diseases are possible through molecular marker assisted breeding. Sweden originated barley variety ‘Bonus’ is found resistant to stripe rust and having linked microsatellite markers for stripe rust and crown rust resistance. Similarly, Nepalese hull-less barley variety ‘Solu Uwa’ and Nepalese awn-less barley landrace NPGR Acc# 2478 have linked microsatellite markers for leaf rust resistance. Therefore, one polymorphic sequence tagged sites (STS) marker (ABG054) for stripe rust resistance, two polymorphic simple sequence repeats (SSR) markers (Bmac0144h and HVM049) for leaf rust and one polymorphic SSR marker (Bmag0006) for crown rust resistance were used to select the advanced barley lines (at F8 stage) from above parents. Field screening of stripe rust resistance was also conducted. Among 51 advanced and field disease resistance lines from Bonus/Solu Uwa cross, we have selected 10 pyramided lines for all three types of barley rust resistance. Similarly, among 39 advanced and field disease resistance lines from Bonus/NPGR Acc#2478 cross we have selected three pyramided lines and advanced for further yield testing for general cultivation purpose. The chances of losing the desired gene are high in late generation selection using molecular marker assisted selection (MAS); but the chances of getting agronomically superior varietal output will also increase

    Next Generation Radiation Hard IMM Space Solar Cells

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    High efficiency space solar cells based on the GaInP2/InGaAs/Ge triple junction lattice matched device with 1 sun, AM0 efficiencies of approximately 30% are commercially available from several companies. Multiple approaches have been suggested for significantly surpassing the 30% efficiency level, but achieving this in a commercially viable cell has not been easy. We review those approaches, pointing out the advantages and challenges of each. SolAero has been focused on developing the inverted metamorphic multi-junction (IMM) solar cell, and has recently demonstrated a radiation hard version. We present the most recent performance data, including the response to particle radiation. The IMM cell can be used in a number of rigid or flexible configurations, and considerable effort has been focused on cell packaging and panel integration. The IMM device is ready to start qualification to the ECSS and AIAA standards

    Application of frequency ratio, statistical index, and weights-of-evidence models and their comparison in landslide susceptibility mapping in Central Nepal Himalaya

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    The Mugling–Narayanghat road section falls within the Lesser Himalaya and Siwalik zones of Central Nepal Himalaya and is highly deformed by the presence of numerous faults and folds. Over the years, this road section and its surrounding area have experienced repeated landslide activities. For that reason, landslide susceptibility zonation is essential for roadside slope disaster management and for planning further development activities. The main goal of this study was to investigate the application of the frequency ratio (FR), statistical index (SI), and weights-of-evidence (WoE) approaches for landslide susceptibility mapping of this road section and its surrounding area. For this purpose, the input layers of the landslide conditioning factors were prepared in the first stage. A landslide inventory map was prepared using earlier reports, aerial photographs interpretation, and multiple field surveys. A total of 438 landslide locations were detected. Out these, 295 (67 %) landslides were randomly selected as training data for the modeling using FR, SI, and WoE models and the remaining 143 (33 %) were used for the validation purposes. The landslide conditioning factors considered for the study area are slope gradient, slope aspect, plan curvature, altitude, stream power index, topographic wetness index, lithology, land use, distance from faults, distance from rivers, and distance from highway. The results were validated using area under the curve (AUC) analysis. From the analysis, it is seen that the FR model with a success rate of 76.8 % and predictive accuracy of 75.4 % performs better than WoE (success rate, 75.6 %; predictive accuracy, 74.9 %) and SI (success rate, 75.5 %; predictive accuracy, 74.6 %) models. Overall, all the models showed almost similar results. The resultant susceptibility maps can be useful for general land use planning

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    Parallel Sessions: Session 4

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    First-Principles Study of Adsorption of Halogen Molecules on Graphene-MoS2 Bilayer Hetero-system

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    We have performed density functional theory based first-principles calculations to study the stability, geometrical structures and electronic properties of pure 3x3 supercell of MoS2, 4x4 supercell of graphene, graphene-MoS2 bilayer hetero-system, F-2, Cl-2, Br-2 and I-2 molecules on hetero-system within the DFT-D-2 level of approximations. The preferable site and adsorption energy of halogen molecules are studied. The most stable geometries are considered to study their electronic band structure, Density of states and magnetic properties with reference to individual 2D components, graphene and MoS2
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