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Production of small molecules by an endophytic fungus,Neofusicoccum parvum from the fruits of Elaeocarpus serratus

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Asian Journal of Traditional Medicines 2020年第2期15卷 47-54页

作者： Dilhara Dissanayake NSavitri Kumar NKBAdikaram lalith jayasinghe Hiroshi Araya Yoshinori Fujimoto National Institute of Fundamental Studies Hantana RoadKandySri Lanka School of Agriculture Meiji UniversityKawasakiKanagawa 214-8571Japan

Neofusicoccum parvum,an endophytic fungus isolated from Elaeocarpus serratus(Ceylon Olive;family Elaeocarpaceae),was grown for 3 weeks in potato dextrose *** separation of the ethyl acetate extracts from the culture filtrate and mycelium over silica gel,Sephadex LH-20 and preparative thin layer chromatography furnished(R)-7-hydroxymellein(1),(3R,4R)-4-hydroxymellein(2),(3R,4S)-4-hydroxymellein(3),(R)-5-hydroxymellein(4),(R)-mellein(5),(3R,4R)-4,7-dihydroxymellein(6),(6R,7S)-dia-asperlin(7),CJ-14445(8)and 13,14,15,16-tetranorlabd-7-ene-19,6β:12,17-diolide(9).The structures of known compounds 1–9 were determined by spectroscopic methods and comparison with reported *** is the first report of the isolation of an endophytic fungus from ***,and the isolation of compounds 1,4,6,8 and 9 from *** is important to note that compounds 1–7 are small molecules with an oxygen heterocyclic ring *** compounds can be used as starting materials in the synthesis of pharmaceutically important large molecules with oxygen heterocyles.

关键词： Neofusicoccum parvum Elaeocarpus serratus endophytic fungi secondary metabolites dihydroisocoumarines

Secondary metabolites from an endophytic fungus Aspergillus fumigatus from Solanum insanum L.

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Asian Journal of Traditional Medicines 2021年第2期16卷 76-82页

作者： Vindya Kanthi Munasinghe N.Savitri Kumar Nimal Adikaram lalith jayasinghe Hiroshi Araya Yoshinori Fujimoto National Institute of Fundamental Studies Hantana RoadKandySri Lanka School of Agriculture Meiji UniversityKawasakiKanagawa214-8571Japan

An endophytic fungus Aspergillus fumigatus,isolated from the fruits of Solanum insanum L.,was cultured in potato dextrose broth *** separation of the EtOAc extract led to the isolation of six secondary metabolites,identified as pseurotin A(1),fumigaclavine C(2),monomethylsulochrin(3),trypacidin(4),fumiquinazoline C(5)and guignasulfide(6)by spectral *** 2 and 3 showed brine shrimp toxicity with IC50 values of 147 and 74.2μM,respectively,while compounds 4 and 5 showed slight inhibition on the growth of fungal pathogen Cladosporium *** is the first report of the isolation of guignasulfide(6)from ***,which has been previously isolated only from an endophytic fungus Guignardia sp.

关键词： Aspergillus fumigatus Endophytic fungi Solanum insanum Guignasulfide

Old-growth mixed dipterocarp forests show variable losses and gains in aboveground biomass and standing carbon over forty years

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Forest Ecosystems 2024年第1期11卷 14-23页

作者： Sisira Ediriweera Champika Bandara Tithira Lakkana Shanika jayasinghe David Woodbury Arun Dayanandan B.M.P.Singhakumara Xiangcheng Mi I.A.U.N.Gunatilleke C.V.S.Gunatilleke Mark SAshton Department of Science and Technology Uva Wellassa UniversityBadullaSri Lanka The Forest School Yale School of the EnvironmentYale UniversityNew HavenCT06511USA Department of Forestry and Environmental Science University of Sri JayewardenepuraNugegodaSri Lanka State Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of SciencesBeijing100093China Botany Department University of PeradeniyaPeradeniyaSri Lanka

Background:No studies have documented long-term trends in aboveground biomass(AGB)for mixed-dipterocarp forests(MDF),the dominant rain forest type in tropical wet equatorial *** our study,we sought to document such trends over forty years across three sites representing lowland to lower montane ***:To do this,we established fifty 100 m×25 m plots in 1978 across three sites sampled along an elevation gradient,identified as mature old-growth *** measured trees for diameter at breast height that we identified to species and *** took wood samples to calculate species wood-specific *** re-measured plots in 1998 and again in ***:We show standing AGB for all sites combined to be 517.52 Mg·ha^(-1)in 1978,but this declined by 17%over 40 years to 430.11 Mg·ha^(-1).No differences exist among sites in AGB primarily because of considerable within site variation;but interactions of time with site show declines across sites were not uniform,one remained about the *** few species represented a high proportion of the AGB with the top five species comprising between 34%and 65%,depending upon site and year *** species,Mesua nagassarium,represented a disproportionately large amount of AGB and decline over time,particularly at the low elevation ***:Our results are directly relevant to estimating AGB and standing carbon sequestered in *** study is the first to demonstrate varying but overall,declining trends in amounts of AGB among forests making predictions of biomass and standing carbon in MDF difficult over wide regions.

关键词： Western ghats Shorea spp. Southeast Asia Sri Lanka Tropical rain forest Wood specific gravity

斯里兰卡初级汉语学习者语音偏误分析及教学对策 ——以凯拉尼亚大学为例

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斯里兰卡初级汉语学习者语音偏误分析及教学对策 ——以凯拉尼亚...

作者： jayasinghe DON UMESHIKA SANU（吴美佳）贵州大学

学位级别：硕士

Dynamic quantitative risk assessment of LNG bunkering SIMOPs based on Bayesian network

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Journal of Ocean Engineering and Science 2023年第5期8卷 508-526页

作者： Hongjun Fan Hossein Enshaei Shantha Gamini jayasinghe Australian Maritime College(AMC) University of TasmaniaLauncestonTas 7248Australia

Liquified natural gas(LNG)bunkering simultaneous operations(SIMOPs)refers to the operations(such as cargo operations,port activities and ship maintenance)occurring around LNG *** pose new risks to LNG bunkering,because the operations are dynamically interlocked in which the occurrence probabilities of potential consequences change at different times due to commencement or completion of specific SIMOP ***,traditional static risk assessment approaches are not able to take the dynamic nature of these new risks into *** article proposes a dynamic quantitative risk as-sessment(DQRA)methodology based on the Bayesian network(BN)to develop better understanding of dynamic risks of LNG bunkering *** methodology is demonstrated and evaluated through a truck-to-ship LNG bunkering case *** results and discussion of the case study validate the utility of the proposed methodology and demonstrate that BNs are efficient in performing the probability calcu-lations and are flexible in conducting causal *** main innovation of this work is realizing the quantification of risks at different times,which reflects the most essential time-changing characteristics of risks associated with LNG bunkering SIMOPs.

关键词： Maritime Alternative fuel Safety LNG bunkering SIMOPs Dynamic risk

Conversion between solid and beam element solutions of finite element method based on meta-modeling theory:development and application to a ramp tunnel structure

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Earthquake Engineering and Engineering Vibration 2017年第2期16卷 297-309页

作者： JASC jayasinghe M. Hori MR Riaz MLL Wijerathne T Ichimura Earthquake Research Institute University of Tokyo Tokyo 113-0032 Japan

In this study, a new method for conversion of solid finite element solution to beam finite element solution is developed based on the meta-modeling theory which constructs a model consistent with continuum mechanics. The proposed method is rigorous and efficient compared to a typical conversion method which merely computes surface integration of solid element nodal stresses to obtain cross-sectional forces. The meta-modeling theory ensures the rigorousness of proposed method by defining a proper distance between beam element and solid element solutions in a function space of continuum mechanics. Results of numerical verification test that is conducted with a simple cantilever beam are used to find the proper distance function for this conversion. Time history analysis of the main tunnel structure of a real ramp tunnel is considered as a numerical example for the proposed conversion method. It is shown that cross-sectional forces are readily computed for solid element solution of the main tunnel structure when it is converted to a beam element solution using the proposed method. Further, envelopes of resultant forces which are of primary importance for the purpose of design, are developed for a given ground motion at the end.

关键词： meta-modeling theory finite element method solid and beam element models continuum mechanics structural mechanics

Influence of biochar on growth performances,yield of root and tuber crops and controlling plant-parasitic nematodes

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Biochar 2023年第1期5卷 1174-1188页

作者： Randima Edussuriya Anushka Upamali Rajapaksha Chamila jayasinghe Chaamila Pathirana Meththika Vithanage Ecosphere Resilience Research Center Faculty of Applied SciencesUniversity of Sri JayewardenepuraNugegoda 10250Sri Lanka Instrument Center Faculty of Applied SciencesUniversity of Sri JayewardenepuraNugegoda 10250Sri Lanka Department of Food Science and Technology Faculty of LivestockFisheries and NutritionWayamba University of Sri LankaMakanduraGonawila 60170Sri Lanka Department of Forestry and Environmental Science Faculty of Applied SciencesUniversity of Sri JayewardenepuraNugegoda 10250Sri Lanka Sustainability Cluster School of EngineeringUniversity of Petroleum&Energy StudiesDehradunUttarakhand 248007India Institute of Agriculture University of Western AustraliaPerthWA 6009Australia

Root and tuber crops are important sources of food and provide income for millions of people worldwide besides an observed high demand for organically produced ***,recent attention has been given to utilizing biochar,a carbon-rich material produced from the pyrolysis of organic materials,which improves soil structure,water-holding capacity,and nutrient availability,as an amendment to produce organic root and tuber *** effects are caused by the formation of organic coatings on the surface of biochar,which decreases hydrophobicity and increases the ability to retain nutrients,acting as a slow-release mechanism delivering nutrients dependent on plant physiological ***,comprehensive studies on the impact of biochar application on root and tuber crop growth,productivity,and effectiveness in eliminating soil parasites have not been extensively ***,the purpose of this review is to explore the use of biochar and biochar-based soil amendments and their potential applications for improving the growth,yield,and efficacy of controlling parasitic nematodes in a wide range of root *** of the studies have investigated the effects of biochar on cassava,sweet potatoes,and minor root crops such as ginger and *** has been observed that biochar application rates(5-20 t ha^(−1))increase the vine length and the number of leaves,tubers,and tuber *** addition of biochar demonstrates the ability to control plant-parasitic nematodes in a rate-dependent *** biochar has shown promising results in improving crop growth and yield of limited root and tuber crops based on a few biochar types,ample opportunities are around to evaluate the influence of biochar produced in different temperatures,feedstock,modifications and controlling parasitic nematodes.

关键词： Crop yield Carbon materials Organic fertilizer Root and tuber crops Nutrient retention Nematodes

Application for developing countries:Estimating trip attraction in urban zones based on centrality

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Journal of Traffic and Transportation Engineering(English Edition) 2017年第5期4卷 464-476页

作者： Amila jayasinghe Kazushi Sano Kasemsri Rattanaporn Department of Civil and Environmental Engineering Nagaoka University of TechnologyNagaoka 940-2137Japan

This paper introduced a network centrality-based method to estimate the volume of trip attraction in traffic analysis zones. Usually trip attraction volumes are estimated based on land use characteristics. However, executing of land use-based trip attraction models are severely constrained by the lack of updated land use data in developing countries. The proposed method used network centrality-based explanatory variables as ＂connectivity＂, ＂local integration＂ and ＂global integration＂. Space syntax tools were used to compute the centrality of road segments. GIS-based kernel density estimation method was used to transform computed road segrnent-based centrality values into traffic analysis zone. Trip attraction values exhibited significant high correlation with connectivity, global and local integration values. The study developed and validated model to estimate trip attraction by using connectivity, local integration and global integration values as endogenous variables with an accepted level of accuracy （R2 〉 0.75）. The proposed approach required minimal data, and it was easily executed using a geographic information system. The study rec- ommended the proposed method as a practical tool for transport planners and engineers, especially who work in developing countries and where updated land use data is unavailable.

关键词： Trip attraction Centrality Space syntax Land use Developing country

Attenuation of rock blasting induced ground vibration in rock-soil interface

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Journal of Rock Mechanics and Geotechnical Engineering 2019年第4期11卷 770-778页

作者： Bhagya jayasinghe Zhiye Zhao Anthony Goh Teck Chee Hongyuan Zhou Yilin Gui School of Civil and Environmental Engineering Nanyang Technological UniversitySingapore Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing University of TechnologyBeijingChina School of Civil Engineering and Geosciences Newcastle UniversityNewcastle upon TyneUK

Blasting has been widely used in mining and construction industries for rock *** paper presents the results of a series of field tests conducted to investigate the ground wave propagation through mixed geological *** tests were conducted at a site in the northwestern part of Singapore composed of residual soil and granitic *** field test aims to provide measurement data to better understand the stress wave propagation in soil/rock and along their *** accelerometers were used for the free field vibration *** measured results are presented and discussed,and empirical formulae for predicting peak particle velocity (PPV) attenuation along the ground surface and in soil/rock were derived from the measured ***,the ground vibration attenuation across the soil-rock interface was carefully examined,and it was found that the PPV of ground vibration was decreased by 37.2% when it travels from rock to soil in the vertical direction.

关键词： Rock blasting Field tests Blast wave propagation Peak particle velocity (PPV) Rock-soil interface