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Public health importance of light intensity physical activity

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Journal of sport and Health science 2024年第5期13卷 674-675页

作者： Robert Ross Ian Janssen mark.s.Tremblay school of Kinesiology and Health studies Queen’s UniversityKingstonON K7L 3N6Canada school of Medicine Division of Endocrinology and MetabolismQueen’s UniversityKingstonON K7L 3N6Canada Healthy Active Living and Obesity Research Group Children’s Hospital of Eastern Ontario Research InstituteOttawaON K1H 8L1Canada Department of Pediatrics University of OttawaOttawaON K1H 8L1Canada

*** intensity physical activity(PA)benefits health PA guidelines worldwide recommend that adults accumulate 150 min of moderate intensity or 75 min of vigorous intensity PA(moderate-to-vigorous PA(MVPA))weekly to achieve health benefits.1-3 Absent from these guidelines are recommendations for light intensity PA(LPA,e.g.,walking at a leisurely pace of 3 km/h or less,equivalent to 1.5-2.9 metabolic equivalents).

关键词： intensity light benefits

Old-growth mixed dipterocarp forests show variable losses and gains in aboveground biomass and standing carbon over forty years

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Forest Ecosystems 2024年第1期11卷 14-23页

作者： sisira Ediriweera Champika Bandara Tithira Lakkana shanika Jayasinghe David Woodbury Arun Dayanandan B.M.P.singhakumara Xiangcheng Mi I.A.U.N.Gunatilleke C.V.s.Gunatilleke mark.sAshton Department of science and Technology Uva Wellassa UniversityBadullaSri Lanka The Forest school Yale School of the EnvironmentYale UniversityNew HavenCT06511USA Department of Forestry and Environmental science University of Sri JayewardenepuraNugegodaSri Lanka state Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of SciencesBeijing100093China Botany Department University of PeradeniyaPeradeniyaSri Lanka

Background:No studies have documented long-term trends in aboveground biomass(AGB)for mixed-dipterocarp forests(MDF),the dominant rain forest type in tropical wet equatorial *** our study,we sought to document such trends over forty years across three sites representing lowland to lower montane ***:To do this,we established fifty 100 m×25 m plots in 1978 across three sites sampled along an elevation gradient,identified as mature old-growth *** measured trees for diameter at breast height that we identified to species and *** took wood samples to calculate species wood-specific *** re-measured plots in 1998 and again in ***:We show standing AGB for all sites combined to be 517.52 Mg·ha^(-1)in 1978,but this declined by 17%over 40 years to 430.11 Mg·ha^(-1).No differences exist among sites in AGB primarily because of considerable within site variation;but interactions of time with site show declines across sites were not uniform,one remained about the *** few species represented a high proportion of the AGB with the top five species comprising between 34%and 65%,depending upon site and year *** species,Mesua nagassarium,represented a disproportionately large amount of AGB and decline over time,particularly at the low elevation ***:Our results are directly relevant to estimating AGB and standing carbon sequestered in *** study is the first to demonstrate varying but overall,declining trends in amounts of AGB among forests making predictions of biomass and standing carbon in MDF difficult over wide regions.

关键词： Western ghats shorea spp. southeast Asia sri Lanka Tropical rain forest Wood specific gravity

Design Improvements and Validation of a Novel Fully 3D Printed Analogue Lumbar spine Motion segment

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Journal of Bionic Engineering 2024年第3期21卷 1388-1396页

作者： siril Teja Dukkipati mark Driscoll Musculoskeletal Biomechanics Research Lab Department of Mechanical EngineeringMcGill University845 Sherbrooke St.W(163)MontréalQCH3A 0C3Canada Orthopaedic Research Lab Montreal General Hospital1650 Cedar Ave(LS1.409)MontréalQCH3G 1A4Canada

spine biomechanical testing methods in the past few decades have not evolved beyond employing either cadaveric studies or finite element modeling ***,both these approaches may have inherent cost and time *** studies are the present gold standard for spinal implant design and regulatory approval,but they introduce significant variability in measurements across patients,often requiring large sample *** element modeling demands considerable expertise and can be computationally expensive when complex geometry and material nonlinearity are *** analogue spine models could complement these traditional methods as a low-cost and high-fidelity alternative.A fully 3D printable L-s1 analogue spine model with ligaments is developed and validated in this *** stiffness of the model under pure bending loading in flexion-extension,Lateral Bending(LB)and Axial Rotation(AR)is evaluated and compared against historical ex vivo and in silico ***,the effect of interspinous,intertransverse ligaments and the Thoracolumbar Fascia(TLF)on spinal stiffness is evaluated by systematic construction of the *** flexion,model Range of Motion(ROM)was 12.92±0.11°(ex vivo:16.58°,in silico:12.96°)at *** LB,average ROM was 13.67±0.12°at 7.5 Nm(ex vivo:15.21±1.89°,in silico:15.49±0.23°).similarly,in AR,average ROM was 17.69±2.12°at 7.5Nm(ex vivo:14.12±0.31°,in silico:15.91±0.28°).The addition of interspinous and intertransverse ligaments increased both flexion and LB stiffnesses by approximately 5%.Addition of TLF showed increase in flexion and AR stiffnesses by 29%and 24%,*** novel model can reproduce physiological ROMs with high repeatability and could be a useful open-source tool in spine biomechanics.

关键词： Lumbar spine 3D printing Intervertebral disc Biomechanical testing spine mechanics

Normal Crossings singularities for symplectic Topology:structures

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Acta Mathematica sinica,English series 2024年第1期40卷 107-160页

作者： Mohammad FARAJZADEH-TEHRANI mark MCLEAN Aleksey ZINGER The University of Iowa MacLean HallIowa CityIA 52241 Department of Mathematics Stony Brook UniversityStony BrookNY 11794

Our previous papers introduce topological notions of normal crossings symplectic divisor and variety,show that they are equivalent,in a suitable sense,to the corresponding geometric notions,and establish a topological smoothability criterion for normal crossings symplectic *** present paper constructs a blowup,a complex line bundle,and a logarithmic tangent bundle naturally associated with a normal crossings symplectic divisor and determines the Chern class of the last *** structures have applications in constructions and analysis of various moduli *** a corollary of the Chern class formula for the logarithmic tangent bundle,we refine Aluffi’s formula for the Chern class of the tangent bundle of the blowup at a complete intersection to account for the torsion and extend it to the blowup at the deepest stratum of an arbitrary normal crossings divisor.

关键词： Normal crossings divisor Chern class Logarithmic tangent bundle

Analysis of the inflection points of height-diameter models

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Forest Ecosystems 2024年第4期11卷 414-422页

作者： Tzeng Yih Lam mark J.Ducey Department of Forest Resources Management Faculty of ForestryThe University of British Columbia2045-2424 Main MallVancouverBCV6T 1Z4 Canada Department of Natural Resources and the Environment University of New Hampshire114 James HallDurhamNH 03824USA

The inflection point is an important feature of sigmoidal height-diameter(H-D)*** is often cited as one of the properties favoring sigmoidal model ***,there are very few studies analyzing the inflection points of H-D *** goals of this study were to theoretically and empirically examine the behaviors of inflection points of six common H-D models with a regional *** six models were the Wykoff(WYK),schumacher(sCH),Curtis(CUR),HossfeldⅣ(HOs),von Bertalanffy-Richards(VBR),and Gompertz(GPZ)*** models were first fitted in their base forms with tree species as random effects and were then expanded to include functional traits and spatial *** distributions of the estimated inflection points were similar between the two-parameter models WYK,sCH,and CUR,but were different between the threeparameter models HOs,VBR,and *** produced some of the largest inflection *** and VBR produced concave H-D curves without inflection points for 12.7%and 39.7%of the tree *** species or decreasing shade tolerance resulted in larger inflection *** trends in the estimated inflection points of HOs and VBR were entirely opposite across the ***,HOs could produce concave H-D curves for portions of the *** on the studied behaviors,the choice between two-parameter models may not *** recommend comparing seve ral three-parameter model forms for consistency in estimated inflection points before deciding on *** sigmoidal models to have inflection points does not necessarily mean that they will produce fitted curves with *** study highlights the need to integrate analysis of inflection points into modeling H-D relationships.

关键词： Concavity Forest inventory and analysis Generalized height-diameter models Growth functions Height-diameter functions Mixed-effects modeling Points of inflection species-specific models

Electroactivity of the magnetotactic bacteria Magnetospirillum magneticum AMB-1 and Magnetospirillum gryphiswaldense MsR-1

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Frontiers of Environmental science & Engineering 2024年第4期18卷 103-110页

作者： Mathias Fessler Qingxian su Marlene mark Jensen Yifeng Zhang Department of Environmental and Resource Engineering Technical University of DenmarkCopenhagenDK-2800Denmark

Magnetotactic bacteria reside in sediments and stratified water *** are named after their ability to synthesize internal magnetic particles that allow them to align and swim along the Earth’s magnetic field ***,we show that two magnetotactic species,Magnetospirillum magneticum strain AMB-1 and Magnetospirillum gryphiswaldense strain MsR-1,are *** *** and *** were able to generate current in microbial fuel cells with maximum power densities of 27 and 11μW/m^(2),*** the presence of the electron shuttle resazurin both species were able to reduce the crystalline iron oxide hematite(Fe_(2)O_(3)).In addition,*** could reduce poorly crystalline iron oxide(FeOOH).Our study adds *** and *** to the growing list of known electroactive bacteria,and implies that electroactivity might be common for bacteria within the Magnetospirillum genus.

关键词： Magnetotactic bacteria Magnetospirillum magneticum Magnetospirillum gryphiswaldense Extracellular electron transfer Microbial fuel cells

Olympic Games and 24-hour movement behaviors:A match worth making

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Journal of sport and Health science 2024年第6期13卷 728-731页

作者： mark.s.Tremblay Nicholas Kuzik mark.s J.Duncan Diego Augusto santos silva CHEO Research Institute OttawaON K1H 8L1Canada Department of Pediatrics University of OttawaOttawaON K1H 8L1Canada Federal University of santa Catarina FlorianopolisSanta Catarina 88040-900Brazil

*** The Olympic motto,"Faster,Higher,stronger-Together",represents the pursuit of athletic excellence,united as a global community."Excellence,respect and friendship"are the Olympic *** the motto and values are multifaceted and holistic in nature,and all-encompassing in their reach while recognizing no single entity rises above the ***,these foundational statements anchor the Olympic movement in its quest to build a better world through sport.

关键词： movement Together pursuit

Towards precision 24-hour movement behavior recommendations—The next new paradigm?

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Journal of sport and Health science 2024年第6期13卷 743-748页

作者： mark.s.Tremblay mark.s J.Duncan Nicholas Kuzik Diego Augusto santos silva Valerie Carson CHEO Research Institute OttawaON K1H 8L1Canada Department of Pediatrics University of OttawaOttawaON K1H 8L1Canada Federal University of santa Catarina Santa Catarina 88040900Brazil Faculty of Kinesiology Sportand RecreationUniversity of AlbertaEdmontonAB T6G 2H9Canada

*** The importance of physical activity(PA)for health is unequivocal.^(1)Accordingly,population-based recommendations for exercise,and more recently public health guidelines for PA,have been developed and released by authoritative groups for many decades.^(2)such guidelines emerged with leadership from the exercise physiology discipline and were rooted in,and loyal to,the importance of moderate-to-vigorous intensity PA(MVPA)or exercise.

关键词： movement behavior exercise

Extremely thin but very robust:surprising cryptogam trait combinations at the end of the leaf economics spectrum

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Plant Diversity 2024年第5期46卷 621-629页

作者： Tana Wuyun Lu Zhang Tiina Tosens Bin Liu Kristiina mark JoséÁngel Morales-sanchez Jesamine Jöneva Rikisahedew Vivian Kuusk Ülo Niinemets Institute of Agricultural and Environmental sciences Estonian University of Life SciencesKreutzwaldi 1Tartu 51014Estonia College of Landscape and Architecture Zhejiang A&F University666 Wusu StreetHangzhou 311300China Estonian Academy of sciences Kohtu 6Tallinn 10130Estonia

Leaf economics spectrum(LEs)describes the fundamental trade-offs between leaf structural,chemical,and physiological ***,structurally robust thick leaves with high leaf dry mass per unit area(LMA)exhibit lower photosynthetic capacity per dry mass(Amass).Paradoxically,“soft and thinleaved”mosses and spikemosses have very low Amass,but due to minute-size foliage elements,their LMA and its components,leaf thickness(LT)and density(LD),have not been systematically ***,we characterized LEs and associated traits in cryptogams in unprecedented details,covering five evolutionarily different *** found that mosses and spikemosses had the lowest LMA and LT values ever measured for terrestrial *** a broad range of species from different lineages,Amass and LD were negatively *** contrast,Amass was only related to LMA when LMA was greater than 14 g cm^(-2).In fact,low Amass reflected high LD and cell wall thickness in the studied *** conclude that evolutionarily old plant lineages attained poorly differentiated,ultrathin mesophyll by increasing *** plant lineages,LD,not LMA,is the trait that represents the trade-off between leaf robustness and physiology in the LEs.

关键词： Investment strategy Leaf density Leaf structural traits LMA estimation bias Non-seed plants Trait trade-offs