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Differential effects of two dominant plant species on community structure and invasibility in an old-field ecosystem

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journal of Plant Ecology 2011年第3期4卷 123-131页

作者： Lara Souza jake F.Weltzin Nathan J.Sanders Department of Ecology and Evolutionary Biology University of Tennessee1416 Circle DriveKnoxvilleTN 37996USA USA National Phenology Network National Coordinating Office1955 East 6th StreetTucsonAZ 85719USA

Aims In this study,we examined the effects of Solidago altissima(hereafter Solidago)and two species in the genus Verbesina,Verbesina virginica and Verbesina occidentalis(hereafter Verbesina),on the structure of an old-field plant community and establishment by an invasive plant species,Lespedeza cuneata(hereafter Lespedeza).Methods We removed Solidago,Verbesina and both Solidago and Verbesina from 4m^(-2)plots in an intact old-field community during two growing seasons.We then quantified the effects of these removals on richness,evenness,diversity and composition of the subdominant plant community.We also measured the total aboveground biomass and the aboveground biomass of the subdominant community.To assess how these removals affected establishment by Lespedeza,we planted 20 seeds in each plot and tracked seedling emergence and survival for one growing season.Important Findings Subdominant community evenness and Shannon diversity were higher in plots from which Solidago and Verbesina were removed relative to control plots.However,there were no effects of dominant species removal on species richness or composition of the subdominant community.Total aboveground biomass was not affected by dominant species removal,suggesting that the community of subdominant species exhibited compensation.In fact,subdominant community biomass was greater when Solidago,but not Verbesina,was removed.Light availability was also greater in plots where Solidago was removed relative to control plots throughout the growing season.In addition,removal of dominant species,in particular Solidago,indirectly reduced the emergence,but not survival,of Lespedeza seedlings by directly promoting subdominant community biomass.Taken together,our results suggest that dominant old-field plant species affect subdominant community structure and indirectly promote establishment by Lespedeza.

关键词： compensation establishment invasive Lespedeza cuneata Solidago Verbesina

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Aboveground resilience to species loss but belowground resistance to nitrogen addition in a montane plant community

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journal of Plant Ecology 2018年第3期11卷 351-363页

作者： Quentin D.Read jeremiah A.Henning Aimée T.Classen Nathan J.Sanders Department of Ecology and Evolutionary Biology University of Tennessee569 Dabney HallKnoxvilleTN 37996USA Rocky Mountain Biological Laboratory PO Box 615Crested ButteCO 81224USA Center for Macroecology Evolutionand ClimateNatural History Museum of DenmarkUniversity of CopenhagenUniversitetsparken 152100 CopenhagenDenmark Rubenstein School of Environment and Natural Resources University of VermontBurlingtonVT 05405USA

Aims Decades of empirical work have demonstrated how dominant plant species and nitrogen fertilization can influence the structure and function of plant communities.More recent studies have examined the interplay between these factors,but few such studies use an explicit trait-based framework.In this study,we use an explicit trait-based approach to identify potential mechanisms for community-level responses and to test ecological niche theory.Methods We experimentally manipulated plant communities(control,−dom-inant species,−random biomass)and nitrogen(N)inputs(control,+organic N,+inorganic N)in a fully factorial design.We predicted that traits related to plants’ability to take up different forms of soil N would differ between dominant and subordinate species,resulting in interactive effects of dominant species loss and N fertilization on plant community structure and function.The study took place in a montane meadow in the Rocky Mountains,Colorado,USA.Important Findings After four years,the plant community in removal plots converged toward a species composition whose leaf and root functional traits resembled those of the previously removed dominant species.Ecosystem productivity generally increased with N addition:soil carbon efflux was~50%greater when either form of N was added,while inorganic N addition increased aboveground biomass pro-duction by~60%relative to controls.The increase in production was mediated by increased average height,leaf mass:area ratio and leaf dry matter content in plant communities to which we added inorganic N.Contrary to our predictions,there were no interactive effects of N fertilization and dominant species loss on plant com-munity structure or ecosystem function.The plant community com-position in this study exhibited resistance to soil N addition and,given the functional convergence we observed,was resilient to spe-cies loss.Together,our results indicate that the ability of species to compensate functionally for species loss confers resilience and maintains diversity in montane m

关键词： dominant species fertilization functional trait removal experiment resilience

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Variation in the methods leads to variation in the interpretation of biodiversity-ecosystem multifunctionality relationships

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journal of Plant Ecology 2020年第4期13卷 431-441页

作者： Xin jing Case M.Prager Aimée T.Classen Fernando T.Maestre jin-Sheng He Nathan J.Sanders Rubenstein School of Environment and Natural Resources University of VermontBurlingtonVT 05405USA Gund Institute for Environment University of VermontBurlingtonVT 05405USA Center for Macroecology Evolutionand ClimateNatural History Museum of DenmarkCopenhagenDenmark Departamento de Biología GeologíaFísica y Química InorgánicaEscuela Superior de Ciencias Experimentales y TecnologíaUniversidad Rey Juan CarlosMóstoles 28933Spain Departamento de Ecología and Instituto Multidisciplinar para el Estudio del Medio“Ramon Margalef” Universidad de AlicanteAlicanteSpain Department of Ecology College of Urban and Environmental SciencesPeking UniversityBeijingChina Environmental Program Rubenstein School of Environment and Natural ResourcesUniversity of VermontBurlingtonVT 05405USA Present address:Department of Earth and Environmental Sciences KU LeuvenCelestijnenlaan 200E3001 LeuvenBelgium

生物多样性常常和生态系统多功能性(生态系统同时提供多个生态系统功能的能力)正相关。然而,生物多样性与生态系统多功能性的关系是否依赖于生态系统功能的数目有诸多争议。其中,生物多样性对生态系统多功能性的影响或许不随生态系统功... 详细信息

生物多样性常常和生态系统多功能性(生态系统同时提供多个生态系统功能的能力)正相关。然而,生物多样性与生态系统多功能性的关系是否依赖于生态系统功能的数目有诸多争议。其中,生物多样性对生态系统多功能性的影响或许不随生态系统功能数目的变化而变化,或者随生态系统功能数目的增多而增强。我们期望通过研究不同生态系统多功能性指数的统计原理来解决这些争议。我们使用了模型模拟和一系列来自不同空间尺度(从局域到全球)和不同生物群系(温带和高寒草地、森林和干旱地)的经验数据。我们回顾了量化生态系统多功能性的三种方法,包括平均值法、加和法和阈值法。我们发现随着生态系统功能数目的增加,生物多样性与生态系统多功能性的关系要么不变,要么增强。这些结果可由平均和加和的多功能性指数的统计原理来解释。具体来讲,当利用生态系统功能的平均值计算多功能性指数时,由于多样性对多功能性的效应等于多样性对单个生态系统功能效应的平均值,所以不会随生态系统功能数目的变化而变化。同样的道理,当利用单个生态系统的加和值计算多功能性指数时,多样性的效应会随着生态系统功能数目的增加而增强。我们提出了一个改进的多功能性指数,将平均或加和多功能性指数转化为标准化的多功能性指数,以便于对不同研究的结果进行比较。此外,我们提出了基于变量数值范围的标准化方法来解决阈值法的数学假象问题(多样性效应随生态系统功能数目的增加而增强)。我们的研究结果表明,量化多功能性指数的方法不同,结果也不同。因此,有必要加深对不同方法数理基础的理解。而标准化的多功能性指数为比较不同研究中的生物多样性与生态系统多功能性的关系提供了有效的方法。

关键词：平均值法生物多样性生态系统多功能性多阈值法植物物种丰富度空间尺度

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The parallel-plate resonator:An RF probe for MR and MRI studies over a wide frequency range

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Magnetic Resonance Letters 2023年第4期3卷 306-318页

作者： Andres Ramírez Aguilera Kevin j.sanders Gillian R.Goward Bruce *** UNB MRI Centre Department of PhysicsUniversity of New BrunswickFrederictonNew BrunswickE3B 5A3Canada Department of Chemistry McMaster UniversityHamiltonOntarioL8S 4L8Canada

We explore the use of the parallel-plate resonator for the study of thin cuboid samples over a wide range of magnetic resonance frequencies.The parallel-plate resonator functions at frequencies from tens to hundreds of MHz.Seven parallel-plate resonators are presented and discussed in a frequency range from 8 to 500 MHz.Magnetic resonance experiments were performed on both horizontal and vertical bore magnet systems with lithium and hydrogen nuclei.Parallel-plate radiofrequency(RF)probes are easy to build and easy to optimize.Experiments and simulations showed good sensitivity of the parallel-plate RF probe geometry with a small decrease in sensitivity at higher frequencies.

关键词： Parallel-plate resonator Optimization Magnetic resonance/magnetic resonance imaging(MR/MRI) Batteries

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Coastal blue carbon in China as a nature-based solution toward carbon neutrality

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The Innovation 2023年第5期4卷 109-123页

作者： Faming Wang jihua Liu Guoming Qin jingfan Zhang jinge Zhou jingtao Wu Lulu Zhang Poonam Thapa Christian j.sanders Isaac R.Santos Xiuzhen Li Guanghui Lin Qihao Weng jianwu Tang Nianzhi jiao Hai Ren Xiaoliang Research Station of Tropical Coastal Ecosystems Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystemsand the CAS Engineering Laboratory for Ecological Restoration of lsland and Coastal EcosystemsSouth China Botanical GardenChinese Academy of SciencesGuangzhou 510650China Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) Guangzhou 510650China Marine Research Institute Shandong UniversityQingdao 266237China University of Chinese Academy of Sciences Beijing 100049China National Marine Science Centre Faculty of Science and EngineeringSouther Cross UniversityCoffs HarbourNSW 2450Australia Department of Marine Sciences University of Gothenburg41319 GothenburgSweden State Key Laboratory of Estuarine and Coastal Research and Instiute of Eco-Chongming East China Normal UniversityShanghai 201100China Key Laboratory for Earth System Modeling Ministry of EducationDepartment of Earth System ScienceTsinghua UniversityBejing 100084China Laboratory of Stable Isotope and Gulf Ecology Institute of Ocean EngineeringTsinghua's Shenzhen International Graduate SchoolShenzhen 518055China Department of Land Surveying and Geo-nformatics The Hong Kong Polytechnic UniversiyHongkong 99077China Innovative Research Center for Carbon Neutralization Global ONCE ProgramXiamen 361005China

To achieve the Paris Agreement,China pledged to become“Carbon Neutral”by the 2060s.In addition to massive decarbonization,this would require significant changes in ecosystems toward negative CO_(2)emissions.The ability of coastal blue carbon ecosystems(BCEs),including mangrove,salt marsh,and seagrass meadows,to sequester large amounts of CO_(2)makes their conservation and restoration an important“nature-based solution(NbS)”for climate adaptation and mitigation.In this review,we examine how BCEs in China can contribute to climate mitigation.On the national scale,the BCEs in China store up to 118 Tg C across a total area of 1,440,377 ha,including over 75%as unvegetated tidal flats.The annual sedimental C burial of these BCEs reaches up to 2.06 Tg C year^(−1),of which most occurs in salt marshes and tidal flats.The lateral C flux of mangroves and salt marshes contributes to 1.17 Tg C year^(−1)along the Chinese coastline.Conservation and restoration of BCEs benefit climate change mitigation and provide other ecological services with a value of$32,000 ha^(−1)year^(−1).The potential practices and technologies that can be implemented in China to improve BCE C sequestration,including their constraints and feasibility,are also outlined.Future directions are suggested to improve blue carbon estimates on aerial extent,carbon stocks,sequestration,and mitigation potential.Restoring and preserving BCEs would be a cost-effective step to achieve Carbon Neutral by 2060 in China despite various barriers that should be removed.

关键词： tidal coastal carbon

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Multinuclear MR and MRI study of lithium-ion cells using a variable field magnet and a fixed frequency RF probe

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Magnetic Resonance Letters 2024年第1期4卷 10-20页

作者： Andrés Ramírez Aguilera Florin Marica Kevin j.sanders Md Al Raihan C.Adam Dyker Gillian R.Goward Bruce *** UNB MRI Centre Department of PhysicsUniversity of New BrunswickFrederictonNew BrunswickE3B 5A3Canada Department of Chemistry McMaster UniversityHamiltonOntarioL8S 4L8Canada Department of Chemistry University of New BrunswickFrederictonNew BrunswickE3B 5A3Canada

An exploratory multinuclear magnetic resonance(MR)and magnetic resonance imaging(MRI)study was performed on lithium-ion battery cells with ^(7)Li,^(19)F,and ^(1)H measurements.A variable field superconducting magnet with a fixed frequency parallel-plate radiofrequency(RF)probe was employed in the study.The magnetic field was changed to set the resonance frequency of each nucleus to the fixed RF probe frequency of 33.7 MHz.Two cartridge-like lithium-ion cells,with graphite anodes and LiNi_(0.5)Mn_(0.3)Co_(0.2)O_(2)(NMC)cathodes,were interrogated.One cell was pristine,and one was charged to a cell voltage of 4.2 V.The results presented demonstrate the great potential of the variable field magnet approach in multinuclear measurement of lithium-ion batteries.These methods open the door for developing faster and simpler methods for detecting,quantifying,and interpreting MR and MRI data from lithium-ion and other batteries.

关键词： Multinuclear MR/MRI Variable field magnet Lithium-ion battery Parallel-plate rf probe

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Global blue carbon accumulation in tidal wetlands increases with climate change

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National Science Review 2021年第9期8卷 145-155页

作者： Faming Wang Christian j.sanders Isaac R.Santos jianwu Tang Mark Schuerch Matthew L.Kirwan Robert E.Kopp Kai Zhu Xiuzhen Li jiacan Yuan Wenzhi Liu Zhian Li Department of Environmental Studies University of California Department of Atmospheric and Oceanic Sciences Fudan University CAS Key Laboratory of Aquatic Botany and Watershed Ecology Wuhan Botanical GardenChinese Academy of Sciences Xiaoliang Research Station for Tropical Coastal Ecosystems Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems and the CAS Engineering Laboratory for Ecological Restoration of Island and Coastal Ecosystems South China Botanical Garden Chinese Academy of Sciences Center of Plant Ecology Core Botanical Gardens Chinese Academy of Sciences Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) State Key Laboratory of Estuarine and Coastal Research and Institute of Eco-Chongming East China Normal University National Marine Science Centre School of Environment Science and Engineering Southern Cross University Department of Marine Sciences University of Gothenburg Lincoln Centre for Water and Planetary Health School of Geography University of Lincoln Virginia Institute of Marine Science College of William and Mary Department of Earth and Planetary Sciences and Rutgers Institute of Earth Ocean and Atmospheric Sciences Rutgers University

Coastal tidal wetlands produce and accumulate significant amounts of organic carbon(C) that help to mitigate climate change. However, previous data limitations have prevented a robust evaluation of the global rates and mechanisms driving C accumulation. Here, we go beyond recent soil C stock estimates to reveal global tidal wetland C accumulation and predict changes under relative sea level rise, temperature and precipitation. We use data from literature study sites and our new observations spanning wide latitudinal gradients and 20 countries. Globally, tidal wetlands accumulate 53.65(95%CI: 48.52–59.01)Tg C yr-1, which is ～30% of the organic C buried on the ocean floor. Modeling based on current climatic drivers and under projected emissions scenarios revealed a net increase in the global C accumulation by2100. This rapid increase is driven by sea level rise in tidal marshes, and higher temperature and precipitation in mangroves. Countries with large areas of coastal wetlands, like Indonesia and Mexico, are more susceptible to tidal wetland C losses under climate change, while regions such as Australia, Brazil, the USA and China will experience a significant C accumulation increase under all projected scenarios.

关键词： coastal wetlands blue C C burial rate global change

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雷达元器件的新发展

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现代雷达 1990年第3期12卷 60-67页

作者： Robert j.sanders 陈能秋 ITT Gilfillan

正确选择结构形式,改进功率分配/合成网络,提高晶体管的功率电平和工作频率,指明了设计先进雷达发射机的方法。

关键词：雷达元器件接收机

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Use of donepezil for neurocognitive recovery after brain injury in adult and pediatric populations:a scoping review

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Neural Regeneration Research 2024年第8期19卷 1686-1695页

作者： Avery L.Miller nathan K.Evanson j.Michael Taylor University of Cincinnati College of Medicine CincinnatiOHUSA Department of Pediatrics University of CincinnatiCincinnatiOHUSA Department of Neurology and Rehabilitation Medicine University of CincinnatiCincinnatiOHUSA Division of Pediatric Rehabilitation Medicine Cincinnati Children’s Hospital Medical CenterCincinnatiOHUSA Division of Neurology Cincinnati Children’s Hospital Medical CenterCincinnatiOHUSA

There are few pharmacologic options for the treatment of cognitive deficits associated with traumatic brain injury in pediatric patients.Acetylcholinesterase inhibitors such as donepezil have been evaluated in adult patients after traumatic brain injury,but relatively less is known about the effect in pediatric populations.The goal of this review is to identify knowledge gaps in the efficacy and safety of acetylcholinesterase inhibito rs as a potential a djuvant treatment fo r neurocognitive decline in pediatric patients with traumatic brain injury.Investigators queried PubMed to identify literature published from database inception thro ugh june 2023 desc ribing the use of donepezil in young adult traumatic brain injury and pediatric patients with predefined conditions.Based on preselected search criteria,340 unique papers we re selected for title and abstra ct screening.Thirty-two reco rds were reviewed in full after eliminating preclinical studies and pape rs outside the scope of the project.In adult traumatic brain injury,we review results from 14 papers detailing 227 subjects where evidence suggests donepezil is well tole rated and shows both objective and patient-reported efficacy for reducing cognitive impairment.In children,3 pape rs report on 5 children recovering from traumatic brain injury,showing limited efficacy.An additional 15 pediatric studies conducted in populations at risk for cognitive dysfunction provide a broader look at safety and efficacy in 210 patients in the pediatric age group.Given its promise for efficacy in adults with traumatic brain injury and tole rability in pediatric patients,we believe further study of donepezil for children and adolescents with traumatic brain injury is warranted.

关键词： acetylcholinesterase inhibitor adult cognition donepezil pediatrics traumatic brain injury

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The skeletal muscle fiber periphery:A nexus of mTOR-related anabolism

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运动医学与健康科学(英文) 2023年第1期5卷 10-19页

作者： Cassidy T.Tinline-Goodfellow Matthew j.Lees nathan Hodson Faculty of Kinesiology and Physical Education University of TorontoCanada Institute of Sport Manchester Metropolitan UniversityManchesterUnited Kingdom Department of Sport and Exercise Sciences Manchester Metropolitan UniversityManchesterUnited Kingdom

Skeletal muscle anabolism is driven by numerous stimuli such as growth factors,nutrients(i.e.,amino acids,glucose),and mechanical stress.These stimuli are integrated by the mechanistic target of rapamycin(mTOR)complex 1(mTORC1)signal transduction cascade.In recent years,work from our laboratory and elsewhere has sought to unravel the molecular mechanisms underpinning the mTOR-related activation of muscle protein synthesis(MPS),as well as the spatial regulation of these mechanisms within the skeletal muscle cell.These studies have suggested that the skeletal muscle fiber periphery is a region of central importance in anabolism(i.e.,growth/MPS).Indeed,the fiber periphery is replete with the substrates,molecular machinery,and translational apparatus necessary to facilitate MPS.This review provides a summary of the mechanisms underpinning the mTOR-associated activation of MPS from cell,rodent,and human studies.It also presents an overview of the spatial regulation of mTORC1 in response to anabolic stimuli and outlines the factors that distinguish the periphery of the cell as a highly notable region of skeletal muscle for the induction of MPS.Future research should seek to further explore the nutrient-induced activation of mTORC1 at the periphery of skeletal muscle fibers.

关键词： Skeletal muscle mTOR Periphery Muscle protein synthesis Hypertrophy Translation

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