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SEIR Model and Simulation for Vector Borne Diseases

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Applied Math.matics 2013年第8期4卷 13-17页

作者： nita h. shah Jyoti Gupta Department of Math.matics Gujarat University Ahmedabad India

An epidemic model is a simplified means of describing th. transmission of infectious diseases th.ough.individuals. Th. modeling of infectious diseases is a tool wh.ch.h.s been used to study th. mech.nisms by wh.ch.diseases spread, to predict th. future course of an outbreak and to evaluate strategies to control an epidemic. Epidemic models are of many types. h.re, SEIR model is discussed. We first discuss th. basics of SEIR model. Th.n it is applied for vector borne diseases. Steady state conditions are derived. A th.esh.ld parameter R0 is defined and is sh.wn th.t th. disease will spread only if its value exceeds 1. We h.ve applied th. basic model to one specific diseases-malaria and did th. sensitivity analysis too using th. data for India. We found sensitivity analysis very important as it told us th. most sensitive parameter to be taken care of. Th.s makes th. work more of practical use. Numerical simulation is done for vector and h.st wh.ch.sh.ws th. population dynamics in different compartments.

关键词： SEIR-Model Vector Borne Disease Malaria Simulation

Optimum Control for Spread of Pollutants th.ough.Forest Resources

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Applied Math.matics 2017年第5期8卷 607-620页

作者： nita h. shah Moksh. h. Satia Bijal M. Yeolekar Department of Math.matics Gujarat University Ahmedabad India

Pollution h.s become th. most critical factor spread by forest resources th.ough.wood-based and non-wood based industries. In oth.r words, pollution is omnipresent. In th.s paper, th. major pollutants caused due to wood and non-wood based industries are discussed wh.ch.are th. primary resources of th. forest in spreading th. pollution. In order to study th. impact of industrialization and associated pollution on forest resources, th. system of non-linear ordinary differential equations is formulated. Th. controls are advised on both.types of industries to reduce th. pollution.

关键词： Math.matical Model Pollutants Pollution Forest Resources Wood and Non-Wood Based Industries System of Non-Linear Ordinary Differential Equation Control

Preventions and Controls on Congenital Transmissions of Zika: Math.matical Analysis

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Applied Math.matics 2017年第4期8卷 500-519页

作者： nita h. shah Zalak A. Patel Bijal M. Yeolekar Department of Math.matics Gujarat University Ahmedabad Gujarat India L. D. College of Engineering Ahmedabad Gujarat India

Vector-borne diseases th.eat lives of millions of people in many countries of th. world. Zika is one of th. vector-borne diseases wh.ch.initially spread by th. bite of an infected Aedes species mosquito (Ae. aegypti and Ae. albopictus) and th.n it transmits vertically from a pregnant woman to h.r fetus or from an infected h.man to th.ir sexual partners. Th. congenital transmission of Zika virus (ZIKV) results in new born with.microceph.ly and oth.r neurological abnormalities. Th. control of infected mosquitos is th. best efficient way to control spread of ZIKV. Spraying insecticide is th. safest and easiest way to control mosquitos, but sometimes it is cost worth. for long period of spraying. Controlled prevention from th. vector bites can also h.lp to control disease spread. To control congenital transmission and sexual transmission of ZIKV, preventions sh.uld be taken to reduce/stop pregnancy rate and safe h.terosexual transmission among adults. Also, th.re is no specific treatment available for Zika disease. Treatment is aimed at relieving symptoms with.rest, fluids and medications. Controlled combinations of rest, fluids and medications will h.lp to recover early. As costs are incorporated with.spraying, preventions and treatment, our aim is to minimise th. total cost associated by controlling spraying, preventions and treatment. To fulfil th.s purpose a math.matical model is developed with.disease dynamics in nine compartments namely Susceptible h.man ch.ld, Susceptible h.man male, Susceptible h.man female, Infected h.man ch.ld, Infected h.man male, Infected h.man female, Recovered h.man, Susceptible vector and Infected vector including vertical transmission of Zika disease. Numerical simulations h.ve been carried out to optimise controls, and basic reproduction number and stability are calculated.

关键词： Zika Vertical Transmission Dynamical System Control Stability

Liquor h.bit Transmission Model

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Applied Math.matics 2015年第8期6卷 1208-1213页

作者： nita h. shah Bijal M. Yeolekar Neh.l J. Sh.kla Department of Math.matics Gujarat University Ahmedabad India Department of Math.matics Columbus State University Columbus USA

In th.s paper, we analyse population dynamics of liquor h.bit. Liquor free and Liquor endemic equilibrium are computed. Th. local and global stabilities of th. proposed problem are establish.d. Th. numerical simulatio... 详细信息

关键词： Liquor h.bit Basic Reproduction Number Local Stability Global Stability State-Space Simulation

Linking leaf elemental traits to biomass across forest biomes in th. h.malayas

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Science Ch.na Earth.Sciences 2024年第5期67卷 1518-1528页

作者： nita DYOLA Eryuan LIANG Josep PEÑUELAS J.Julio CAMARERO Sh.lik Ram SIGDEL Sugam ARYAL Wentao LIN Xiang LIU Yongwen LIU Xingliang XU Sergio ROSSI State Key Laboratory of Tibetan Plateau Earth.System Environment and Resources(TPESER)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China University of Ch.nese Academy of Sciences Beijing 100049China Laboratoire sur lesécosystèmes terrestres boréaux Département des Sciences FondamentalesUniversitédu QuébecàChicoutimi555Boulevard de l′UniversitéChicoutimi(QC)G7H2B1Canada CSIC Global Ecology Unit CREAF-CSIC-UABBellaterraE-08193 CataloniaSpain CREAF Cerdanyola del VallèsE-08193 CataloniaSpain Instituto Pirenaico de Ecología(IPE-CSIC) Avenida Montañana 1005Zaragoza 50059Spain Friedrich.Alexander-Universität Erlangen-Nürnberg Institut für GeographieErlangen 91058Germany State Key Laboratory of Grassland Agro-Ecosystems College of EcologyLanzhou UniversityLanzhou 730000China Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China

Plants require a number of essential elements in different proportions for ensuring th.ir growth.and *** elemental concentrations in leaves reflect th. functions and adaptations of plants under specific environmental ***,less is known about h.w th. spectrum of leaf elements associated with.resource acquisition,ph.tosynth.sis and growth.regulates forest biomass along broad elevational *** examined th. influence of leaf element distribution and diversity on forest biomass by analyzing ten elements(C,N,P,K,Ca,Mg,Zn,Fe,Cu,and Mn)in tree communities situated every 100 meters along an extensive elevation gradient,ranging from th. tropical forest(80 meters above sea level)to th. alpine treeline(4200 meters above sea level)in th. Kangch.njunga Landscape in eastern Nepal *** calculated communityweigh.ed averages(reflecting dominant traits governing biomass,i.e.,mass-ratio effect)and functional divergence(reflecting increased trait variety,i.e.,complementarity effect)for leaf elements in a total of 1,859 trees representing 116 *** increasing mass-ratio effect and decreasing complementarity in leaf elements enh.nce forest biomass accumulation.A combination of elements togeth.r with.elevation explains biomass(52.2%of th. variance)better th.n individual elemental trait diversity(0.05%to 21%of th. variance).Elevation modulates trait diversity among plant species in biomass *** promotes biomass at lower elevations,but reduces biomass at h.gh.r elevations,demonstrating an interaction between elevation and *** interaction between elevation and mass-ratio effect produces h.terogeneous effects on biomass along th. elevation *** research.indicates th.t biomass accumulation can be disproportionately affected by elevation due to interactions among trait diversities across vegetation *** h.gh.r trait variation enh.nces th. adaptation of species to environmental ch.nges,it reduces

关键词： Ecosystem function Elevational gradient Functional diversity Functional traits Leaf elements Nich. complementarity

喜马拉雅山不同森林群落主要树种叶片元素性状与生物量之间的关系

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中国科学：地球科学 2024年第5期54卷 1544-1555页

作者： nita DYOLA 梁尔源 Josep PEÑUELAS JJulio CAMARERO Sh.lik Ram SIGDEL Sugam ARYAL 林文涛刘向刘永稳徐兴良 Sergio ROSSI 中国科学院青藏高原研究所青藏高原地球系统与资源环境全国重点实验室北京100101 中国科学院大学北京100049 Laboratoire sur lesécosystèmes terrestres boréaux Département des Sciences FondamentalesUniversitédu QuébecàChicoutimi555Boulevard de l′UniversitéChicoutimi(QC)G7H2B1Canada CSIC Global Ecology Unit CREAF-CSIC-UABBellaterraE-08193 CataloniaSpain CREAF Cerdanyola del VallèsE-08193 CataloniaSpain Instituto Pirenaico de Ecología(IPE-CSIC) Avenida Montañana 1005Zaragoza 50059Spain Friedrich.Alexander-Universität Erlangen-Nürnberg Institut für GeographieErlangen 91058Germany 兰州大学生态学院草种创新与草地农业生态系统全国重点实验室兰州730000 中国科学院地理科学与资源研究所生态系统网络观测与模拟重点实验室北京100101

植物需要多种基本元素调节并保持其特定比例以维持生长发育,叶片元素含量反映了植物的功能及其对环境的适应性.然而,在森林海拔梯度上,我们对于资源获取、光合作用和生长相关的叶片元素如何调节森林生物量仍知之甚少.本研究在喜马拉雅... 详细信息

植物需要多种基本元素调节并保持其特定比例以维持生长发育,叶片元素含量反映了植物的功能及其对环境的适应性.然而,在森林海拔梯度上,我们对于资源获取、光合作用和生长相关的叶片元素如何调节森林生物量仍知之甚少.本研究在喜马拉雅山干城章嘉峰地区沿热带森林(海拔80m)至高山树线(海拔4200m)设置海拔梯度样带,每间隔海拔100m设置一个样点,对116个树种的1859个个体测定了叶片中10种元素(C、N、P、K、Ca、Mg、Zn、Fe、Cu和Mn)的含量,通过计算叶片元素含量的群落加权平均值(反映优势物种的性状优势度,表征质量比效应)和功能离散度(反映物种在生态位空间内的聚集或者离散程度,表征互补效应),探究叶片元素含量及其离散程度沿海拔梯度分异特征,解析其对森林群落生物量的影响.研究结果表明,较强的叶片元素质量比效应和较弱的互补效应有利于森林群落生物量的积累.叶片元素性状多样性与海拔的共同作用对生物量的解释量(解释方差:52.2%)高于元素性状多样性的解释量(解释方差:0.05%~21%).海拔调节了树种性状多样性在生物量积累中的作用,互补效应在低海拔和高海拔地区对生物量的影响分别体现为积极和消极作用,这表明海拔和互补效应之间也存在交互作用.此外,海拔和质量比效应的交互作用对海拔梯度上生物量的影响也存在异质性.本研究表明,不同森林群落生物量的积累可能受到由海拔调控的性状多样性的影响.尽管较高的性状分异不利于生物量的积累,但能增强高海拔地区树种对胁迫环境的适应性.

关键词：生态系统功能海拔梯度功能多样性功能性状叶片元素生态位互补

Multi-zonal transmission dynamics of pandemic COVID-19 and its stability

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Journal of Safety Science and Resilience 2020年第2期1卷 128-134页

作者： nita h.shah Ankush.h.Suth.r Ekta N.Jayswal Department of Math.matics Gujarat UniversityAhmedabad-380009GujaratIndia

At th. end of 2019,th. novel coronavirus(COVID-19)outbreak was identified in Wuh.n city of *** of its profoundly infectious nature,it was converted into a pandemic in a very sh.rt ***,6,291,764 COVID-19 confirmed cases,and a total of 374,359 death. are reported as of 1st June 2020;neverth.less,th. circumstances become more and more critical over *** th.s global pandemic h.s necessitated ex-tensive strategies putting into *** on th. intensity of th. epidemic,th. model discriminates area into th.ee different types of zones,and th.s distinction is crucial to construct various effective strategies for all th.ee types of zones *** th.esh.ld value of th. COVID-19 based on th. data from zone-wise distribution of Indian districts from 15th.April to 3rd May 2020 is ***,th. model is modified in a multi-group model to analyse th. global transmission of *** control th.ory is applied to th. *** control strategies are included based on th. level of intensity of COVID-19.

关键词： COVID-19 Math.matical modelling Stability Control th.ory Numerical simulation

Z-control on dynamics of pollution-allergy model

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Applied Math.matics(A Journal of Ch.nese Universities) 2021年第4期36卷 583-598页

作者： nita h.shah Ankush.h.Suth.r Moksh. h.Satia Ekta N.Jayswal Foram A.Th.kkar Department of Math.matics Gujarat UniversityAhmedabad 380009GujaratIndia

Allergy due to toxic pollutants present in th. environment h.s become a major public h.alth.th.eat affecting th. lives of more th.n one billion people *** prevalence and impact are on th. rise due to urbanization and growing ch.mical industries,on th. oth.r h.nd emerging toxic allergens h.avily impact th. budgets of public h.alth.*** th. current work,th. dynamical model of allergy due to pollution is constructed and ***,th. basic reproduction number is formulated to calculate th. th.esh.ld value of allergic *** model is stabilized locally and globally,besides th. conditions th.t emerged from stability th.ory are used to study th. effects of various parameters.Z-type control mech.nism h.s been used to optimize th. stability of th. *** simulations validate,th.t ch.otic oscillated compartments are stabilized under th. effect of Z-control wh.ch.sh.ws th.t allergic diseases due to th. polluted environment can be controlled.

关键词： allergy due to pollution dynamical system stability Z-type control numerical simulation

Independent and complementary bio-functional effects of CuO andGa_(2)O_(3) incorporated as th.rapeutic agents in silica-and ph.sph.te-based bioactive glasses

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Journal of Materiomics 2022年第4期8卷 893-905页

作者： T.Tite A.C.Popa B.W.Stuart h.R.Fernandes I.M.Ch.rica G.A.Lungu D.Macovei C.Barth. L.Albulescu C.Tanase S.nita N.Rusu D.M.Grant J.M.F.Ferreira G.E.Stan National Institute of Materials Ph.sics MagureleRO-077125Romania Advanced Materials Research.Group Faculty of EngineeringUniversity of NottinghamNG72RDUK CICECOdAveiro Institute of Materials Department of Materials and Ceramics EngineeringUniversity of Aveiro3810-193AveiroPortugal “Victor Babes”National Institute of Research.and Development in Path.logy and Biomedical Sciences BucharestRO-050096Romania National Institute for Ch.mical Ph.rmaceutical Research.and Development BucharestRO-031299Romania

Th. incorporation of th.rapeutic-capable ions into bioactive glasses(BGs),eith.r based on silica(SBGs)or ph.sph.te(PBGs),is currently envisaged as a proficient path.for facilitating bone *** with.th.s view,th. single and complementary structural and bio-functional roles of CuO andGa_(2)O_(3)(in th. 2e5 mol%range)were assessed,by deriving a series of SBG and PBG formulations startingfrom th. parent glass systems,FastOs®BG e 38.5SiO2d36.1CaOd5.6P2O5d19.2MgOd0.6CaF2,and50.0P2O5d35.0CaOd10.0Na_(2)Od5.0 Fe2O_(3)(mol%),respectively,using th. process of *** inter-linked ph.sico-ch.mistry e biological response of BGs was assessed in search.of bio-functional *** ligh. was sh.d on th. structural role e as network former or modifier e ofCu and Ga,immersed in SBG and PBG *** preliminary biological performance was surveyedin vitro by quantification of Cu and Ga ion release under h.meostatic conditions,cytocompatibility assays(in fibroblast cell cultures)and antibacterial tests(against Staph.lococcus aureus).Th. similar(Cu)anddissimilar(Ga)structural roles in th. SBG and PBG vitreous networks governed th.ir ***,Cuions were leach.d in similar concentrations(ranging from 10e35 ppm and 50e110 ppm at BG doses of 5and 50 mg/mL,respectively)for both.type of BGs,wh.le th. release of Ga ions was 1e2 orders ofmagnitude lower in th. case of SBGs(i.e.,0.2e6 ppm)compared to PBGs(i.e.,9e135 ppm).Th.s wasattributed to th. network modifier role of Cu in both.types of BGs,and conversely,to th. network former(SBGs)and network modifier(PBGs)roles of *** glasses were cytocompatible at a dose of 5 mg/mL,wh.le at th. same concentration th. antimicrobial efficiency was found to be accentuated by th. coupledrelease of Cu and Ga ions from *** collective assessment,th. most prominent candidate material forth. furth.r development of implant coatings and bone graft substitutes was delineated as th.38.5SiO2d34.1CaOd5.6P2O5d16.2MgOd

关键词： Bioactive glass Copper Gallium Structure Ion release Antibacterial