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Nanomanufacturing and Metrology 2022年第1期5卷 60-66页

作者： Nathan black David Edwards Niall browne Joseph G.M.Guy Niyorjyoti Sharma Kristina M・Holsgrove aaron b.naden Raymond G.P.McQuaid brian J.Rodriguez Amit Kumar School of Maths and Physics Queen's University BelfastBelfast BT7 INNUK School of Chemistry University of St.AndrewsSt Andrews KY169STUK School of Physics University College DublinBelfieldDublin 4Ireland

The realization of a mixed-phase microstructure in strained biFeO_(3)(bFO)thin films has led to numerous novel effects derived from the coexistence of the tetragonal-like monoclinic phase(T phase)and rhombohedral-like monoclinic phase(R phase).Strong strain and polarization diiferences between the phases should result in a high level of transformation plasticity,which enables the continuous alteration of the relative proportion of R and T states in response to external *** the potential for utilizing such plasticity to control mixed-phase populations under external stimuli is evident,direct experi・mental evidence backed by equilibrium predictions has not yet been fully *** we demonstrate deterministic control of mixed-phase populations in an epitaxially strained bFO thin film through the application of localized stresses and electric fields in a reversible manne匚The results illustrate and rationalize deterministic control of mixed phases in strained bFO films,which could be crucial in tuning their functional *** findings also highlight a new multiparametric technique in the scanning probe lithography toolbox based on tip-assisted electric and strain field manipulation of functional properties that might find application beyond the ferroelectric domain and structural phase lithography.

关键词： Phase competition Ferroelectric Stress Lithography

Importance of being Nernst: Synaptic activity and functional relevance in stem cell-derived neurons

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World Journal of Stem Cells 2015年第6期7卷 899-921页

作者： aaron b bradford Patrick M McNutt Cell/Molecular biology branch US Army Medical Research Institute of Chemical DefenseAberdeen Proving Grounds-EAMD 21010United States

Functional synaptogenesis and network emergence are signature endpoints of neurogenesis. These behaviors provide higher-order confirmation that biochemical and cellular processes necessary for neurotransmitter release, post-synaptic detection and network propagationof neuronal activity have been properly expressed and coordinated among cells. The development of synaptic neurotransmission can therefore be considered a defining property of neurons. Although dissociated primary neuron cultures readily form functioning synapses and network behaviors in vitro, continuously cultured neurogenic cell lines have historically failed to meet these criteria. Therefore, in vitro-derived neuron models that develop synaptic transmission are critically needed for a wide array of studies, including molecular neuroscience, developmental neurogenesis, disease research and neurotoxicology. Over the last decade, neurons derived from various stem cell lines have shown varying ability to develop into functionally mature neurons. In this review, we will discuss the neurogenic potential of various stem cells populations, addressing strengths and weaknesses of each, with particular attention to the emergence of functional behaviors. We will propose methods to functionally characterize new stem cell-derived neuron(SCN) platforms to improve their reliability as physiological relevant models. Finally, we will review how synaptically active SCNs can be applied to accelerate research in a variety of areas. Ultimately, emphasizing the critical importance of synaptic activity and network responses as a marker of neuronal maturation is anticipated to result in in vitro findings that better translate to efficacious clinical treatments.

关键词： Synapses Neurotransmission In vitrotechniques Induced pluripotent stem cells Neuronalnetworks Neurogenesis Neural stem cells Embryonicstem cells Induced neurons

DEM Fusion using a modified k-means clustering algorithm

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International Journal of Digital Earth 2016年第12期9卷 1242-1255页

作者： Colleen E.Fuss aaron A.berg John b.Lindsay Department of Geography University of GuelphGuelphCanada

Digital elevation models(DEMs)are a necessary dataset for modelling the Earth’s surface;however,all DEMs contain *** can reduce this error using DEM fusion techniques since numerous DEMs can be available for a ***,the use of a clustering algorithm in DEM fusion has not been previously *** this study a new DEM fusion algorithm based on a clustering approach that works on multiple DEMs to exploit consistency in the estimates as indicators of accuracy and precision is *** fusion approach includes slope and elevation thresholding,k-means clustering of the elevation estimates at each cell location,as well as filtering and smoothing of the fusion *** of the input DEMs,and the products of each step of the fusion algorithm,with a higher accuracy reference DEM enabled a detailed analysis of the effectiveness of the DEM fusion *** main findings of the research were:the k-means clustering of the elevations reduced the precision which also impacted the overall accuracy of the estimates;the number of final cluster members and the standard deviation of elevations before clustering both had a strong relationship to the error in the k-means estimates.

关键词： DEM fusion k-means clustering DEM error

An imputation/copula-based stochastic individual tree growth model for mixed species Acadian forests： a case study using the Nova Scotia permanent sample plot network

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Forest Ecosystems 2017年第4期4卷 251-263页

作者： John A. Kershaw Jr aaron R. Weiskittel Michael b. Lavigne Elizabeth McGarrigle University of New brunswick FrederictonNBCanada University of Maine OroooMEUSA Atlantic Forestry Centre Natural Resources Canada.FrederiaooNBCanada Nova Scotia Natural Resources Forestry DivisionTruroNS B2N 0G9UK.

background： A novel approach to modelling individual tree growth dynamics is proposed. The approach combines multiple imputation and copula sampling to produce a stochastic individual tree growth and yield projection system. Methods： The Nova Scotia, Canada permanent sample plot network is used as a case study to develop and test the modelling approach. Predictions from this model are compared to predictions from the Acadian variant of the Forest Vegetation Simulator, a widely used statistical individual tree growth and yield model. Results： Diameter and height growth rates were predicted with error rates consistent with those produced using statistical models. Mortality and ingrowth error rates were higher than those observed for diameter and height, but also were within the bounds produced by traditional approaches for predicting these rates. Ingrowth species composition was very poorly predicted. The model was capable of reproducing a wide range of stand dynamic trajectories and in some cases reproduced trajectories that the statistical model was incapable of reproducing. Conclusions： The model has potential to be used as a benchmarking tool for evaluating statistical and process models and may provide a mechanism to separate signal from noise and improve our ability to analyze and learn from large regional datasets that often have underlying flaws in sample design.

关键词： Nearest neighbor imputation Copula sampling Individual tree growth model Mortality Ingrowth Mixed species stand development Acadian forests Nova Scotia

Global optimal path planning for mobile robot based onimproved Dijkstra algorithm and ant system algorithm

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Journal of Central South University of Technology 2006年第1期13卷 80-86页

作者：谭冠政贺欢 aaron Sloman School of Information Science and Engineering Central South University Changsha 410083 China School of Computer Science The University of Birmingham Birmingham B15 2TT UK School of Information Science and Engineering Central South University Changsha 410083 China School of Computer Science The University of Birmingham Birmingham B15 2TT UK

A novel method of global optimal path planning for mobile robot was proposed based on the improved Dijkstra algorithm and ant system algorithm. This method includes three steps: the first step is adopting the MAKLINK graph theory to establish the free space model of the mobile robot, the second step is adopting the improved Dijkstra algorithm to find out a sub-optimal collision-free path, and the third step is using the ant system algorithm to adjust and optimize the location of the sub-optimal path so as to generate the global optimal path for the mobile robot. The computer simulation experiment was carried out and the results show that this method is correct and effective. The comparison of the results confirms that the proposed method is better than the hybrid genetic algorithm in the global optimal path planning.

关键词： mobile robot global optimal path planning improved Dijkstra algorithm ant system algorithm MAKLINK graph free MAKLINK line

balanced nutrient density for broiler chickens using a range of digestible lysine-to-metabolizable energy ratios and nutrient density:Growth performance,nutrient utilisation and apparent metabolizable energy

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Animal Nutrition 2021年第2期7卷 430-439页

作者： Reza barekatain Luis F.Romero JoséOtávio b.Sorbara aaron J.Cowieson South Australian Research and Development Institute Roseworthy CampusRoseworthySA5371Australia School of Animal and Veterinary Sciences Roseworthy CampusUniversity of AdelaideSA5371Australia Animal Nutrition and Health DSM Nutritional ProductsKaiseraugst4303Switzerland

Currently,specific nutrient concentration,metabolizable energy(ME)and digestible amino acids are used as feed formulation criteria.A balanced nutrient density(bND)concept based on 2 criteria of nutrient density and balanced amino acids-to-ME ratio may offer more flexibility in optimisation of profit in formulation of diets compared with current formulation based on set values per unit of feed mass.A total of 672 one-d-old off-sex male Ross 308 broiler chickens were used across two 42-d performance trials in a 3×2 factorial arrangement of treatments with each diet replicated 8 times(14 birds per replicate).The experimental factors were 2 nutrient density levels(low[LD]and high[HD])and 3 digestible lysine-to-ME ratios(DLYS:ME;low,medium,and high).Low density diets had ME of 2,876 and 3,023 kcal/kg for starter and finisher,respectively,while values for HD diets were 3,169 and 3,315 kcal/kg with proportionally higher non-nitrogenated *** digestibility and apparent metaboliz-able energy(AME)assays were conducted at d 21 and *** assays at d 7 were conducted on birds used for performance *** of the diet density,birds fed low DLYS:ME had a lower(Pbirds fed low and medium DLYS:ME had a similar body weight gain being the heaviest while birds low DLYS:ME were the *** an interaction(Pbserved for birds fed LD×low DLYS:ME and improved linearly when DLYS:ME increased to the highest level reaching a limit for birds fed HD×medium DLYS:*** conversion linearly decreased(Pbility were affected on d 21 and 42 but not on d 7 of *** the independence of response on bW and feed consumption,the use of bND as a flexible system in diet formulations has the potential to enable more accurate formulation for optimisation of growth performance

关键词： Nutrient density Metabolizable energy Lysine Digestibility Optimisation

Strategies towards robust interpretations of in situ zircon oxygen isotopes

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Geoscience Frontiers 2023年第2期14卷 241-255页

作者： Janne Liebmann Christopher L.Kirkland John b.Cliff Christopher J.Spencer aaron J.Cavosie Timescales of Mineral Systems Group The Institute for Geoscience Research(TIGeR)School of Earth and Planetary SciencesCurtin UniversityPerthAustralia Pacific Northwest National Laboratory RichlandWashington 99354United States Department of Geological Sciences and Geological Engineering Queen’s UniversityKingstonONCanada Space Science and Technology Centre The Institute for Geoscience Research(TIGeR)School of Earth and Planetary ScienceCurtin UniversityPerthAustralia

Oxygen isotopes are a versatile tool to address a wide range of questions in the Earth *** include geothermometry,paleoclimatology,tracing of geochemical reservoirs,fluid-rock interaction,magmatic petrogenesis,and identification of extra-terrestrial *** arguably provides one of the most robust records of primary magmatic O isotope ratio due to low diffusion rates in crystalline *** ability to correlate zircon O isotopes with temporal and petrogenetic information(e.g.U-Pb geochronology,Lu-Hf isotopes,and trace elements)makes this mineral a key archive for understanding Earth’s crustal ***,zircon O isotope geochemistry has found widespread usage to address fundamental questions across the earth and planetary *** general apparent ease of O isotopic acquisition through the advancement of rapid in situ techniques(*** ion mass spectrometry;SIMS)and associated dedicated national laboratories has led to the generation of large O isotopic data sets of variable quality,highlighting the importance of a coherent workflow for data collection,reduction,and *** paper presents a set of approaches for measurement,assessment,and reporting of zircon O isotope *** focus in this contribution is on in situ analysis via secondary ion mass spectrometry using large geometry instruments,but other commonly used techniques are briefly reviewed for *** work aims to provide an analytical framework necessary for geologically meaningful interpretation of O isotope *** addition,we describe inherent geological(***-induced disturbance of the zircon O isotopic system)and analytical(*** due to sample topography effects)challenges and outline means to identify and avoid such issues as a prerequisite to the generation of robust primary O isotopic signatures for geological interpretation.

关键词： In situ Oxygen isotopes Zircon SIMS Secondary ion mass spectrometry Off-mount standard

The role of decomposition reactions in assessing first-principles predictions of solid stability

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npj Computational Materials 2019年第1期5卷 1120-1128页

作者： Christopher J.bartel Alan W.Weimer Stephan Lany Charles b.Musgrave aaron M.Holder Department of Chemical and biological Engineering University of ColoradoBoulderCO 80309USA National Renewable Energy Laboratory GoldenCO 80401USA Department of Chemistry University of ColoradoBoulderCO 80309USA

The performance of density functional theory approximations for predicting materials thermodynamics is typically assessed by comparing calculated and experimentally determined enthalpies of formation from elemental phases,ΔH_(f).However,a compound competes thermodynamically with both other compounds and their constituent elemental forms,and thus,the enthalpies of the decomposition reactions to these competing phases,ΔH_(d),determine thermodynamic *** evaluated the phase diagrams for 56,791 compounds to classify decomposition reactions into three types:*** that produce elemental phases,*** that produce compounds,and *** that produce *** analysis shows that the decomposition into elemental forms is rarely the competing reaction that determines compound stability and that approximately two-thirds of decomposition reactions involve no elemental *** experimentally reported formation enthalpies for 1012 solid compounds,we assess the accuracy of the generalized gradient approximation(GGA)(PbE)and meta-GGA(SCAN)density functionals for predicting compound *** 646 decomposition reactions that are not trivially the formation reaction,PbE(mean absolute difference between theory and experiment(MAD)=70 meV/atom)and SCAN(MAD=59 meV/atom)perform similarly,and commonly employed correction schemes using fitted elemental reference energies make only a negligible improvement(~2 meV/atom).Furthermore,for 231 reactions involving only compounds(Type 2),the agreement between SCAN,PbE,and experiment is within~35 meV/atom and is thus comparable to the magnitude of experimental uncertainty.

关键词： stability stability solid

Nutritional deficiencies in the pediatric age group in a multicultural developed country,Israel

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World Journal of Clinical Cases 2014年第5期2卷 120-125页

作者： Motti Haimi aaron Lerner Children’s Health Center Clalit Health ServicesBruce and Ruth Rappaport School of MedicineTechnion-Israel Institute of Technology34369 HaifaIsrael Pediatric Gastroenterology and Nutrition Unit Carmel Medical CenterBruce and Ruth Rappaport School of MedicineTechnion- Israel Institute of Technology34369 HaifaIsrael

Nutrient deficiencies are prevalent *** and morbid conditions have been described to result from nutritional *** is essential to address nutrient deficiencies as these may lead to chronic longterm health problems such as rickets,iron deficiency anemia,goiter,obesity,coronary heart disease,type2 diabetes,stroke,cancer and *** the present review we surveyed the extent and severity of nutritional deficiencies in Israel through a selective and comprehensive Medline review of previous reports and studies performed during the last 40 *** populations have multiple nutritional deficiencies,including iron,calcium,zinc,folic acid,and vitamins b12,C,D and E,spanning all age groups,several minorities,and specific *** Israel,some of the nutrients are mandatorily implemented and many of them are implemented voluntarily by local *** suggest ways to prevent and treat the nutritional deficiencies,as a step to promote food fortification in Israel.

关键词： Nutrient deficiencies Type 2 diabetes Obesity Israel

An Interface-Capturing Regularization Method for Solving the Equations for Two-Fluid Mixtures

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Communications in Computational Physics 2013年第10期14卷 1322-1346页

作者： Jian Du Robert D.Guy aaron L.Fogelson Grady b.Wright James P.Keener Department of Mathematical Science Florida Institute of TechnologyMelbourneFL 32901USA Department of Mathematics University of UtahSalt Lake CityUT 84112USA Department of bioengineering University of UtahSalt Lake CityUT 84112USA Department of Mathematics University of California DavisDavisCA 95616USA Department of Mathematics Boise State UniversityBoiseID 83725USA

Many problems in biology involve gels which are mixtures composed of a polymer network permeated by a fluid solvent(water).The two-fluid model is a widely used approach to described gel mechanics,in which both network and solvent coexist at each point of space and their relative abundance is described by their volume *** phase is modeled as a continuum with its own velocity and constitutive *** some biological applications,free boundaries separate regions of gel and regions of pure solvent,resulting in a degenerate network momentum equation where the network volume fraction *** overcome this difficulty,we develop a regularization method to solve the two-phase gel equations when the volume fraction of one phase goes to zero in part of the computational domain.A small and constant network volume fraction is temporarily added throughout the domain in setting up the discrete linear equations and the same set of equation is solved *** equations are very poorly conditioned for small values of the regularization parameter,but the multigrid-preconditioned GMRES method we use to solve them is efficient and produces an accurate solution of these equations for the full range of relevant regularization parameter values.

关键词： Gel swelling preconditioner two-fluid model