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competition of insect decomposers over large vertebrate carrion:Necrodes beetles(Silphidae)*** flies(Calliphoridae)

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Current Zoology 2022年第6期68卷 645-656页

作者： Szymon MATUSZEWSKI Anna MADRA-BIELEWICZ Laboratory of Criminalistics Adam Mickiewicz UniversityPoznan 61-809Poland Wielkopolska Centre for Advanced Technologies Adam Mickiewicz UniversityPoznan 61-614Poland

Large carrion is inhabited by highly variable and interactive communities of *** interactions in carrion insect communities have been recently the focus in carrion *** contrast,competition between carrion insects is rather *** we provide evidence that blow flies(Calliphoridae)and Necrodes beetles(Silphidae),dominant decomposers of large carcasses in terrestrial habitats,compete over *** reanalyzing the results from 90 pig carcasses,we demonstrated that the contribution of the flies and the beetles to the decay was negatively *** greater part of the large carrion pool was monopolized by blow flies,whereas Necrodes beetles abundantly colonized carcasses,on which blow flies were less effective as *** behavioral assays,we found that adult beetles killed 4 times more frequently feeding than postfeeding third instar larvae of the flies,with the large decrease in the killing frequency after the larvae reached the age of early third ***,adult Necrodes beetles preferentially killed the larvae that were before or in their peak *** study provides evidence that the interaction between blow flies and Necrodes beetles is a combination of indirect exploitative effects of the flies and direct interference effects of the beetles(the mixed competition).

关键词： carrion competition interspecific interactions

competition and abiotic stress affect the size of mangroves near their geographic range limit

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Journal of Plant Ecology 2022年第1期15卷 129-140页

作者： Dan Peng Hongyu Guo Anna R.Armitage Steven C.Pennings Department of Biology and Biochemistry University of HoustonHoustonTX 77204USA Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems College of the Environment and EcologyXiamen UniversityXiamen 361102China Tianjin Key Laboratory of Animal and Plant Resistance College of Life SciencesTianjin Normal UniversityTianjin 300387China Department of Marine Biology Texas A&M University at GalvestonGalvestonTX 77553USA

Studies of competition in mangroves are mostly limited to seedlings and artificial settings like forestry *** conducted the first experimental study of intraspecific competition among adult mangroves in a natural mangrove forest to examine how important competition is in determining tree size compared with abiotic *** conducted a study near Port Aransas,TX,USA,which is near the geographical limit of mangroves and dominated by monospecific stands of‘scrub’form black mangroves,Avicennia *** thinned 10 plots to create a gradient of mangrove cover,and quantified the effects of mangrove cover on the growth of tagged mangroves from 2013 to 2019,and the mangrove canopy height in *** relative growth rate of tagged mangroves declined as mangrove cover increased,and plants in the plot with 100%mangrove cover did not grow,indicating that they had attained their maximum *** plots with reduced mangrove cover,plant height increased sharply,with plants in the plot with 11%mangrove cover growing~52%taller over 6 *** height was~30%taller in the plot fringe than in the interior,and canopy height in both fringe and interior declined as mangrove cover *** of leaf chlorophyll concentration and light interception suggested that plants were primarily limited by *** results showed that scrub mangroves compete strongly despite being limited by abiotic conditions,and that the importance of competition was greater in magnitude than that of abiotic differences between the fringe and interior.

关键词： competition adult mangrove nutrient limitation growth response scrub mangrove geographical limit

competition,spatial pattern,and regeneration of Haloxylon ammodendron and Haloxylon persicum communities in the Gurbantunggut Desert,Northwest China

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Journal of Arid Land 2022年第10期14卷 1138-1158页

作者： LIU Yaxuan ZENG Yong YANG Yuhui WANG Ning LIANG Yuejia Xinjiang Laboratory of Lake Environment and Resources in Arid Zone Urumqi 830054China College of Geographic Science and Tourism Xinjiang Normal UniversityUrumqi 830054China School of Geography and Tourism Shaanxi Normal UniversityXi'an 710119China

competition,spatial pattern,and regeneration are important factors affecting community composition,structure,and *** this study,we surveyed 300 quadrats from three dunes(i.e.,fixed dunes,semifixed dunes,and mobile dunes)in the Gurbantunggut Desert,Northwest China,from late May to early June in *** intraspecific and interspecific competition,spatial pattern,and regeneration of Haloxylon ammodendron and Haloxylon persicum were studied using the Hegyi competition index and point pattern analysis *** results showed that the optimal competition distance of the objective tree in the *** and *** communities was 6 *** intraspecific and interspecific competition of *** was the greatest in fixed dunes,while the competition intensity of *** in semifixed dunes and mobile dunes was greater than that in fixed *** order of competition intensity of the two populations was seedlings>saplings>adults,and the competition intensity gradually decreased with the increase in plant *** spatial distribution pattern of the three life stages of *** and *** was random,and there were no correlations between seedlings and saplings,adults and saplings,and seedlings and *** density of regenerated seedlings and saplings of *** in the three dunes followed the order of fixed dunes>semifixed dunes>mobile dunes,and that of *** in the three dunes followed the order of mobile dunes>semifixed dunes>fixed ***,when artificially planting *** and *** for sand control,the planting interval should be 6 m,and seedlings should be planted next to adults to minimize the competition between plants,which can promote the renewal of *** and *** and the stabilization of the ecosystem.

关键词： competition spatial pattern regeneration Haloxylon ammodendron Haloxylon persicum Gurbantunggut Desert

competition and body size in plants:the between-species tradeoff for maximum potential versus minimum reproductive threshold size

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Journal of Plant Ecology 2011年第3期4卷 115-122页

作者： Amanda J.Tracey Lonnie W.Aarssen Department of Biology Queen’s UniversityKingstonON K7L 3N6Canada

Aims According to traditional theory,superior competitive ability in plants generally requires relatively large plant body *** even within the most crowded vegetation,most resident species are relatively small;species size distributions are right-skewed at virtually every *** examine a potential explanation for this paradox:small species coexist with and outnumber large species because they have greater‘reproductive economy’,*** are better equipped—and hence more likely—to produce offspring despite severe size suppression from intense *** Randomly placed plots within old-field vegetation were surveyed across the growing *** each plot,the largest(MAX)and smallest(MIN)reproductive individuals of each resident species were collected for above-ground dry mass *** tested three hypotheses:(i)smaller resident species(with smaller MAX size)have generally smaller reproductive threshold sizes;(ii)smaller resident species have greater‘reproductive economy’,i.e.a smaller MIN relative to MAX reproductive plant size;and(iii)MIN size predicts plot occupancy(species abundance within the community)better than MAX *** Findings The results supported the first and third,but not the second ***,we could not reject the hypothesis that smaller species have greater reproductive economy,as it was not possible to record data for the largest potential plant size for each species—since even the largest(MAX)plants collected from our sampled plots were subjected to competition from neighbours under these natural field ***,contrary to conventional competition theory,more successful species(in terms of greater plot occupancy)had smaller minimum not larger(or smaller)maximum reproductive *** results suggest that a small reproductive threshold size,commonly associated with relatively small potential body size,is generally more effective in transmitting genes into future generations when selection

关键词： competition coexistence fitness old-field d reproductive economy species size distribution

Strategic Cooperation with Differential Suppliers' Ability under Downstream competition in Complex Products Systems

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Journal of Systems Science and Systems Engineering 2019年第4期28卷 449-477页

作者： Jinhua Zhou Jianjun Zhu Hehua Wang College of Economics and Management Nanjing University of Aeronautics and Astronautics Nanjing 211106 China School of Business Jinling Institute of TechnologyNanjing 211169 China

This paper investigates the strategic cooperation of two competitive suppliers with different abilities and a weak main manufacturer in Complex Products Systems (CoPS), where a main manufacturer signs a revenue-sharing contract based on a relationship-specific investment with the stronger supplier. The stronger supplier provides one key element to the main manufacturer and encroaches on the downstream market by producing substitutable final products simultaneously. We consider multi-period decisions, by building different models based on centralized, decentralized, and cooperative decisions. The equilibrium strategies are characterized under downstream competition, and optimal cooperation strategies are derived by building multi-period game models. The results show that strong cooperation can enhance the economic performance of each individual as well as the whole supply chain. The weak main manufacturer would face the risk of strong suppliers' supply interruptions when the competitive degree of suppliers and downstream competition are fierce enough under decentralized decisions. Additionally, the gap in the abilities of the two competitive suppliers reduces the main manufacturer's profitability. However the revenue-sharing contract based on a relationship-specific investment can motivate the strong supplier to establish cooperation relationship and improve both stakeholders' profitability. Moreover, strategic cooperation is efficient to prevent the strong supplier encroaching on downstream and has a positive impact on boosting the weak main manufacturer's market share. Meanwhile, nurturing a domestic supplier is an effective measure for improving competitiveness and indigenous technological capability of the main manufacturer in CoPS. Finally, some useful management sights on cooperation strategy and optimal decisions are derived.

关键词： Cooperation downstream competition CoPS contract coordination suppliers' ability

A Memetic Algorithm With competition for the Capacitated Green Vehicle Routing Problem

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IEEE/CAA Journal of Automatica Sinica 2019年第2期6卷 516-526页

作者： Ling Wang Jiawen Lu the Department of Automation Tsinghua University

In this paper, a memetic algorithm with competition(MAC) is proposed to solve the capacitated green vehicle routing problem(CGVRP). Firstly, the permutation array called traveling salesman problem(TSP) route is used to encode the solution, and an effective decoding method to construct the CGVRP route is presented accordingly. Secondly, the k-nearest neighbor(k NN) based initialization is presented to take use of the location information of the customers. Thirdly, according to the characteristics of the CGVRP, the search operators in the variable neighborhood search(VNS) framework and the simulated annealing(SA) strategy are executed on the TSP route for all solutions. Moreover, the customer adjustment operator and the alternative fuel station(AFS) adjustment operator on the CGVRP route are executed for the elite solutions after competition. In addition, the crossover operator is employed to share information among different solutions. The effect of parameter setting is investigated using the Taguchi method of design-ofexperiment to suggest suitable values. Via numerical tests, it demonstrates the effectiveness of both the competitive search and the decoding method. Moreover, extensive comparative results show that the proposed algorithm is more effective and efficient than the existing methods in solving the CGVRP.

关键词： Capacitated green vehicle routing problem(CGVRP) competition k-nearest neighbor(kNN) local intensification memetic algorithm

Cooperation and competition Strategy Analysis of Decision-Making Units Based on Efficiency Game

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Journal of Systems Science and Systems Engineering 2020年第2期29卷 235-248页

作者： Li Cao Zhanxin Ma Muren School of Mathematics Science Inner Mongolia UniversityHohhot 010021China College of Computer and Information Inner Mongolia Medical UniversityHohhot 010051China School of Economics and Management Inner Mongolia UniversityHohhot 010021China Key Laboratory of Rail Transit Beijing Jiaotong UniversityBeijing 100044China School of Economics and Management Inner Mongolia University of TechnologyHohhot 010110 China

Data envelopment analysis(DEA)method based on game theory effectively ranks the decisionmaking units(DMUs)by the view of cooperation or *** DEA method based on partial ordered set theory depicts the relationships among ***,these methods are unable to reveal the complex cooperation and competition relationships among *** this paper,an optimal model for DMU group game strategy is proposed based on the generalized DEA method and game *** to this model,we can effectively depict the efficiency change of ***,the effect of various game relationships on individual and the union of DMUs can be *** is of positive significance for decision makers to find partners and moderate the cooperation and competition situation of their ***,the cooperation and competition relationships of 9 express enterprises in a certain area in China are analyzed by using the method proposed in this paper.

关键词： Generalized DEA game theory cross efficiency cooperation and competition

Spacecraft collision avoidance challenge:Design and results of a machine learning competition

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Astrodynamics 2022年第2期6卷 121-140页

作者： Thomas Uriot Dario Izzo Luís FSimões Rasit Abay Nils Einecke Sven Rebhan Jose Martinez-Heras Francesca Letizia Jan Siminski Klaus Merz The European Space Agency Noordwijk2201 AZthe Netherlands ML Analytics LisbonPortugal FuturifAI CanberraAustralia Honda Research Institute Europe GmbH Offenbach 63073Germany ESOC Space Debris OfficeDarmstadt 64293Germany

Spacecraft collision avoidance procedures have become an essential part of satellite *** and constantly updated estimates of the collision risk between orbiting objects inform various operators who can then plan risk mitigation *** measures can be aided by the development of suitable machine learning(ML)models that predict,for example,the evolution of the collision risk over *** October 2019,in an attempt to study this opportunity,the European Space Agency released a large curated dataset containing information about close approach events in the form of conjunction data messages(CDMs),which was collected from 2015 to *** dataset was used in the Spacecraft Collision Avoidance Challenge,which was an ML competition where participants had to build models to predict the final collision risk between orbiting *** paper describes the design and results of the competition and discusses the challenges and lessons learned when applying ML methods to this problem domain.

关键词： space debris collision avoidance competition kelvins

Diet shift in bank voles induced by competition from grey-sided voles?

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Integrative Zoology 2019年第4期14卷 376-382页

作者： Magnus MAGNUSSON Gustaf SAMELIUS Birger HÖRNFELDT Frauke ECKE Department of Wildlife Fishand Environmental StudiesSwedish University of Agricultural SciencesUmeåSweden 2Snow Leopard Trust SeattleUSA Department of Ecology Swedish University of Agricultural SciencesRiddarhyttanSweden

Grey-sided voles(Myodes rufocanus)and bank voles(Myodes glareolus)co-exist in boreal forests in northern *** studies suggest that the 2 species interact interspecifically,the grey-sided vole being the dominant *** tested the hypothesis that bank voles shift their diet due to competition with the dominant grey-sided vole by studying stable isotope ratios in both *** samples were taken from voles in patches of old forest occupied by only bank voles and patches of old forest occupied by both grey-sided voles and bank *** found that:(i)stable isotope ratios of bank voles differed in areas with and without grey-sided voles;and that(ii)the stable isotope ratios of bank voles were more similar to those of grey-sided voles in areas where grey-sided voles were *** data suggests that grey-sided voles forced bank voles to change their diet due to interspecific competition.

关键词： competition diet shift Myodes glareolus Myodes rufocanus stable isotopes