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Soil water content and nitrogen differentially correlate with multidimensional leaf traits of two temperate broadleaf species

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Plant Diversity 2023年第6期45卷 694-701页

作者： Ming-Yue jin Daniel j.johnson Guang-Ze jin Qing-Xi Guo Zhi-Li Liu Center for Ecological Research Key Laboratory of Sustainable ForestEcosystem Management-Ministry of EducationNortheast Asia Biodiversity Research CenterNortheast Forestry UniversityHarbin 150040HeilongjiangChina School of Forest Resources and Conservation University of FloridaGainesvilleFLUSA

The variation and correlation of leaf economics and vein traits are crucial for predicting plant ecological strategies under different environmental ***,correlations between these two suites of traits and abiotic factors such as soil water and nitrogen content remain *** measured leaf economics and vein traits as well as soil water and nitrogen content for two different shade-tolerant species(Betula platyphylla and Acer mono)in four mixed broadleaved-Korean pine(Pinus koraiensis)forests along a latitudinal gradient in Northeast *** found that leaf economics traits and vein traits were decoupled in shade-intolerant species,Betula platphylla,but significantly coupled in a shadetolerant species,*** found stronger correlations among leaf traits in the shade tolerant species than in the shade intolerant ***,leaf economic traits were positively correlated with the soil water gradient for both species,whereas vein traits were positively correlated with soil water gradient for the shade intolerant species but negatively correlated in the shade tolerant *** economic traits were positively correlated with soil nitrogen gradient in shade intolerant species but not correlated in shade tolerant species,vein traits were negatively correlated with soil nitrogen gradient in shade tolerant species but not correlated in shade intolerant *** study provides evidence for distinct correlations between leaf economics and vein traits and local abiotic factors of species differing in light *** recommend that the ecological significance of shade tolerance be considered for species when evaluating ecosystem functions and predicting plant responses to environmental changes.

关键词： Leaf trait multidimensionality Economics traits Vein traits Soil water content Soil total nitrogen Shade tolerance

Density dependence and habitat preference shape seedling survival in a subtropical forest in central China

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journal of Plant Ecology 2015年第6期8卷 568-577页

作者： junmeng Lu Daniel j.johnson Xiujuan Qiao Zhijun Lu Qinggang Wang Mingxi jiang Key Laboratory of Aquatic Botany and Watershed Ecology Wuhan Botanical GardenChinese Academy of Sciences1 Moshan RoadWuhanHubei 430074China Department of Life Science University of Chinese Academy of Sciences19A YuQuan RoadBeijing 100049China School of Forestry and Environmental Studies Yale University195 Prospect StreetNew HavenCT 06511USA

Aims seedlings are vulnerable to many kinds of fatal abiotic and biotic agents,and examining the causes of seedling dynamics can help understand mechanisms of species *** disentangle the relative importance of neighborhood densities,habitat factors and phylogenetic relatedness on focal seedling survival,we monitored the survival of 5306 seedlings of 104 species>15 *** address the following questions:(i)How do neighborhood densities,habitat variables and phylogenetic relatedness affect seedling survival?What is the relative importance of conspecific densities,habitat variables and phylogenetic relatedness to seedling survival?(ii)Does the importance of the neighborhood densities,habitat variables and phylogenetic relatedness vary among growth forms,leaf habits or dispersal modes?specially,does the conspecific negative density dependence inhibit tree and decidu-ous seedlings more compared with shrub and evergreen species?Does density dependence affect the wind and animal-dispersed species equally?Methods We established 135 census stations to monitor seedling dynamics in a 25-ha subtropical forest plot in central *** and heterospecific seedling density in the 1-m2 seedling plot and adult basal area within a 20-m radius provided neighborhood density *** elevation,convexity and aspect of every 5-×5-m grid with seedling plots were used to quantify habitat *** calculated the relative average phylodiversity between focal seed-ling and heterospecific neighbors to quantify the species related-ness in the *** candidate generalized linear mixed models with binominal error distribution were used to compare the relative importance of these variables to seedling ***’s information criteria were used to identify the most parsimonious *** Findingsat the community level,both the neighborhood densities and phylogenetic relatedness were important to seedling *** found negative effec

关键词： generalized linear mixed models negative density dependence niche partitioning phylodiversity seedling dynamics species coexistence

Trees species’ dispersal mode and habitat heterogeneity shape negative density dependence in a temperate forest

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Forest Ecosystems 2023年第5期10卷 589-596页

作者： Lishunan Yang Daniel j.johnson Zhichun Yang Xiaochao Yang Qiulong Yin Ying Luo Zhanqing Hao Shihong jia School of Ecology and Environment Northwestern Polytechnical UniversityXi’anShaanxi710072China Shaanxi Key Laboratory of Qinling Ecological Intelligent Monitoring and Protection Northwestern Polytechnical UniversityXi’anShaanxi710072China School of Forest Fisheriesand Geomatics SciencesUniversity of FloridaGainesvilleFLUSA School of Geography and Tourism Shaanxi Normal UniversityXi’anShaanxi710062China

Conspecific negative density dependence(CNDD)is a potentially important mechanism in maintaining species *** previous evidence showed habitat heterogeneity and species’dispersal modes affect the strength of CNDD at early life stages of trees(e.g.,seedlings),it remains unclear how they affect the strength of CNDD at later life *** examined the degree of spatial aggregation between saplings and trees for species dispersed by wind and gravity in four topographic habitats within a 25-ha temperate forest dynamic plot in the Qinling Mountains of central *** used the replicated spatial point pattern(RSPP)analysis and bivariate paircorrelation function(PCF)to detect the spatial distribution of saplings around trees at two scales,15 and 50 m,*** the signal was not apparent across the whole study region(or 25-ha),it is distinct on isolated areas with specific characteristics,suggesting that these characteristics could be important factors in ***,we found that the gravity-dispersed tree species experienced CNDD across habitats,while for wind-dispersed species CNDD was found in gully,terrace and low-ridge *** study suggests that neglecting the habitat heterogeneity and dispersal mode can distort the signal of CNDD and community assembly in temperate forests.

关键词： Biodiversity Conspecific negative density dependence Dispersal Replicated point patterns Temperate forest Topographic habitat

Convergence of the turkey gut microbiota following cohabitation under commercial settings

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journal of Animal Science and Biotechnology 2021年第4期12卷 1635-1644页

作者： Elizabeth A.Miller Brittanie Winfield Bonnie P.Weber Cristian Flores-Figueroa jeannette Munoz-Aguayo jared Huisinga Timothy j.johnson Department of Veterinary and Biomedical Sciences University of MinnesotaSaint PaulMNUSA University of Minnesota Mid-Central Research and Outreach CenterWillmarMNUSA Science Innovations WillmarMNUSA

Background:Microbiota development is a critical aspect of turkey poult maturation,and the succession of microbes in the turkey gut has been shown to correlate with poult *** purpose of this study was to determine the fate of the microbiota in turkey poults after movement of birds first raised in an isolated hatch brood system into a more traditional commercial brood facility with pre-existing *** poults were first divided into groups raised in conventional brood pens from day-of-hatch and those raised in an experimental hatch brood *** 11 days of growth,hatch brood birds were moved into pens within the conventional brood barn and monitored for an additional 18 *** of both hatch brood and conventional pen birds was performed at multiple timepoints throughout the study,and cecal content was used to analyze the bacterial microbiota using 16S rRNA gene amplicon ***:Alpha diversity tended to be higher in samples from conventional pen birds compared to those from hatch brood birds prior to the day 11 move,but the difference between systems was not observed *** beta diversity metrics,bacterial community succession appeared delayed in the hatch brood system birds pre-move,but post-move community composition quickly converged with that of the conventional pen *** was validated through assessment of significantly different genera between hatch brood system and conventional pen birds,where numbers of significantly different taxa quickly decreased following the *** key taxa previously associated with poult performance were delayed in their appearance and relative abundance in hatch brood ***:Overall,this study demonstrates that the use of isolated hatch brood systems has an impact on the poult gut microbiota,but its impact is resolved quickly once the birds are introduced into a conventional brood ***,the benefits of pathogen reduction with hatch brood systems may out

关键词： Brood Gut Hatch Microbiota Poult Succession Turkey

Thrombogenicity of biodegradable metals

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Bioactive Materials 2024年第8期38卷 411-421页

作者： D.E.j.Anderson H.H.Le H.Vu j.johnson j.E.Aslan j.Goldman M.T.Hinds Department of Biomedical Engineering Oregon Health&Science UniversityPortlandORUSA Knight Cardiovascular Institute Oregon Health&Science UniversityPortlandORUSA Department of Biomedical Engineering Michigan Technological UniversityHoughtonMIUSA

Biodegradable metals offer a promising means to ameliorate many of the long-term risks associated with vascular devices made of conventional biostable stent *** numerous biodegradable metal alloys have been developed and characterized in animal models,knowledge of their blood reactivity and thrombogenicity remains *** hemocompatibility is particularly valuable because current generation drug-eluting stents pose a significant long-term thrombosis *** this study,four pure metals,widely used as degradable base materials(Fe,Zn,Mg,and Mo),and three alloys commonly used in cardiovascular devices[NiTi,CoCr,and stainless steel(SS)]were *** work examined how each of these metals activate platelets,coagulation factors,and inflammation using in vitro hemocompatibility assays and a clinically relevant ex vivo non-human primate arteriovenous shunt *** found that while all metals promoted a downstream activation of platelets and coagulation in flowing whole blood,platelet and fibrin attachment to Mg was markedly ***,Fe and Mo trended toward higher platelet attachment and contact pathway ***,the results suggest that Mg may delay clot initiation,but not eliminate clot formation,indicating the importance of understanding thrombosis in Mg alloys that are currently being developed for clinical use as biodegradable stents.

关键词： Vascular stents Biodegradable metals Thrombosis Contact pathway Platelets

Multiple Access Technologies for Cellular M2M Communications

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ZTE Communications 2016年第4期14卷 42-49页

作者： Mahyar Shirvanimoghaddam Sarah j.johnson School of Electrical Engineering and Computer Science The University of Newcastle

This paper reviews the multiple access techniques for machine-to-machine(M2M) communications in future wireless cellular networks. M2M communications aims at providing the communication infrastructure for the emerging Internet of Things(IoT), which will revolutionize the way we interact with our surrounding physical environment. We provide an overview of the multiple access strategies and explain their limitations when used for M2M communications. We show the throughput efficiency of different multiple access techniques when used in coordinated and uncoordinated scenarios. Non-orthogonal multiple access(NOMA) is also shown to support a larger number of devices compared to orthogonal multiple access techniques, especially in uncoordinated scenarios. We also detail the issues and challenges of different multiple access techniques to be used for M2M applications in cellular networks.

关键词： Internet of Things(IoT) massive access machine-to-machine(M2M) communications multiple access

IMPORTANCE OF HYDROLOGY, SOIL AND VEGETATIONIN WETLAND RESEARCH

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湿地科学 2003年第2期1卷 128-135页

作者： Elizabeth j.johnson Peter L.M.Veneman XING Baos-han Dept. of Plant and Soil Science Univ. of Massachusetts Amherst MA 01003 USADept. of Plant and Soil Science Univ. of Massachusetts Amherst MA 01003 USANortheast Institute of Geography and Agro-ecology CASHarbin 150040P R China Dept. of Plant and Soil Science Univ. of Massachusetts Amherst MA01003USA

Wetlands, one of the most productive systems in the biosphere are a unique ecosystem. They occur in landscapes that favor the ponding or slow runoff of surface water, discharge of ground water, or both. Wetlands are not only important for maintaining plant and animal diversity, but also for balancing global carbon budget via sequestrating or releasing CO2 from/into atmosphere depending on their management. Therefore, it is imperative to understand how wetlands form and function, then we can better manage, utilize, and protect these unique ecosystems. Hydrie soils,hydrophytic vegetation, and wetland hydrology are the three main parameters of wetlands. These parameters are interrelated with each other which jointly influence the development and functions of wetland ecosystems. The objective of this paper was to report the current understanding of wetlands and provide future research directions. The paper will first focus on aspects of hydrology research in wetlands, and then shift to soil hydrosequence and wetland vegetation to better understand processes, structure, and function of wetlands, and conclude with some possible future research directions.

关键词： hydric soils vegetation hydrology wetlands future research

Piglet gut microbial shifts early in life:causes and effects

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journal of Animal Science and Biotechnology 2019年第3期10卷 519-528页

作者： Robin B.Guevarra jun Hyung Lee Sun Hee Lee Min-jae Seok Doo Wan Kim Bit Na Kang Timothy j.johnson Richard E.Isaacson Hyeun Bum Kim Department of Animal Resources Science Dankook UniversityCheonan 31116South Korea National Institute of Animal Science Rural Development AdministrationCheonan 55365South Korea Abbvie Bioresearch Center AbbvieWorcesterMA 01605USA Department of Veterinary and Biomedical Sciences University of MinnesotaSt.PaulMN 55108USA

The gut microbiome has long been known to play fundamentally important roles in the animal health and the well-being of its host. As such, the establishment and maintenance of a beneficial gut microbiota early in life is crucial in pigs, since early gut colonizers are pivotal in the establishment of permanent microbial community structures affecting the health and growth performance of pigs later in life. Emphasizing this importance of early gut colonizers, it is critical to understand the factors impacting the establishment of the piglet gut microbiome at weaning. Factors include, among others, diet, in-feed antibiotics, probiotics and prebiotic administration. The impact of these factors on establishment of the gut microbiome of piglets at weaning includes effects on piglet gut microbial diversity, structure, and succession. In this review, we thoroughly reviewed the most recent findings on the piglet gut microbiome shifts as influenced by weaning, and how these microbiome changes brought about by various factors that have been shown to affect the development of microbiota in piglets. This review will provide a general overview of recent studies that can help to facilitate the design of new strategies to modulate the gut microbiome in order to enhance gastrointestinal health, growth performance and well-being of piglets.

关键词： Microbial diversity Next generation sequencing 16S rRNA Swine microbiota Weaning

Advances in Y-90 radioembolization for the treatment of hepatocellular carcinoma

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Hepatoma Research 2022年第1期8卷 9-21页

作者： andrew j.Woerner Guy E.johnson Department of Radiology Section of Interventional RadiologyUniversity of WashingtonSeattleWA 98195USA

Hepatocellular carcinoma remains a prominent cause of cancer-related mortality *** yttrium-90 radioembolization is a versatile therapy and plays an important role in the treatment of hepatocellular *** review summarizes the establishment of radioembolization in the hepatocellular carcinoma treatment paradigm,treatment considerations across cancer stages,and recent advances in evidence.

关键词： Hepatocellular carcinoma radioembolization yttrium-90 dosimetry radiation segmentectomy