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Optimal harvesting for an age-dependent n-dimensional food chain model

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Applied Mathematics and Mechanics(English Edition) 2008年第5期29卷 683-695页

作者：雒志学杜明银 Department of Mathematics Lanzhou Jiaotong University

This paper is concerned with optimal harvesting policy for an age-dependent n-dimensional food chain model. The existence and uniqueness of non-negative solution of the system are proved using the fixed point theorem. By Mazur＇s theorem, the existence of optimal control strategy is demonstrated and optimality conditions derived by means of normal cone.

关键词： food chain age-dependence optimal control the maximum principle

Biotransfer of heavy metals along a soil-plant-insect-chicken food chain:Field study

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Journal of Environmental Sciences 2009年第6期21卷 849-853页

作者： ZHUANG Ping ZOU Huiling SHU Wensheng School of Life Sciences and State Key Laboratory of Biocontrol Sun Yat-sen University Guangzhou 510275 Chin Institute of Ecology South China Botanic Garden Chinese Academy of Sciences Guangzhou 510560 China

The accumulation and transfer of Pb,Zn,Cu,and Cd along a soil-plant-insect-chicken food chain at contaminated sites were *** study site nearing the Pb/Zn mine had been contaminated by heavy metals *** and Pb concentrations steadily declined with increasing trophic level（p 〈 0.01）,but concentrations of Zn and Cu slightly increased from plant to insect larva（p 〉 0.05）.The concentrations of heavy metals were the highest in chicken muscle,with lower values in liver and *** bioaccumulation of Pb was observed in chicken *** eliminations of Pb,Zn,Cu,and Cd via insect and chicken feces avoid metal bioaccumulation in insect and chicken *** results suggest that the accumulation of heavy metals in specific animal organ of tissues could not be neglected,although transfer of metals to chicken from plant and insect was limited.

关键词： heavy metal food chain insect chicken field study

Comparison between two tritrophic food chain models with multiple delays and anti-predation effect

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International Journal of Biomathematics 2021年第3期14卷 53-100页

作者： Debgopal Sahoo G.P.Samanta Department of Mathematics Indian Institute of Engineering Science and Technology Shibpur Howrah-711103India

Exploring the predator prey linkage in food chain system is the most familiar research work in population ***,some research experiments show that predator-prey interaction not only governed by direct hunting but also influenced by some indirect effect such as fear effect(felt by prey)that may change the physiological behavior of *** upon this fact,we consider a tritrophic food chain model incorporating with anti-predation response(fear effect)and multiple time delays for biomass conversion from prey to middle predator and middle to top *** analyze the resulting delay differential equations and explore how the anti-predation response level affects the population *** also investigate the effect of delay parameters,for which the model system switches its stability through *** compare all of our results between two different food chain models consisting of two different functional *** numerical simulations are performed to validate the effectiveness of the derived theoretical results.

关键词： food chain functional response anti-predation response digestion delay Hopf-bifurcation

Preventing Hg Transference from Soil to Terrestrial food chain

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Pedosphere 1993年第1期3卷 67-73页

作者： QINGCHANG－LE MOUSHU－SEN SouthwestAgriculturalUniversity Chaingqing630716（China） SouthwestAgriculturalUniversity Chaingqing630

Hg in acid soil could be activited by liming and become available to plant, if excessive or insufficient amount of lime was applied. The changes of Hg activity in acid soil with different rates of CaCO3 amendment Were studied by a pot experiment. To predict the adequate amount of lime application, a simple method using the pH (EDTA) as an indicator was suggested. The suitable range of lime application was the amount of lime addition when the pH of soil-EDTA system *** to 4.0-4.3.

关键词： food chain mercury terrestrial transference

The Risk of <i>Fusarium</i>and Their Mycotoxins in the food chain

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Advances in Microbiology 2021年第10期11卷 541-553页

作者： Elisaveta Sandulachi Aliona Ghendov-Mosanu Daniela Cojocari Rodica Sturza Department of food Technology Technical University of Moldova Chisinau Republic of Moldova Department of Preventive Medicine “Nicolae Testemitanu” State University of Medicine and Pharmacy Chisinau Republic of Moldova Department of Oenology and Chemistry Technical University of Moldova Chisinau Republic of Moldova

Fusarium sp. and mycotoxins of these species pose a major risk to consumer health, agriculture and the food industry. This paper is a worldwide bibliographic study on impact of Fusarium and mycotoxins on the food chain. The factors influencing the development of fungi Fusarium sp., the formation of mycotoxins and their microbiological risk on the food chain must be considered as a whole. For cereals and oilseeds before and after harvest, fungal infections and mycotoxin contamination present serious problems worldwide. This paper is an overview of the factors that include the microbiological risk and impact of Fusarium in the food chain mentioned in national and international studies. The methods and results obtained in this direction internationally are mentioned, such as: infrared spectroscopy, Raman spectrometry and hyperspectral imaging. Also, in review are presented solutions to reduce this impact on the food chain.

关键词： Fusarium sp. Mycotoxins food chain Management Systems in Agriculture and food Industry food Safety

Trophic transfer of nanoparticles in food chain:A review

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Trophic transfer of nanoparticles in food chain:A review

Bifurcation analysis of a food chain system incorporating time delay and the disease spreading among prey species

全国环境纳米技术及生物效应学术研讨会

作者： Gaozhong Pu Guangping Xu Chengxin He Yuqing Huang Guangxi Key Laboratory of Plant Conservation and Restoration Ecology in Karst Terrain Guangxi Institue of BotanyGuangxi Zhuang Autonomous Region and Chinese Academy of Sciences

Nanoparticles from the rapidly increasing number of consumer products have led to concerns about the health risks and environmental impacts of such nanosized materials. One of the most significant and currently not well-understood risks is their potential transfer and magnification in food chains. The present review summarizes and evaluates the characters of nanoparticles, the mechanism, impact factors and models of bioaccumulation and biomagnification of nanoparticles in both terrestrial and aquatic food chain. Differences of these nanoparticles physiological parameters in different groups of terrestrial or aquatic animals are discussed. The potential trophic transfer factor of nanoparticles along terrestrial or aquatic food chains can be predicted based on a simple kinetic equation by incorporating nanoparticles assimilation efficiency（AE）, nanoparticles efflux rate and ingestion activity of the animals. In general, during the transfer of nanoparticles along food chain, whether the concentration of nanoparticles will be biological amplification or dilution, depending on the different food chains and different nanoparticles. Although there are some studies of the bioaccumulation and biomagnification of nanoparticles in food chain, which mostly researched trophic transfer of nanoparticles in a simplified food chain, only a few researchers focused their studies on the integrity food chain. Furthermore, the physicochemical properties of nanoparticles in controlling food chain transfer are generally considered in many past studies, we suggest that the physiological and biochemical processes need to be emphasized in any future study. Therefore, it is necessary to study the bioaccumulation and biomagnification, as well as the related treatment models of nanoparticles in food chain since there are more and more applications of nanoparticles in various fields.

关键词： food chain Nanoparticles Biomagnification Trophic transfer Nanoecotoxicology

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Bifurcation analysis of a food chain system incorporating ti...

Molecular game theory for a toxin-dominant food chain model

第30届中国控制与决策会议

作者： Xinyou Meng Nini Qin Department of Applied Mathematics Lanzhou University of Technology

In this paper,a food chain system incorporating time delay and the disease spreading among prey species is *** positive of such system is *** the presence of time delay,some sufficient conditions of the local stability of the positive equilibrium and the existence of Hopf bifurcation are obtained by analyzing the corresponding characteristic equation,and the properties of Hopf bifurcation are showed by using the normal form theory and center manifold *** simulations are given to support our analytical results.

关键词： food chain Eco-epidemiology Hopf bifurcation Delay

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Molecular game theory for a toxin-dominant food chain model

Biological transfer of silver under silver nanoparticle exposure and nitrogen transfer via a collembolan- predatory mite food-chain and ecotoxicity of silver sulfide

第十四届生物毒素毒理学术大会暨第一届生物毒素——从生存...

作者： Bowen Li Jonathan R.Silva Xiancui Lu Lei Luo Anna Luo Fan Yang Jianmin Cui Shilong Yang Ren Lai Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences and Yunnan Province Kunming Institute of Zoology Key Laboratory of Bioactive Peptides of Yunnan Province Kunming Institute of Zoology Department of Biomedical Engineering Center for the Investigation of Membrane Excitability DiseasesWashington University in St Louis Key Laboratory of Medical Neurobiology Department of Biophysics and Kidney Disease CenterFirst Affiliated HospitalInstitute of NeuroscienceNational Health Commission and Chinese Academy of Medical SciencesZhejiang University School of Medicine

A general concept is established that animal toxins are used to subdue prey and deter predators,which act as the key drivers in natural food chains and ***,the predators of venomous animals may exploit feeding adaptation strategies to overcome the toxin burdens placed by their *** remains unknown about the genetic and molecular game process in the toxindominant food chain *** we show an evolutionary strategy in different trophic levels of scorpion-eating amphibians,scorpions,and insects,representing each predation relationship in this type of habitat,which is dominated by paralytic toxins of *** scorpion preying on insects,we found that the scorpion a-toxins irreversibly activate skeletal muscle sodium channel of their prey（insect,BgNaV1） through a membrane delivery mechanism and an efficient binding with the Asp/LysTyr motif of ***,in the predatory game between frogs and scorpions,with a single point mutation（Lys to Glu） in this motif of frog’s skeletal muscle sodium channel（fNaV1.4）,fNaV1.4 breaks this interaction and diminishes muscular toxicity to the frog,thus regularly preying on scorpions without showing ***,this molecular strategy has also been employed by some other scorpion-eating amphibians,especially *** contrast to these amphibians,the Asp/Lys-Tyr motifs are structurally and functionally conserved in other animals which do not prey on ***,our findings elucidate the protein-protein interacting mechanism of a toxin-dominant predator-prey system,implying the evolutionary game theory at molecular level.

关键词： Game Theory Sodium Channel Scorpion Amphibia food chain

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Soil Ecology Letters 2022年第4期4卷 435-443页

作者： Simin Li Zhu Li Xin Ke Longhua Wu Peter Christie CAS Key Laboratory of Soil Environment and Pollution Remediation Institute of Soil ScienceChinese Academy of SciencesNanjing 210008China University of Chinese Academy of Sciences Beijing 100049China Institute of Plant Physiology and Ecology Shanghai Institutes for Biological SciencesChinese Academy of SciencesShanghai 200032China

The development of nanotechnology has accelerated the use of silver nanoparticles(AgNPs)in household chemicals and the accumulation of Ag in sewage treatment *** application of sewage sludge products to soils raises concerns over the safety of Ag in the function and biogeochemical cycles of the soil belowground ***,we assess the potential risk of the accumulation and transfer of Ag under AgNPs exposure and its effects on the trophic transfer of nitrogen(N)through a soil animal food chain(Folsomia candida–Hypoaspis aculeifer).The formation of stable silver sulfide(Ag_(2)S)was also studied via a single species test using *** of Ag in *** increased with increasing AgNPs concentration,as did those in the predator ***,but the Ag bioaccumulation factors of both animals were<*** candida body tissue 15 N abundance declined markedly compared with that of *** sulfide did have adverse effects on the survival and reproduction of *** Ag concentrations of *** increased with increasing Ag_(2)S concentration in sludge-treated *** sulfide showed ecotoxicity to the collembolan,therefore ecotoxicity resulting from the transformation and fate of AgNPs in soils needs to be considered before biosolid products are applied to agricultural soils.

关键词： AgNPs Ag_(2)S 15N Soil animals food chain