239 research outputs found

    On the existence and multiplicity of positive solutions to classes of steady state reaction diffusion systems with multiple parameters

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    We study positive solutions to the steady state reaction diffusion systems of the form: \begin{equation} \left\{\begin{array}{ll} -\Delta u = \lambda f(v)+\mu h(u), & \Omega,\\ -\Delta v = \lambda g(u)+\mu q(v),& \Omega,\\ \frac{\partial u}{\partial \eta}+\sqrt[]{\lambda +\mu}\, u=0,& \partial\Omega,\\ \frac{\partial v}{\partial \eta}+\sqrt[]{\lambda +\mu}\, v=0, & \partial\Omega,\\ \end{array}\right. \end{equation} where λ,μ>0{\lambda,\mu>0} are positive parameters, Ω{\Omega} is a bounded in RN\mathbb{R}^{N}(N>1)(N>1) with smooth boundary Ω{\partial \Omega}, or Ω=(0,1){\Omega=(0,1)}, zη{ \frac{\partial z}{\partial \eta} } is the outward normal derivative of zz. Here f,g,h,qC2[0,r)C[0,)f, g, h, q\in C^{2} [0,r)\cap C[0,\infty) for some r>0r>0. Further, we assume that f,g,hf, g, h and qq are increasing functions such that f(0)=g(0)=h(0)=q(0)=0f(0) = g(0) = h(0) = {q}(0) = 0, f(0),g(0),h(0),q(0)>0f^\prime(0), g^\prime(0), h^\prime(0), q^\prime(0) > 0, and limsf(Mg(s))s=0\lim\limits_{s\to \infty}\frac{f(M g(s))}{s}=0 for all M>0M>0. Under certain additional assumptions on f,g,hf, g, h and q q we prove our existence and multiplicity results. Our existence and multiplicity results are proved using sub-super solution methods

    Incidence of some pathogenic organisms in cultured shrimp (penaeus monodon) collected from Chilaw

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    Samples offarm shrimp and pond water were collectedfrom Chi/aw. Totalbacterial counts of coliforms and Escherichia coli are reportedfor these samples.Pathogens Vibrio parahaemolyticus, and Salmonella along with qualitativemicroflora are also reported.The bacterial counts of water rangedfrom 5 x 102/gto 8.8 x 103/g whereasthat of shrimp rangedfrom 2.0 x IO"/g to 9.0 x lO'/g. E. coli. ranged from 3 toII/g for prawns 3/I00ml. to 49/I00ml. for pond water. Two shrimp sampleswere positive for v. parahaemolyticus bacterial counts, coliforms or E. colicounts did not show any correlation with water salinity, which rangedfrom 14-18ppt,Gram positive bacteria were predominant in shrimp and were representedby Micrococci (41.8%). Corynebacterium (19.3%) and Bacillus (14.2%).Common gram-negatives were Vibrios (19.2%) and Pseudomonas (5%)

    Defining inflammatory cell states in rheumatoid arthritis joint synovial tissues by integrating single-cell transcriptomics and mass cytometry

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    © 2019, The Author(s), under exclusive licence to Springer Nature America, Inc. To define the cell populations that drive joint inflammation in rheumatoid arthritis (RA), we applied single-cell RNA sequencing (scRNA-seq), mass cytometry, bulk RNA sequencing (RNA-seq) and flow cytometry to T cells, B cells, monocytes, and fibroblasts from 51 samples of synovial tissue from patients with RA or osteoarthritis (OA). Utilizing an integrated strategy based on canonical correlation analysis of 5,265 scRNA-seq profiles, we identified 18 unique cell populations. Combining mass cytometry and transcriptomics revealed cell states expanded in RA synovia: THY1(CD90) + HLA-DRA hi sublining fibroblasts, IL1B + pro-inflammatory monocytes, ITGAX + TBX21 + autoimmune-associated B cells and PDCD1 + peripheral helper T (T PH ) cells and follicular helper T (T FH ) cells. We defined distinct subsets of CD8 + T cells characterized by GZMK + , GZMB + , and GNLY + phenotypes. We mapped inflammatory mediators to their source cell populations; for example, we attributed IL6 expression to THY1 + HLA-DRA hi fibroblasts and IL1B production to pro-inflammatory monocytes. These populations are potentially key mediators of RA pathogenesis

    Salivary Interleukin Levels in Oral Squamous Cell Carcinoma and Oral Epithelial Dysplasia : Findings from a Sri Lankan Study

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    Acknowledgments The authors would like to thank the laboratory staff at the Department of Microbiology, Faculty of Medical Sciences, University of Sri Jayewardenepura, Gangodawila, Nugegoda, Sri Lanka. The authors would like to thank Thilini Nisansala and Chamikara Liyanage for their help in the laboratory analysis. Funding N.S.P. was financially supported by the Elphinstone Scholarship, University of Aberdeen, UK and the University Grants Commission, Sri Lanka.Peer reviewedPublisher PD

    Improving seed germination of the eggplant rootstock Solanum torvum by testing multiple factors using an orthogonal array design

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    [EN] Solanum torvum is a highly vigorous relative of eggplant that is resistant to a number of harmful soil-borne diseases and is compatible for grafting with eggplant. Being a potential rootstock, this plant frequently presents poor and erratic germination, which makes its practical use difficult. We used an L8 (2(7)) orthogonal array design to evaluate the primary effects of seven factors (soaking of seeds, scarification with sodium hypochlorite (NaClO), application of gibberellic acid (GA(3)), use of potassium mitrate (KNO3) as a moistening agent, cold stratification, application of a heatshock, and light irradiation during germination) at two levels (L0 and L1) using four germination parameters (early and final germination, germination rate and vigour index) in fresh S. torvum seeds. S. torvum seeds had a strong dormancy with no germination in the untreated seeds and high early and final germination (approximately 100%) in certain treatments. An evaluation of the main effects revealed highly positive effects on germination from seed soaking, and the use of GA(3), KNO3, and light irradiation, whereas NaClO scarification had a negative effect. The application of cold stratification and heat shock treatments also had a positive effect on seed germination but to a lesser extent than the other treatments. An improved proposed protocol that consisted of subjecting seeds to soaking, the application of GA(3) and KNO3, cold stratification, heat shock, and light irradiation was validated and demonstrated to be highly effective, with seed germination success greater than 60% being observed at 3 days and final germination reaching a plateau at 6 days. A second validation experiment using a commercial growing substrate also showed a high emergence (approximately 50%) at 7 days and a final germination of approximately 80% was recorded with application of the improved protocol. The seed germination protocol that we have developed will facilitate the use of S. torvum as a rootstock for eggplant and its use in breeding programmes. Our results also reveal that orthogonal array designs are a powerful tool for establishing improved protocols for seed germination. (C) 2015 Elsevier B.V. All rights reserved.This work was completed as part of the initiative "Adapting Agriculture to Climate Change: Collecting, Protecting and Preparing Crop Wild Relatives", which is supported by the Government of Norway. The project is managed by the Global Crop Diversity Trust with the Millennium Seed Bank of the Royal Botanic Gardens, Kew and is implemented in partnership with national and international gene banks and plant breeding institutes. For further information see the project website: http://www.cwrdiversity.org/. Isabel Andujar and Pietro Gramazio are grateful to Universitat Politecnica de Valencia for their post-doctoral (PAID-10-14) and pre-doctoral (Programa FPI de la UPV-Subprograma 1) contracts, respectively.Ranil, RH.; Niran, HML.; Plazas Ávila, MDLO.; Fonseka, R.; Hemal Fonseka, H.; Vilanova Navarro, S.; Andújar Pérez, I.... (2015). Improving seed germination of the eggplant rootstock Solanum torvum by testing multiple factors using an orthogonal array design. Scientia Horticulturae. 193:174-181. https://doi.org/10.1016/j.scienta.2015.07.030S17418119

    Robust Protection of III-V Nanowires in Water Splitting by a Thin Compact TiO2 Layer.

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    Narrow-band-gap III-V semiconductor nanowires (NWs) with a suitable band structure and strong light-trapping ability are ideal for high-efficiency low-cost solar water-splitting systems. However, due to their nanoscale dimension, they suffer more severe corrosion by the electrolyte solution than the thin-film counterparts. Thus, short-term durability is the major obstacle for using these NWs for practical water-splitting applications. Here, we demonstrated for the first time that a thin layer (∼7 nm thick) of compact TiO2 deposited by atomic layer deposition can provide robust protection to III-V NWs. The protected GaAs NWs maintain 91.4% of its photoluminescence intensity after 14 months of storage in ambient atmosphere, which suggests the TiO2 layer is pinhole-free. Working as a photocathode for water splitting, they exhibited a 45% larger photocurrent density compared with unprotected counterparts and a high Faraday efficiency of 91% and can also maintain a record-long highly stable performance among narrow-band-gap III-V NW photoelectrodes; after 67 h photoelectrochemical stability test reaction in a strong acid electrolyte solution (pH = 1), they show no apparent indication of corrosion, which is in stark contrast to the unprotected NWs that fully failed after 35 h. These findings provide an effective way to enhance both stability and performance of III-V NW-based photoelectrodes, which are highly important for practical applications in solar-energy-based water-splitting systems

    Evaluation of pigeonpea accessions and selected lines for reaction to Maruca

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    Maruca vitrata (Geyer) is a serious insect pest of tropical legumes. In Sri Lanka, yield losses due to Maruca damage in pigeonpea [Cajanus cajan (L.) Millsp.] range up to 100%. The development of resistant cultivars and germplasm is one of the best means of control. The objectives of this study were to screen 271 accessions for resistance to M. vitrata and evaluate reaction of lines selected from the promising accessions. The high level of natural incidence of Maruca in Sri Lanka provided an opportunity for evaluation of germplasm at Field Crops Research and Development Institute, Maha Illuppallama. Screening of the germplasm accessions revealed large variation in Maruca damage to flowers and pods. On average, the Maruca damage in determinate accessions (66–75%) was higher than that of nondeterminate accessions (41–50%). Resistant plants from four determinate and 12 nondeterminate accessions were selected. Further selection for resistance to Maruca damage among and within lines derived from the resistant plants was exercised for six generations under nonsprayed field conditions. Under insecticide-free conditions, the selections from two accessions showed significant yield advantages over controls. Data on pod damage and larval counts indicated that the resistance was conditioned through yield compensation mechanisms. In pigeonpea, this is the first report of the selection of Maruca resistant lines. Further studies showed that by using the resistant genotypes it is possible to reduce the number of insecticide sprays for economic yields

    Frequency of natural out-crossing in partially cleistogamous pigeonpea lines in diverse environments

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    Natural out-crossing is the major cause of loss of varietal purity in pegeonpea [Cajanus cajan (L.) Millsp.]. The frequency of natural out-crossing of partially cleistogamous mutant lines, characterized by a modified keel and filamentous anthers, was studied at two locations in Sri Lanka and three locations in India. Indeterminate growth habit and normal floral morphology were used as dominant markers and the frequency of anural out-crossing was estimated as percentage of the observed hybrid plants. Natural out-crossing in the mutant lines in Sri Lanka ranged from 0.14 to 1.33% in comparison to 6.34 to 19.64% in the controls. In the Indian environments, natural outcrossing ranged from 0.16 to 2.67%. The mutant was higly stable over diverse environments, and may be of considerable economic importance in pigeonpea improvement and seed-production programs
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