检索结果-南通市图书馆

Z-control on dynamics of pollution-allergy model

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics(A Journal of Chinese Universities) 2021年第4期36卷 583-598页

作者： nita h.shah Ankush h.Suthar Moksha h.Satia Ekta N.Jayswal Foram A.Thakkar Department of Mathematics Gujarat UniversityAhmedabad 380009GujaratIndia

Allergy due to toxic pollutants present in the environment has become a major public health threat affecting the lives of more than one billion people *** prevalence and impact are on the rise due to urbanization and growing chemical industries,on the other hand emerging toxic allergens heavily impact the budgets of public health *** the current work,the dynamical model of allergy due to pollution is constructed and ***,the basic reproduction number is formulated to calculate the threshold value of allergic *** model is stabilized locally and globally,besides the conditions that emerged from stability theory are used to study the effects of various parameters.Z-type control mechanism has been used to optimize the stability of the *** simulations validate,that chaotic oscillated compartments are stabilized under the effect of Z-control which shows that allergic diseases due to the polluted environment can be controlled.

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

Linking leaf elemental traits to biomass across forest biomes in the himalayas

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2024年第5期67卷 1518-1528页

作者： nita DYOLA Eryuan LIANG Josep PEÑUELAS J.Julio CAMARERO Shalik 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 Chinese 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 their growth and *** elemental concentrations in leaves reflect the functions and adaptations of plants under specific environmental ***,less is known about how the spectrum of leaf elements associated with resource acquisition,photosynthesis and growth regulates forest biomass along broad elevational *** examined the 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 the tropical forest(80 meters above sea level)to the alpine treeline(4200 meters above sea level)in the Kangchenjunga Landscape in eastern Nepal *** calculated communityweighted 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 enhance forest biomass accumulation.A combination of elements together with elevation explains biomass(52.2%of the variance)better than individual elemental trait diversity(0.05%to 21%of the variance).Elevation modulates trait diversity among plant species in biomass *** promotes biomass at lower elevations,but reduces biomass at higher elevations,demonstrating an interaction between elevation and *** interaction between elevation and mass-ratio effect produces heterogeneous effects on biomass along the elevation *** research indicates that biomass accumulation can be disproportionately affected by elevation due to interactions among trait diversities across vegetation *** higher trait variation enhances the adaptation of species to environmental changes,it reduces

关键词： Ecosystem function Elevational gradient Functional diversity Functional traits Leaf elements Niche 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

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

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 Shalik 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

Influence of Slope Angle on the Walking of Passive Dynamic Biped Robot

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics 2015年第3期6卷 456-465页

作者： nita h. shah Mahesh A. Yeolekar Department of Mathematics Gujarat University Ahmedabad India Amiraj College of Engineering & Technology Gujarat Technological University Ahmedabad India

In this paper, we modeled a simple planer passive dynamic biped robot without knee with point feet. This model has a stable, efficient and natural periodic gait which depends on the values of parameters like slope angle of inclined ramp, mass ratio and length ratio. The described model actually is an impulse differential equation. Its corresponding poincare map is discrete case. With the analysis of the bifurcation properties of poincare map, we can effectively understand some feature of impulse model. The ideas and methods to cope with this impulse model are common. But, the process of analysis is rigorous. Numerical simulations are reliable.

关键词： Biped Robot Limit Cycle Walking Passive Dynamic Walking Poincare Map Orbital Stability Bifurcation

SEIR Model and Simulation for Vector Borne Diseases

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics 2013年第8期4卷 13-17页

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

An epidemic model is a simplified means of describing the transmission of infectious diseases through individuals. The modeling of infectious diseases is a tool which has been used to study the mechanisms by which diseases spread, to predict the future course of an outbreak and to evaluate strategies to control an epidemic. Epidemic models are of many types. here, SEIR model is discussed. We first discuss the basics of SEIR model. Then it is applied for vector borne diseases. Steady state conditions are derived. A threshold parameter R0 is defined and is shown that the disease will spread only if its value exceeds 1. We have applied the basic model to one specific diseases-malaria and did the sensitivity analysis too using the data for India. We found sensitivity analysis very important as it told us the most sensitive parameter to be taken care of. This makes the work more of practical use. Numerical simulation is done for vector and host which shows the population dynamics in different compartments.

关键词： SEIR-Model Vector Borne Disease Malaria Simulation

Optimum Control for Spread of Pollutants through Forest Resources

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics 2017年第5期8卷 607-620页

作者： nita h. shah Moksha h. Satia Bijal M. Yeolekar Department of Mathematics Gujarat University Ahmedabad India

Pollution has become the most critical factor spread by forest resources through wood-based and non-wood based industries. In other words, pollution is omnipresent. In this paper, the major pollutants caused due to wood and non-wood based industries are discussed which are the primary resources of the forest in spreading the pollution. In order to study the impact of industrialization and associated pollution on forest resources, the system of non-linear ordinary differential equations is formulated. The controls are advised on both types of industries to reduce the pollution.

关键词： Mathematical 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: Mathematical Analysis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics 2017年第4期8卷 500-519页

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

Vector-borne diseases threat lives of millions of people in many countries of the world. Zika is one of the vector-borne diseases which initially spread by the bite of an infected Aedes species mosquito (Ae. aegypti and Ae. albopictus) and then it transmits vertically from a pregnant woman to her fetus or from an infected human to their sexual partners. The congenital transmission of Zika virus (ZIKV) results in new born with microcephaly and other neurological abnormalities. The control of infected mosquitos is the best efficient way to control spread of ZIKV. Spraying insecticide is the safest and easiest way to control mosquitos, but sometimes it is cost worthy for long period of spraying. Controlled prevention from the vector bites can also help to control disease spread. To control congenital transmission and sexual transmission of ZIKV, preventions should be taken to reduce/stop pregnancy rate and safe heterosexual transmission among adults. Also, there 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 help to recover early. As costs are incorporated with spraying, preventions and treatment, our aim is to minimise the total cost associated by controlling spraying, preventions and treatment. To fulfil this purpose a mathematical model is developed with disease dynamics in nine compartments namely Susceptible human child, Susceptible human male, Susceptible human female, Infected human child, Infected human male, Infected human female, Recovered human, Susceptible vector and Infected vector including vertical transmission of Zika disease. Numerical simulations have 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 habit Transmission Model

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics 2015年第8期6卷 1208-1213页

作者： nita h. shah Bijal M. Yeolekar Nehal J. Shukla Department of Mathematics Gujarat University Ahmedabad India Department of Mathematics Columbus State University Columbus USA

In this paper, we analyse population dynamics of liquor habit. Liquor free and Liquor endemic equilibrium are computed. The local and global stabilities of the proposed problem are established. The numerical simulatio... 详细信息

关键词： Liquor habit Basic Reproduction Number Local Stability Global Stability State-Space Simulation

^(13)C-methacetin breath test reproducibility study reveals persistent CYP1A2 stimulation on repeat examinations

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2011年第45期17卷 4979-4986页

作者： Anna Kasicka-Jonderko Anna nita Krzysztof Jonderko Magdalena Kamińska Barbara Bońska-Fajfrowska Department of Basic Biomedical Science School of Pharmacy Medical University of Silesia

AIM: To find the most reproducible quantitative parameter of a standard 13C-methacetin breath test (13C-MBT). METhODS: Twenty healthy volunteers (10 female, 10 male) underwent the 13C-MBT after intake of 75 mg 13C-methacetin p.o. on three occasions. Short-and medium-term reproducibility was assessed with paired examinations taken at an interval of 2 and 18 d (medians), respectively. RESULTS: The reproducibility of the 1-h cumulative 13C recovery (AUC0-60), characterized by a coefficient of variation of 10%, appeared to be considerably better than the reproducibility of the maximum momentary 13C recovery or the time of reaching it. Remarkably, as opposed to the short gap between consecutive examinations, the capacity of the liver to handle 13C-methacetin increased slightly but statistically significantly when a repeat dose was administered after two to three *** the AUC0-60, the magnitude of this fixed bias amounted to 7.5%. Neither the time gap between the repeat examinations nor the gender of the subjects affected the 13C-MBT reproducibility. CONCLUSION: 13C-MBT is most reproducibly quantified by the cumulative 13C recovery, but the exactitude thereof may be modestly affected by persistent stimulation of CYP1A2 on repeat examinations.

关键词： 13C-Methacetin Breath test Isotope application in medicine Liver Reproducibility