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Metapopulation approach for landscape level management of western tarnished plant bug,Lygus hesperus,in Texas( Hemiptera,Miridae)

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植物保护学报 2014年第6期41卷 761-768页

作者： Parajulee Megha N shrestha Ram b Texas A & M University System AgriLife Research and Extension Center

Insect source-sink dynamics are vital to ecologically intensive pest management. Maintaining sink plant hosts,or "trap crops",and destroying alternate hosts or breeding places adjacent to the field crop are effective pest management strategies for some arthropods. However,determining whether a host acts as a source or a sink is challenging, especially when the pest species is highly mobile and polyphagous. The western tarnished plant bug,Lygus hesperus,is highly polyphagous,and can utilize >300 hosts. Its presence has been documented in 26 roadside weed hosts in the Texas High *** studies demonstrated that L. hesperus prefer alfalfa over cotton and several alternate weed hosts.A four-year project involved surveying and sampling for L. hesperus in the agricultural landscapes of several sub-regions of the southwestern United States,including the Texas High Plains. In Texas,geographic information of the landscape vegetation complex was compiled from a 150 km radius in the Texas High Plains. In one study,fifty irrigated cotton fields representing the crop diversity within this region were sampled via sweep-net for 10 weeks. This effort also included sampling of up to six noncotton insect habitats within a 3 km radius of each field. Seasonal average L. hesperus abundance data were regressed with 27 field characteristics( variables),including habitat-specific land cover,distance between focal cotton fields and non-cotton habitats,longitude,latitude,elevation,habitat heterogeneity index,and several environmental / ecological variables. Significant variables were selected using a stepwise regression at 15% probability rate. A 10-parameter linear model explained 93% of the variation in the data. Major parameters contributing significantly to variation in L. hesperus abundance in cotton were corn and sunflower acreages,focal cotton field distances from several non-cotton hosts,and habitat heterogeneity index. In addition,field marking-and-capture studies were cond

关键词： western tarnished plant bug cotton IPM ecological pest management alternate host management

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Aging Coefficient, Creep Coefficient and Extrapolating Aging Coefficient from Short Term Test for Sealed Concrete

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Journal of Wuhan University of Technology(Materials Science) 2011年第1期26卷 154-159页

作者： shrestha K M College of Civil Engineering Fuzhou University

Aging coefficient and creep coefficient are important parameters for creep analysis of any structure. With the aim to obtain those parameters, an experimental investigation is carried out on sealed concrete. Altogether ten specimens were tested, out of which four were for creep, two for shrinkage and remaining four for relaxation test. A year of relaxation test and two years of creep test results were analyzed to compute aging coefficient and creep coefficient. From regression analysis of observed and calculated aging coefficient using formula of bazant and Kim, modification for aging coefficient is performed and extrapolation equations are generated. Instead of ACI model, b3 model has been used to obtain compliance function as the parameters of b3 model seems more relevant to creep mechanism of concrete compared to that of ACI model.

关键词： stress strength ratio creep test experimental study b3 model regression analysis

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Effect of debris on seasonal ice melt (2016−2018) on Ponkar Glacier, Manang, Nepal

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Research in Cold and Arid Regions 2020年第5期12卷 261-271页

作者： Reeju shrestha Rijan b.Kayastha Rakesh Kayastha Himalayan Cryosphere Climate and Disaster Research Center(HiCCDRC)Department of Environmental Science and EngineeringSchool of ScienceKathmandu UniversityDhulikhel 45200Nepal

Supraglacial debris is widely present on glaciers in alpine environments and its distribution greatly affects glacier *** present study aims to determine the effect of debris on glacier ice melt on Ponkar Glacier,Manang District,*** estimated ice melt under various debris thickness using Energy balance(Eb)model and conductive heat flux methods,which are compared with in-situ *** stakes are installed on the glacier at different debris thickness of 11−40 *** data from March 2016 to May 2018 are obtained from the Automatic Weather Station(AWS)installed on the glacier surface at an elevation of 3,881 m *** the energy balance *** surface temperature and different debris depths are also measured on the *** calculated ablation rates from the conductive heat flux method are 0.9,1.62 and 0.41 cm/d on pre-monsoon,monsoon and post-monsoon,respectively,with mean debris thermal conductivity 1.04 W/(m∙K).The net radiation shows little variation between the seasons,while turbulent heat flux varies in the *** heat flux was found to be highest in post-monsoon season due to a larger temperature gradient between surface and air.

关键词： debris-covered glacier thermal conductivity energy flux Ponkar Glacier ice melt Hindu-Kush Himalaya

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Liutex core line and POD analysis on hairpin vortex formation in natural flow transition

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Journal of Hydrodynamics 2020年第6期32卷 1109-1121页

作者： Sita Charkrit Pushpa shrestha Chaoqun Liu Department of Mathematics Maejo UniversityChiang MaiThailand Department of Mathematics University of Texas at ArlingtonArlingtonTexas76019USA

In this study,the new method of the vortex core line based on Liutex definition,also known as Liutex core line,is applied to support the hypothesis that the vortex ring is not a part of theΛ-vortex and the formation of the ring-like vortex is formed separately from theΛ-*** proper orthogonal decomposition(POD)is also applied to analyze the Kelvin-VHelmholtz(K-H)instability happening in hairpin ring areas of the flow transition on the flat plate to understand the mechanism of the ring-like vortex *** new vortex identification method named modified Liutex-Omega method is efficiently used to visualize and observe the shapes of vortex structures in *** streamwise vortex structure characteristics can be found in POD mode one as the mean *** other POD modes are in stremwise and spanwise structures and have the fluctuation motions,which are induced by K-H ***,the result shows that POD modes are in pairs and share the same characteristics such as amplitudes,mode shapes,and time *** vortex core and POD results confirm that theΛ-vortex is not self-deformed to a hairpin vortex,but the hairpin vortex is formed by the K-H instability during the development of Lambda vortex to hairpin vortex in the boundary layer flow transition.

关键词： Liutex vector Liutex core line proper orthogonal decomposition(POD)analysis K-H instability Lambda vortex Hairpin vort

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Tree regeneration in gap-understory mosaics in a subtropical Shorea robusta(Sal) forest

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Journal of Forestry Research 2019年第6期30卷 2061-2068页

作者： L.N.Sharma K.b.shrestha I.E.Maren Forest Action Nepal GPO-12207 LalitpurNepal Department of biological Sciences University of BergenThormoensgate 53B5007 BergenNorway

Spatial variation in tree-regeneration density is attributed to the specialization of tree species to light availability for germination and *** availability,in turn,varies across the gap-understorey *** gaps provide an important habitat for the regeneration of tree species that would otherwise be suppressed in the *** subtropical forests,there is still a knowledge-gap relating to how canopy disturbances influence tree-regeneration patterns at local scale,and if they disproportionately favor regeneration of certain *** aim to analyze whether canopy gaps promote tree regeneration,and tree species are specialized to gaps or understory for germination and *** sampled vegetation in 128 plots(0.01 ha),equally distributed in gaps and below canopy,in two subtropical Shorea robusta Gaertn.(Sal)forests in Nepal,recording the number of tree seedlings and saplings in each *** compared the regeneration density of seedlings and saplings separately between gaps and the *** mean densities of seedlings and saplings were higher in the gaps at both sites;although there was no difference in the seedling density of the majority of the species between the *** species were confined to either gap or understorey at the seedling *** conclude that gaps are not critical for the germination of tree species in Sal forests but these are an important habitat for enabling seedlings to survive into *** classification of trees into regeneration guilds mainly based on germination does not apply to the majority of tree species in subtropical Sal *** results reaffirm that gap creation promotes tree regeneration by favouring seedling survival and growth and can influence forest management for conservation,as well as for plantations.

关键词： Canopy-gap Density Regeneration Saplings Seedlings Shade tolerance

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Moving beyond Wastewater:Perspectives on Environmental Surveillance of Infectious Diseases for Public Health Action in Low-Resource Settings

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Environment & Health 2024年第10期2卷 684-687页

作者： Jeseth Delgado Vela Sarah E.Philo Joe brown Mami Taniuchi Molly Cantrell Alexandra Kossik Maya Ramaswamy Sitara SR Ajjampur Fatma Z.Guerfali Rochelle H.Holm John Scott Meschke Maria Catherine b.Otero Amy J.Pickering Mahbubur Rahman Alexander G.Shaw Abhilasha shrestha Kwanrawee Sirikanchana Vivi Maketa Tevuzula Rolf U.Halden Alexandria b.boehm Kyle bibby Department of Civil and Environmental Engineering Duke UniversityDurhamNorth Carolina 27710United States Department of Civil and Environmental Engineering and Earth Sciences University of Notre DameSouth BendIndiana 46556United States Department of Civil and Environmental Engineering University of Southern California Los AngelesCA 90007USA Department of Environmental Sciences and Engineering University of North Carolina at Chapel HillChapel HillNorth Carolina 27599United States Division of Infectious Diseases and International Health University of VirginiaCharlottesvilleVirginia 22903United States Waterborne Disease Prevention branch U.S.Centers for Disease ControlAtlantaGeorgia 30329United States The Wellcome Trust Research Laboratory Christian Medical CollegeVellore 632004India Laboratory of Transmission Control and Immunobiology of Infections(LTCII)Institut Pasteur de TunisTunis-Belvédère 1002Tunisia UniversitéTunis El Manar Tunis 1002Tunisia Christina Lee brown Envirome Institute School of MedicineUniversity of LouisvilleLouisvilleKentucky 40202United States Department of Environmental and Occupational Health Sciences School of Public HealthUniversity of WashingtonSeattleWashington 98195United States College of Medicine University of the Philippines ManilaManila 2801Philippines Department of Civil and Environmental Engineering University of CaliforniaBerkeleyBerkeleyCalifornia 94720United States Institute of Epidemiology Disease Control and Research(IEDCR)Dhaka 1212Bangladesh Department of Infectious Disease Epidemiology Imperial College LondonLondon SW72AZU.K. Division of Environmental and Occupational Health Sciences University of Illinois Chicago School of Public HealthChicagoIllinois 60612United States Research Laboratory of biotechnology Chulabhorn Research InstituteBangkok 10210Thailand Department of Tropical Medicine University of KinshasaKinshasa/DR 63090201Congo School of Sustainable Engineering and the built Environment Arizona State UniversityTempe

Although testing wastewater for public health surveillance has recently received significant attention in the United States,researchers and public health professionals have long realized the tremendous promise of environmental surveillance(ES),defined as tracking pathogens of interest in fecally contaminated surface waters,soil,or fomites,in low-resource settings for public health action.1,2 The power of ES in lowresource settings is most clearly illustrated with the over 30 years of well-established and standardized polio *** part of the Global Polio Eradication Initiative,the World Health Organization(WHO)has accredited 146 laboratories within the Global Polio Lab Network(GPLN).These facilities across 92 countries process over 8,000 wastewater or fecally contaminated surface water samples per year,in addition to over 220,000 stool samples annually.3 The data generated from the GPLN are closely linked to clear public health action related to targeted vaccination *** investment and adoption of ES for polio eradication efforts serves as a use-case for other targets of *** explore the current state of the field,the National Science Foundation-funded Research Coordination Network(RCN)on Wastewater based Epidemiology for SARS-CoV-2 and Emerging Public Health Threats held a workshop in December 2023 to discuss the opportunities and challenges for ES in low-resource settings(Figure 1).Discussions during the workshop highlighted knowledge gaps,best-practices,target selection,academic/government/private partnerships and overall public health action and sustainability of these programs.

关键词： wastewater Wastewater annually

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Distribution Patterns of Medicinal Plants along an Elevational Gradient in Central Himalaya,Nepal

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Journal of Mountain Science 2012年第2期9卷 201-213页

作者： Maan b.ROKAYA Zuzana MÜNZbERGOVÁ Mani R.shrestha binu TIMSINA Institute of botany Academy of Sciences of the Czech Republic Department of botany Faculty of SciencesCharles University School of biological Sciences Monash UniversityClayton Campus Institute for Environmental Studies Faculty of ScienceCharles University

This study aimed to compare the distribution patterns and trends of plant parts used among different groups of medicinal plants, geographical regions,and between medicinal plants and all vascular *** used the published sources for elevation records of 2,331 medicinal plant species to interpolate presence between minimum and maximum elevations and estimated medicinal plant richness for each 100-m elevational band. Monte Carlo simulations were used to test whether differences in elevational distribution between different groups of medicinal plants were significant. Total number of medicinal plants as well as different groups showed unimodal relationship with elevation. The elevational distributions of medicinal plants significantly differ between regions and between medicinal plant *** comparing the richness of all medicinal plants to all vascular plants,Monte Carlo simulations indicated that the numbers of medicinal plants are higher than expected at low *** highest richness of medicinal plants at low elevation could be possibly due to favorable environmental factors such as high temperature, rainfall,sunlight or due to higher density of human population and thus higher pressure on use of any plants in lower elevations.

关键词： Species richness Rapoport's elevational rule Mid-domain effect Randomization test Unimodal pattern Himalaya Nepal

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Habitat Range of two Alpine Medicinal Plants in a Trans-Himalayan Dry Valley,Central Nepal

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Journal of Mountain Science 2009年第1期6卷 66-77页

作者： bharat babu shrestha Pramod Kumar JHA Central Department of botany Tribhuvan UniversityKathmanduNepal

Understanding of the habitat range of threatened Himalayan medicinal plants which are declining in their abundance due to high anthropogenic disturbances is essential for developing conservation strategies and agrotechnologies for cultivation. In this communication, we have discussed the habitat range of two alpine medicinal plants, Aconitum naviculare （bruehl） Stapf and Neopicrorhiza scrophulariiflora （Pennel） Hong in a trans-Himalayan dry valley of central Nepal, Manang district. They are the most prioritized medicinal plants of the study area in terms of ethnomedicinal uses. A. naviculare occurs on warm and dry south facing slopes between 4090-4650 m asl along with sclerophyllous and thorny alpine scrubs, while N. scrophulariiflora is exclusively found on cool and moist north facing slope between 4000 and 4400 m asl where adequate water is available from snow melt to create a suitable habitat for this wetland dependent species. The soil in rooting zone of the two plants differs significantly in organic carbon （OC）, organic matter （OM）, total nitrogen （N） and carbon to nitrogen （C/N） ratio. Due to cool and moist condition of N. scrophulariiflora habitat, accumulation of soil OC is higher, but soil N content is lower probably due to slow release from litter, higher leaching loss and greater retention in perennial live biomass of the plant. The C/N ratio of soil is more suitable in A. navuculare habitat than that of N scrophulariiflora for N supply. Warm and sunny site with N rich soil can be suitable for cultivation ofA. naviculare, while moist and cool site with organic soil for N. scrophulariiflora. The populations of both the plants are fragmented and small. Due to collection by human and trampling damage by livestock, the population of A. naviculare was found absent in open areas in five of the six sampling sites and it was confined only within the bushes of alpine scrubs. For N. serophulariiflora, high probability of complete receding of small glaeiers may be

关键词： Aconitum naviculare Neopicrorhizascrophulariiflora habitat degradation nitrogen organic carbon radiation Manang Nepal

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Assessment of climate change impact on high flows in a watershed characterized by flood regulating reservoirs

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International Journal of Agricultural and biological Engineering 2021年第1期14卷 178-191页

作者： Sabin shrestha Suresh Sharma Civil and Environmental Consultants Inc.BridgeportWV 26554USA Civil/Environmental Engineering Program Youngstown State UniversityOne University PlazaYoungstownOH 44555USA

A climate-induced extreme flow event such as flooding is one of the most devastating natural hazards,which can significantly damage human lives and *** study examined the effects of climate change on the high flow conditions in the Great Miami River Watershed in Ohio under two emission scenarios(RCP 4.5 and RCP 8.5).Streamflow for the 21st century was simulated by utilizing a watershed model-SWAT(Soil and Water Assessment Tool)and 10 different climate outputs from the Coupled Model Intercomparison Project phase 5(CMIP5).The future streamflow was divided into three equal periods:2016-2043(early century),2044-2071(mid-century),and 2072-2099(late century)and independently analyzed to compare high flows of respective intervals with baseline periods(1988-2015).The analysis predicted that 7-day,10-year high-flow(7Q10)would increase by 38%under RCP 4.5 and 44%under RCP ***,the annual peak flows for study periods were predicted to increase by 26%under RCP 4.5 and 38%under RCP 8.5 from the base ***,the analysis demonstrated an erratic response for monthly peaks indicating that the peak flow would increase in summer months-May and July to ***,the result did not show any significant increase during the winter season,especially from November to *** analysis of the four major dams located in the watershed showed that the dam’s peak discharges increase in January,May,and *** though increasing peaks were projected in September for the 21st century,the monthly peaks from the watershed outlet were found to be lowest in September as compared to other *** frequency of future flooding compared to the historical record was found to be increasing in the mid-century under RCP 4.5 and the late century under RCP *** the future flood is projected to increase,this study finds the reasonable impact of climate change on flood regulating reservoirs/dams in monthly ***,daily high flows(90th percentile flow)would b

关键词： climate change high flows SWAT Great Miami River Watershed flood regulating reservoir assessment

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Principal coordinates and principal velocity gradient tensor decomposition

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Journal of Hydrodynamics 2020年第3期32卷 441-453页

作者： Yifei Yu Pushpa shrestha Charles Nottage Chaoqun Liu Department of Mathematics University of Texas at ArlingtonArlington 76019USA

Helmholtz velocity decomposition and Cauchy-Stokes tensor decomposition have been widely accepted as the foundation of fluid kinematics for a long ***,there are some problems with these decompositions which cannot be ***,Cauchy-Stokes decomposition itself is not Galilean invariant which means under different coordinates,the stretching(compression)and deformation are quite *** problem is that the anti-symmetric part of the velocity gradient tensor is not the proper quantity to represent fluid *** show these two drawbacks,two counterexamples are given in this ***“principal coordinate”and“principal decomposition”are introduced to solve the problems of Helmholtz *** easy way is given to find the Principal decomposition which has the property of Galilean invariance.

关键词： Velocity decomposition Helmholtz Cauchy-Stokes Liutex principal coordinate

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