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Global leaf nitrogen and phosphorus stoichiometry and their scaling exponent

National Science Review 2018年第5期5卷 728-739页

作者： Di Tian Zhengbing Yan Karl J.Niklas Wenxuan Han jens kattge Peter B.Reich Yongkai Luo Yahan Chen Zhiyao Tang Huifeng Hu Ian J.Wright Bernhard Schmid Jingyun Fang Institute of Ecology College of Urban and Environmental Sciencesand Key Laboratory for Earth Surface Processes of the Ministry of EducationPeking University Max-Planck-Institute for Biogeochemistry State Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of Sciences College of Life Sciences Capital Normal University Department of Plant Biology Cornell University Department of Forest Resources University of Minnesota Department of Biological Sciences Macquarie UniversitySydneyNSW 2109Australia10 Department of Evolutionary Biology and Environmental StudiesUniversity of Zurich Hawkesbury Institute for the Environment Western Sydney University Key Laboratory of Plant-Soil Interactions Ministry of EducationCollege of Resources and Environmental SciencesChina Agricultural University

Leaf nitrogen(N) and phosphorus(P) concentrations constrain photosynthetic and metabolic processes,growth and the productivity of plants. Their stoichiometry and scaling relationships regulate the allocation of N and P from subcellular to organism, and even ecosystem levels, and are crucial to the modelling of plant growth and nutrient cycles in terrestrial ecosystems. Prior work has revealed a general biogeographic pattern of leaf N and P stoichiometric relationships and shown that leaf N scales roughly as two-thirds the power of P. However, determining whether and how leaf N and P stoichiometries, especially their scaling exponents, change with functional groups and environmental conditions requires further verification. In this study, we compiled a global data set and documented the global leaf N and P concentrations and the N:P ratios by functional group, climate zone and continent. The global overall mean leaf N and P concentrations were 18.9 mg gand 1.2 mg g, respectively, with significantly higher concentrations in herbaceous than woody plants(21.72 mg gvs. 18.22 mg gfor N; and 1.64 mg gvs. 1.10 mg gfor P). Both leaf N and P showed higher concentrations at high latitudes than low latitudes. Among six continents, Europe had the highest N and P concentrations(20.79 and 1.54 mg g) and Oceania had the smallest values(10.01 and 0.46 mg g). These numerical values may be used as a basis for the comparison of other individual studies. Further, we found that the scaling exponent varied significantly across different functional groups,latitudinal zones, ecoregions and sites. The exponents of herbaceous and woody plants were 0.659 and0.705, respectively, with significant latitudinal patterns decreasing from tropical to temperate to boreal zones. At sites with a sample size ≥10, the values fluctuated from 0.366 to 1.928, with an average of *** factors including the intrinsic attributes of different life forms, P-related growth rates and relative nutrient availa

关键词： leaf nitrogen phosphorus stoichiometry scaling exponent functional group biogeography

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Family-level leaf nitrogen and phosphorus stoichiometry of global terrestrial plants

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Science China(Life Sciences) 2019年第8期62卷 1047-1057页

作者： Di Tian Zhengbing Yan Suhui Ma Yuehong Ding Yongkai Luo Yahan Chen Enzai Du Wenxuan Han Emoke Dalma Kovacs Haihua Shen Huifeng Hu jens kattge Bernhard Schmid Jingyun Fang College of Life Sciences Capital Normal UniversityBeijing100048China Institute of Ecology College of Urban and Environmental Sciencesand Key Laboratory for Earth Surface Processes of the Ministry ofEducationPeking UniversityBeijing100871China State Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of SciencesBeijing100093China College of Resources Science&Technology and State Key Laboratory of Earth Surface Processes and Resource EcologyBeijing NormalUniversityBeijing100875China Key Laboratory of Plant-Soil Interactions Ministry of EducationCollege of Resources and Environmental SciencesChina AgriculturalUniversityBeijing100193China National Institute for Research and Development in Optoelectronics INCDO-INOE2000 Research Institute for Analytical InstrumentationICIA subsidiaryCluj-Napoca400293Romania Max-Planck-Institute for Biogeochemistry Jena07745Germany Department of Evolutionary Biology and Environmental Studies University of ZurichZurich8057Switzerland

Leaf nitrogen(N) and phosphorus(P) concentrations are critical for photosynthesis, growth, reproduction and other ecological processes of plants. Previous studies on large-scale biogeographic patterns of leaf N and P stoichiometric relationships were mostly conducted using data pooled across taxa, while family/genus-level analyses are rarely reported. Here, we examined global patterns of family-specific leaf N and P stoichiometry using a global data set of 12,716 paired leaf N and P records which includes 204 families, 1,305 genera, and 3,420 species. After determining the minimum size of samples(i.e., 35 records), we analyzed leaf N and P concentrations, N:P ratios and N^P scaling relationships of plants for 62 families with 11,440 records. The numeric values of leaf N and P stoichiometry varied significantly across families and showed diverse trends along gradients of mean annual temperature(MAT) and mean annual precipitation(MAP). The leaf N and P concentrations and N:P ratios of 62 families ranged from 6.11 to 30.30 mg g–1, 0.27 to 2.17 mg g–1, and 10.20 to 35.40, respectively. Approximately 1/3–1/2 of the families(22–35 of 62) showed a decrease in leaf N and P concentrations and N:P ratios with increasing MAT or MAP, while the remainder either did not show a significant trend or presented the opposite pattern. Family-specific leaf N^P scaling exponents did not converge to a certain empirical value, with a range of 0.307–0.991 for 54 out of 62 families which indicated a significant N^P scaling relationship. Our results for the first time revealed large variation in the family-level leaf N and P stoichiometry of global terrestrial plants and that the stoichiometric relationships for at least one-third of the families were not consistent with the global trends reported previously. The numeric values of the family-specific leaf N and P stoichiometry documented in the current study provide critical synthetic parameters for biogeographic modeling and for further stud

关键词： leaf nitrogen (N) leaf phosphorus (P) plant stoichiometry family N:P ratios N^P scaling relationship climate

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Multi-scale phylogenetic structure in coastal dune plant communities across the globe

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Journal of Plant Ecology 2014年第2期7卷 101-114页

作者： Ane Kirstine Brunbjerg Jeannine Cavender-Bares Wolf L.Eiserhardt Rasmus Ejrnæs Lonnie W.Aarssen Hannah L.Buckley Estelle Forey Florian Jansen jens kattge Cynthia Lane Roy A.Lubke Angela T.Moles Ana Laura Monserrat Robert K.Peet Julissa Roncal Louise Wootton jens-Christian Svenning Ecoinformatics&Biodiversity Group Department of BioscienceAarhus UniversityNy Munkegade 114DK-8000 Aarhus C.Denmark Department of Bioscience Aarhus UniversityGrenaavej 14DK-8410 RøndeDenmark Department of Ecology Evolution and BehaviorUniversity of Minnesota1987 Upper Buford CircleFalcon HeightsMN 55108USA Department of Biology Queens University116 Barrie StreetKingstonOntario K7L 3N6Canada Department of Ecology Lincoln UniversityPO Box 84Canterbury 7647New Zealand Laboratoire d’Ecologie EA 1293 ECODIVFED SCALEUFR Sciences et TechniquesUniversitéde Rouen76821 Mont Saint Aignan CedexFrance Institute of Botany and Landscape Ecology Soldmannstr.1517487 GreifswaldGermany Functional Biogeography Research Group Max Planck Institute for BiogeochemistryHans Knoell Str.1007745 JenaThuringiaGermany Lake Lily Ecology Ltd.PO Box 8455CanmoreAB T1W 2V2Canada Department of Botany Rhodes UniversityPO Box 94GrahamstownEast Cape 6140South Africa Evolution&Ecology Research Centre School of BiologicalEarth and Environmental SciencesThe University of New South WalesBotany RoadKensingtonSydneyNew South Wales 2034Australia Grupo de Investigación en Sistemas Ambientales Complejos Facultad de IngenieríaUniversidad de FloresPedernera 275Ciudad de Buenos AiresArgentina Department of Biology University of North CarolinaChapel HillNC 27599-3280USA Department of Biology Memorial University of Newfoundland232 Elizabeth AvenueSt.John'sNL A1B 3X9Canada Department of Biology Georgian Court University900 Lakewood AvenueLakewoodNJ 08701USA

Aims Studies integrating phylogenetic history and large-scale community assembly are few,and many questions remain ***,we use a global coastal dune plant data set to uncover the important factors in community assembly across scales from the local filtering processes to the global long-term diversification and dispersal *** dune plant communities occur worldwide under a wide range of climatic and geologic conditions as well as in all biogeographic ***,global patterns in the phylogenetic composition of coastal dune plant communities have not previously been *** The data set comprised vegetation data from 18463 plots in New Zealand,South Africa,South America,North America and *** phylogenetic tree comprised 2241 plant species from 149 *** calculated phylogenetic clustering(Net Relatedness Index,NRI,and Nearest Taxon Index,NTI)of regional dune floras to estimate the amount of in situ diversification relative to the global dune species pool and evaluated the relative importance of land and climate barriers for these diversification patterns by geographic analyses of phylogenetic *** then tested whether dune plant communities exhibit similar patterns of phylogenetic structure within ***,we calculated NRI for local communities relative to the regional species pool and tested for an association with functional traits(plant height and seed mass)thought to vary along sea–inland *** Findings Regional species pools were phylogenetically clustered relative to the global pool,indicating regional *** showed stronger clustering than NRI pointing to the importance of especially recent diversifications within *** species pools grouped phylogenetically into two clusters on either side of the tropics suggesting greater dispersal rates within hemispheres than between *** NRI plot values confirmed that most communities were also phylogenetically clus

关键词： disturbance phylogenetic community structure plant functional traits plant height seed mass

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Systematic review of centrifugal valving based on digital twin modeling towards highly integrated lab-on-a-disc systems

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Microsystems & Nanoengineering 2021年第6期7卷 45-70页

作者： jens Ducrée School of Physical Sciences Dublin City UniversityDublinIreland

Current,application-driven trends towards larger-scale integration(LSI)of microfluidic systems for comprehensive assay automation and multiplexing pose significant technological and economical challenges to *** virtue of their intrinsic capability for powerful sample preparation,centrifugal systems have attracted significant interest in academia and business since the early *** review models common,rotationally controlled valving schemes at the heart of such“Lab-on-a-Disc”(LoaD)platforms to predict critical spin rates and reliability of flow control which mainly depend on geometries,location and liquid volumes to be processed,and their experimental *** absence of larger-scale manufacturing facilities during product development,the method presented here facilitates efficient simulation tools for virtual prototyping and characterization and algorithmic design optimization according to key performance *** virtual in silico approach thus significantly accelerates,de-risks and lowers costs along the critical advancement from idea,layout,fluidic testing,bioanalytical validation,and scale-up to commercial mass manufacture.

关键词： centrifugal advancement modeling

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Impact of the spindle number on the material transport and mixing during planetary roller melt granulation Author links open overlay panel

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Particuology 2024年第8期91卷 260-267页

作者： Tom Lang jens Bartsch Laboratory of Solids Process Engineering Department of Biochemical and Chemical EngineeringTU Dortmund University44227DortmundGermany

In comparison to the established twin-screw machines,the application of a planetary roller granulator for continuous operation of melt granulation is a promising alternative based on the unique process *** initial study focused on the material transport during processing as a key driver for the overall ***,the impact of direct process parameters on the residence time distribution was the main *** investigations are complemented in this study by considering the free processing volume,which is defined by the number of planetary spindles applied within a *** impact on the processing conditions is evaluated with respect to the process setting in terms of feed rate and rotation *** results highlight the potential of altering the underlying transport function in planetary roller melt granulation(PRMG)via the investigated direct process and equipment *** impact of the feed rate is lower in comparison,while a higher rotation speed as well as a higher free processing volume promote material ***,a normalization of the determined residence time distribution(RTD)model data was feasible with respect to the process settings and the number of applied planetary spindles in the processing *** demonstrates the key role of the free processing volume in the fundamental mechanisms of material transport and mixing during PRMG.

关键词： Continuous manufacturing Melt granulation Planetaryroller granulator Quality-by-Design Residence time Material mixing

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Nash and Stackelberg Differential Games

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Chinese Annals of Mathematics,Series B 2012年第3期33卷 317-332页

作者： Alain BENSOUSSAN jens FREHSE jens VOGELGESANG International Center for Decision and Risk Analysis School of ManagementUniversity of Texas-Dallas800 West Camptell RdSM30RichardsonTX 75050-3021USA Faculty of Business The Hong Kong Polytechnic University Department of Mathematics Institute of Applied MathematicsUniversity of BonnGermany PACM Princeton UniversityUSA HCM University of BonnGermany

A large class of stochastic differential games for several players is considered in this *** class includes Nash differential games as well as Stackelberg differential games.A mix is *** existence of feedback strategies under general conditions is *** limitations concern the functionals in which the state and the controls appear *** is also true for the state *** controls appear in a quadratic form for the payoff and linearly in the state *** most serious restriction is the dimension of the state equation,which cannot exceed *** reason comes from PDE(partial differential equations) techniques used in studying the system of Bellman equations obtained by Dynamic Programming *** the authors' previous work in 2002,there is not such a restriction,but there are serious restrictions on the structure of the Hamiltonians,which are violated in the applications dealt with in this article.

关键词： Stochastic games Bellman equation Nonlinear elliptic and parabolicequations Stochastic differential games Hamiltonians

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Development of fungal cell factories for the production of secondary metabolites:Linking genomics and metabolism

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Synthetic and Systems Biotechnology 2017年第1期2卷 5-12页

作者： jens Christian Nielsen jens Nielsen Chalmers University of Technology Kemivagen 10Sweden

The genomic era has revolutionized research on secondary metabolites and bioinformatics methods have in recent years revived the antibiotic discovery process after decades with only few new active molecules being *** computational tools are driven by genomics and metabolomics analysis,and enables rapid identification of novel secondary *** translate this increased discovery rate into industrial exploitation,it is necessary to integrate secondary metabolite pathways in the metabolic engineering *** this review,we will describe the novel advances in discovery of secondary metabolites produced by filamentous fungi,highlight the utilization of genome-scale metabolic models(GEMs)in the design of fungal cell factories for the production of secondary metabolites and review strategies for optimizing secondary metabolite production through the construction of high yielding platform cell factories.

关键词： Secondary metabolism Fungi Biosynthetic gene clusters Genome mining Metabolic modeling Cell factories

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Automatic route planning for GPS art generation

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Computational Visual Media 2019年第3期5卷 303-310页

作者： Andre Waschk jens Krüger University of Duisburg-Essen

In this paper, we present a novel approach to automated route generation of global positioning system(GPS) artwork. The term GPS artwork describes the generation of drawings by leaving virtual traces on digital maps. Until now, the creation of these images has required a manual planning phase in which an artist designs the route by hand. Once the route for this artwork has been planned, GPS devices have been used to track the movement. Using our solution, the lengthy planning phase can be significantly shortened,thereby opening art creation to a broader public.

关键词： GPS art walking routing shape detection navigation

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Chaotic ray dynamics enables photonics with broadband light

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Science China(Physics,Mechanics & Astronomy) 2018年第1期61卷 78-79页

作者： Hailin Wang jens Nockel Department of Physics University of Oregon Eugene OR 97403 USA

Propagation of sound waves through reflections along a curved surface was first theoretically analyzed by Lord Rayleigh to explain the whispering gallery waves in St. Paul＇s Cathedral in London. Similar whispering gallery sound waves are now a popular tourist attraction at the Echo Wall of the Temple of Heaven in Beijing. Whispering gallery phenomena also exist for light waves in dielectric spheres, disks, or toroids where total internal reflection allows the light to circulate with little attenuation and interfere with itself to form optical resonances or modes. These ＂whisper- ing gallery modes＂ have found applications ranging from photonics, quantum physics, biosensing, to optical clocks [1,2].

关键词： Chaotic ray dynamics enables photonics broadband light

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Response of small rodents to manipulations of vegetation height in agro-ecosystems

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Integrative Zoology 2008年第1期3卷 3-10页

作者： jens JACOB Federal Research Centre for Cultivated Plants-Julius Kuehn Institute Vertebrate ResearchMünsterGermany

Some small mammal populations require human interference to conserve rare or threatened species or to minimizeadverse effects in plant production. Without a thorough understanding about how small rodents behave in theirenvironment and consideration of how they react to management efforts, management will not be optimal. Socialbehavior, spatial and temporal activity patterns, predator avoidance and other behavioral responses can affect pestrodent management. Some of these behavioral patterns and their causes have been well studied. However, theirimpact on pest rodent management, especially for novel management approaches, is not always clear. Habitatmanipulation occurs necessarily through land use and intentionally to reduce shelter and food availability and toincrease predation pressure on rodents. Rodents often respond to decreased vegetation height with reducedmovements and increased risk sensitivity in their feeding behavior. This seems to result mainly from an elevatedperceived predation risk. Behavioral responses may lessen the efficacy of the management because the desiredeffects of predators might be mediated. It remains largely unknown to what extent such responses can compensateat the population level for the expected consequences of habitat manipulation and how population size and cropdamage are affected. It is advantageous to understand how target and non-target species react to habitatmanipulation to maximize the management effects by appropriate techniques, timing and spatial scale withoutcausing unwanted effects at the system level.

关键词： behavior crop protection pest rodent population dynamics vegetation height

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