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Environmental landscape determinants of maximum forest canopy height of boreal forests

Journal of Plant Ecology 2019年第1期12卷 96-102页

作者： Lingfeng Mao Christopher W.Bater john jstadt Barry White Piotr Tompalski Nicholas C.Coops Scott E.Nielsen Department of Renewable Resources University of AlbertaEdmontonAlberta T6G 2H1Canada Forest Management Branch Forestry DivisionAlberta Agriculture and ForestryEdmontonAlberta T5K 2M4Canada Department of Forest Resource Management University of British ColumbiaVancouverBritish Columbia V6T 1Z4Canada

Aims Canopy height is a key driver of forest biodiversity and carbon *** estimates of canopy height are needed for assess-ing mechanisms relating to ecological patterns and processes of tree height *** global scales forest canopy height patterns are largely controlled by climate,while local variation at fine scales is due to differences in disturbance history and local patterns in envir-onmental *** relative effect of local environmental driv-ers on canopy height is poorly understood partly due to gaps in data on canopy height and methods for examining limiting ***,we used airborne laser scanning(ALS)data on vegetation structure of boreal forests to examine the effects of environmental factors on potential maximum forest canopy *** Relationships between maximum canopy height from ALS meas-ures and environmental variables were examined to assess factors limiting tree ***,we used quantile regression at the 0.90 quantile to relate maximum canopy height with environmental characteristics of climate(*** annual temperature[MAT]and mean annual precipitation),terrain(***)and depth-to-water(DTW)across a 33000 km2 multiple use boreal forest landscape in northeast Alberta,*** Findings Maximum canopy height was positively associated with MAT,ter-rain slope and terrain-derived DTW,collectively explaining 33.2%of the variation in *** strongest explanatory variable was DTW explaining 26%of canopy height variation with peatland forests having naturally shorter maximum canopy heights,but also more sites currently at their maximum potential *** con-trast,the most productive forests(*** to xeric upland forests)had the fewest sites at their potential maximum height,illustrating the effects of long-term forest management,wildfires and general anthropogenic footprints on reducing the extent and abundance of older,taller forest habitat in Alberta’s boreal forest.

关键词： forest succession vegetation structure quantile regression remote sensing airborne laser scanning(ALS)

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Challenges and Opportunities in Preserving Key Structural Features of 3D-Printed Metal/Covalent Organic Framework

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Nano-Micro Letters 2024年第8期16卷 362-381页

作者： Ximeng Liu Dan Zhao john Wang Department of Materials Science and Engineering National University of SingaporeSingapore 117574Singapore Department of Chemical and Biomolecular Engineering National University of SingaporeSingapore 117585Singapore National University of Singapore(Chongqing)Research Institute Chongqing 401123People’s Republic of China

Metal-organic framework(MOF)and covalent organic framework(COF)are a huge group of advanced porous materials exhibiting attractive and tunable microstructural features,such as large surface area,tunable pore size,and functional surfaces,which have significant values in various application *** emerging 3D printing technology further provides MOF and COFs(M/COFs)with higher designability of their macrostructure and demonstrates large achievements in their performance by shaping them into advanced 3D ***,the currently available 3D printing M/COFs strategy faces a major challenge of severe destruction of M/COFs’microstructural features,both during and after 3D *** is envisioned that preserving the microstructure of M/COFs in the 3D-printed monolith will bring a great improvement to the related *** this overview,the 3D-printed M/COFs are categorized into M/COF-mixed monoliths and M/COF-covered *** differences in the properties,applications,and current research states are *** up-to-date advancements in paste/scaffold composition and printing/covering methods to preserve the superior M/COF microstructure during 3D printing are further discussed for the two types of 3D-printed M/*** the analysis of the current states of 3D-printed M/COFs,the expected future research direction to achieve a highly preserved microstructure in the 3D monolith is proposed.

关键词： Metal-organic frameworks Covalent organic frameworks 3D printing Microstructure Monolith

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Experimental and analytical investigation on friction resistance force between buried coated pressurized steel pipes and soil

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Frontiers of Structural and Civil Engineering 2024年第4期18卷 615-629页

作者： Shaurav ALAM Tanvir MANZUR john MATTHEWS Chris BARTLETT Erez ALLOUCHE Brent KEIL john KRAFT Department of Civil Engineering and Construction Engineering Technology Louisiana Tech UniversityRustonLA 71270USA Department of Civil Engineering Bangladesh University of Engineering and TechnologyDhaka 1000Bangladesh Georgia Tech Research Institute AtlantaGA 30332USA Stantec Inc. Edmonton T5J0K4Canada North West Pipe Company VancouverWA 98684USA

This paper presents an analytical approach for estimating frictional resistance to pipe movement at soil and external pipe surface of buried coated pressurized steel pipes relative to the internal thrust *** proposed analytical method was developed based on 36 experiments,which involved three coating types(cement mortar(CM),polyurethane type-I(PT-I),prefabricated plastic tape(PPT))on pipes’surfaces,three different soils(pea-gravel(PG),sand(S),silty-clay(SC)),and four simulated over burden depths above the pipe’s *** showed frictional resistance decreased with increasing over burden depth above the pipe’s *** degree of frictional resistance at the pipe-soil interface was found to be in the order of PG>SC>S for all coating variations and overburden *** coated pipe buried in all three types of soil produced significantly higher frictional resistance as compared to other coating *** on experimental data,the developed analytical introduced a dimensionless factor“Z”,which included effects of types of coatings,soil,and overburden depths for simplified rapid *** showed that the method provided a better prediction of frictional resistance forces,in comparison to previous analytical methods,which were barely close in predicting friction resistance for different coating variations,soil types,and overburden *** resistance force values reported herein could be considered conservative.

关键词： friction resistance force thrust force coated pressurized steel pipe soil type overburden depth

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A Population Dynamics Approach to the Distribution of Space Debris in Low Earth Orbit

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Communications on Applied Mathematics and Computation 2024年第1期6卷 340-353页

作者： john Jurkiewicz Peter Hinow Department of Mathematical Sciences University of Wisconsin-MilwaukeeMilwaukeeWI53201USA

The presence of the debris in the Earth’s orbit poses a significant risk to human activity in outer *** debris population continues to grow due to ground launches,the loss of external parts from space ships,and uncontrollable collisions between objects.A computationally feasible continuum model for the growth of the debris population and its spatial distribution is therefore *** we propose a diffusion-collision model for the evolution of the debris density in the low-Earth orbit and its dependence on the ground-launch *** parametrize this model and test it against data from publicly available object catalogs to examine timescales for the uncontrolled ***,we consider sensible launch policies and cleanup strategies and how they reduce the future risk of collisions with active satellites or space ships.

关键词： Population dynamics Space debris Kessler syndrome Diffusion Low-Earth orbit

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Surgical treatment of inflammatory bowel disease:From the gastroenterologist’s stand-point

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World Journal of Gastrointestinal Surgery 2024年第5期16卷 1235-1254页

作者： john K Triantafillidis Inflammatory Bowel Disease Unit “Metropolitan General”HospitalHolargos 15562AtticaGreece Hellenic Society of Gastrointestinal Oncology Haidari 12461AthensGreece

Treatment of ulcerative colitis(UC)and Crohn’s disease(CD)represents,in the majority of cases,a real challenge to the gastroenterologist’s abilities and skills as well as a clinical test concerning his/her levels of medical knowledge and *** the last two decades,our pharmaceutical arsenal was significantly strengthened,especially after the introduction of the so-called biological agents,drugs which to a large extent not only improved the results of conservative treatment but also changed the natural history of the ***,colectomy is still necessary for some patients with severe UC although smaller compared to the past,precisely because of the improvements achieved in the available conservative ***,surgeries to treat colon dysplasia and cancer are increasing to some *** the same time,satisfactory improvements in surgical techniques,the pre-and post-operative care of patients,as well as the selection of the appropriate time for performing the surgery have been *** patients with CD,the improvement of conservative treatment did not significantly change the need for surgical treatment since two-thirds of patients need to undergo surgery at some point in the course of their *** the other hand,the outcome of the operation has improved through good preoperative care as well as the wide application of more conservative surgical techniques aimed at keeping as much of the bowel in situ as *** article discusses the indications for surgical management of UC patients from the gastroenterologist’s point of view,the results of the emerging new techniques such as transanal surgery and robotics,as well as alternative operations to the classic ileo-anal-pouch *** author also discusses the basic principles of surgical management of patients with CD based on the results of the relevant *** self-evident is emphasized,that is,to achieve an excellent therapeutic result in patients with se

关键词： Inflammatory bowel disease Ulcerative colitis Crohn’s disease Surgery Treatment Ileo-anal-pouch anastomosis Indications Techniques

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Study of hybrid nanofluid flow in a stationary cone-disk system with temperature-dependent fluid properties

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Applied Mathematics and Mechanics(English Edition) 2024年第4期45卷 677-694页

作者： A.S.john B.MAHANTHESH G.LORENZINI Center for Mathematical Needs Department of MathematicsCHRIST(Deemed to be University)Karnataka 560029India School of Mathematical and Statistical Sciences The University of Texas Rio Grande ValleyTexas 78539U.S.A. Department of Engineering and Architecture University of ParmaParma 43124Italy

Cone-disk systems find frequent use such as conical diffusers,medical devices,various rheometric,and viscosimetry *** this study,we investigate the three-dimensional flow of a water-based Ag-Mg O hybrid nanofluid in a static cone-disk system while considering temperature-dependent fluid *** the variable fluid properties affect the dynamics and heat transfer features is studied by Reynolds's linearized model for variable viscosity and Chiam's model for variable thermal *** single-phase nanofluid model is utilized to describe convective heat transfer in hybrid nanofluids,incorporating the experimental *** model is developed as a coupled system of convective-diffusion equations,encompassing the conservation of momentum and the conservation of thermal energy,in conjunction with an incompressibility condition.A self-similar model is developed by the Lie-group scaling transformations,and the subsequent self-similar equations are then solved *** influence of variable fluid parameters on both swirling and non-swirling flow cases is ***,the Nusselt number for the disk surface is *** is found that an increase in the temperature-dependent viscosity parameter enhances heat transfer characteristics in the static cone-disk system,while the thermal conductivity parameter has the opposite effect.

关键词： hybrid nanofluid cone-disk system laminar flow variable fluid property Nusselt number

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Does photobiomodulation require glucose to work effectively?

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Neural Regeneration Research 2024年第5期19卷 945-946页

作者： Jaimie Hoh Kam john Mitrofanis UniversitéGrenoble Alpes Fonds de Dotation ClinatecGrenobleFrance University College London Institute of OphthalmologyUK

A main requirement for cells to function normally is the availability of ***,available either direct from circulation or storage,is converted to the essential energy that cells need to drive critical intrinsic *** cells are deprived of glucose,they become dysfunctional and suffer ***,the use of specific wavelengths of light on body tissues,has been shown to promote,through small organelles called mitochondria,the metabolism of glucose to make energy for cells;this energy can be used to improve cell function and *** this perspective,we hypothesize that the availability of glucose is central to the core mechanism of photobiomodulation;that photobiomodulation is at its most efficient in stimulating mitochondrial activity and improving cell function when there is glucose readily available.

关键词： metabolism distress stimulating

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Optimizing oncolytic virus design:a“Swiss army knife”approach to create a systemically delivered therapeutic

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Signal Transduction and Targeted Therapy 2024年第5期9卷 1791-1792页

作者： Carolina S.Ilkow john Cameron Bell Ottawa Hospital Research Institute 501 Smyth RoadOttawaONK1H 8L6Canada

In a recent paper published in Nature Biotechnology,Chen et al.1 describe a multiplex oncolytic virus platform that coupled with adoptive T cell therapy could solve the problem of repeat,systemic delivery of virus based *** is widely accepted that multi-targeted therapeutic approaches attacking several facets of cancer biology are necessary to effectively deal with the tumor heterogeneity that exists within and between patients.

关键词： therapeutic al. targeted

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Stable hydrogen isoscape in precipitation generated using data fusion for East China

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Science China Earth Sciences 2024年第9期67卷 2972-2988页

作者： Jiacheng CHEN Jie CHEN Xunchang john ZHANG Peiyi PENG State Key Laboratory of Water Resources Engineering and Management Wuhan UniversityWuhan 430072China Hubei Key Laboratory of Water System Science for Sponge City Construction Wuhan UniversityWuhan 430072China USDA-ARS Oklahoma and Central Plains Agricultural Research Center El Reno OK 73036USA Southwest Research Institute for Hydraulic and Water Transport Engineering Chongqing Jiaotong UniversityChongqing 400016China

The stable hydrogen isotope in precipitation is an effective environmental tracer for climatic and hydrologic ***,accurate and high-precision precipitation hydrogen isoscapes are currently unavailable in *** this study,a data fusion method based on Convolutional Neural Networks(CNN)is used to fuse the hydrogen isotopic composition(δ^(2)H_(p))of observations and isotope-equipped general circulation model(iGCM)simulations.A precipitation hydrogen isoscape with a temporal resolution of monthly and a spatial resolution of 50-60 km is established for East China for the 1969-2017 *** to building the isoscape,the performance of three data fusion methods(DFMs)and two bias correction methods(BCMs)is *** results indicate that the CNN fusion method performs the best with a correlation coefficient larger than 0.90 and root mean square error smaller than 10.5‰ when using observation as a *** fusion methods based on back propagation and long short-term memory neural network perform similarly,while slightly outperforming the bias correction ***,the CNN method is used to generate the hydrogen isoscape,and the temporal and spatial distribution characteristics of the hydrogen isotope in precipitation are analyzed based on this *** generated isoscape shows similar spatial and temporal distribution characteristics to *** general,the distribution pattern of δ^(2)H_(p) is consistent with the temperature effect in northern China,and consistent with the precipitation amount effect in southern *** trend of the δ^(2)H_(p) time series is consistent with that of observed precipitation and ***,the generated isoscape effectively reproduces the observations,and has the characteristics of time continuity and relative spatial regularity,which can provide valuable data support for tracking atmospheric and hydrological processes.

关键词： Precipitation Precipitation isotope General circulation model Data fusion Dataset

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Nonuniform Dependence on the Initial Data for Solutions of Conservation Laws

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Communications on Applied Mathematics and Computation 2024年第1期6卷 489-500页

作者： john M.Holmes Barbara Lee Keyfitz Department of Mathematics The Ohio State UniversityColumbusOH43210USA

In this paper,we study systems of conservation laws in one space *** prove that for classical solutions in Sobolev spaces H^(s),with s>3/2,the data-to-solution map is not uniformly *** results apply to all nonlinear s... 详细信息

关键词： Conservation laws Data-to-solution map Nonuniform dependence

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