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Can a multistage approach improve individual tree mortality predictions across the complex mixed-species and managed forests of eastern North America?

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Forest Ecosystems 2023年第1期10卷 21-30页

作者： Cen Chen John Kershaw Jr aaron weiskittel Elizabeth McGarrigle Center for Research on Sustainable Forests University of MaineOronoME04469USA Faculty of Forestry&Environmental Management University of New BrunswickFrederictonNBE3B 5A3Canada Nova Scotia Department of Natural Resources HalifaxNSB3J 3M8Canada

Tree mortality plays a fundamental role in the dynamics of forest ecosystems,yet it is one of the most difficult phenomena to accurately *** modeling strategies have been developed to improve individual tree mortality *** less explored strategy is the use of a multistage modeling *** improvements from this approach have remained largely *** this study,we developed a novel multistage approach and compared its performance in individual tree mortality predictions with a more conventional approach using an identical individual tree mortality model *** permanent plot data(n=9442)covering the Acadian Region of North America and over multiple decades(1965–2014)were used in this *** results indicated that the model behavior with the multistage approach better depicted the observed mortality and showed a notable improvement over the conventional *** difference between the observed and predicted numbers of dead trees using the multistage approach was much smaller when compared with the conventional *** addition,tree survival probabilities predicted by the multistage approach generally were not significantly different from the observations,whereas the conventional approach consistently underestimated mortality across species and overestimated tree survival probabilities over the large range of DBH in the *** new multistage approach also predictions of zero mortality in individual plots,a result not possible in conventional ***,the new approach was more tolerant of modeling errors because it based estimates on ranked tree mortality rather than error-prone predicted ***,this new multistage approach deserves to be considered and tested in future studies.

关键词： Tree mortality modeling Mortality disaggregation Mixed effect model Annualization Mixed forests

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Examining approaches for modeling individual tree growth response to thinning in Norway spruce

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Forest Ecosystems 2022年第5期9卷 630-638页

作者： Christian Kuehne aaron R.weiskittel Aksel Granhus Norwegian Institute of Bioeconomy Research Division of Forestry and Forest ResourcesP.O.Box 115NO-1431ÅsNorway University of Maine Center for Research on Sustainable Forests5755 Nutting HallOronoME04469USA

Using periodic measurements from permanent plots in non-thinned and thinned Norway spruce(Picea abies(L.)***.)stands in Norway,individual-tree growth models were developed to predict annual diameter increment,height increment,and height to crown base *** on long-term data across a range of thinning regimes and stand conditions,alternative approaches for modeling response to treatment were *** thinning response functions in the form of multiplicative modifiers that predict no effect at the time of thinning,a rapid increase followed by an early maximum before the effect gradually declines to zero could not be fitted to initially derived baseline models without thinning related ***,alternative approaches were used and found to perform ***,indicator variables representing varying time periods after thinning were statistically significant and behaved in a robust manner as well as consistent with general *** addition,they improved overall prediction accuracy when incorporated as fixed effects into the baseline models for diameter and height to crown base ***,more simply,including exponentially decreasing multiplicative thinning response functions improved prediction accuracy for height increment and height to crown base *** of studied attribute and modelling approach,improvement in performance of these extended models was relatively limited when compared to the corresponding baseline models and more pronounced in trees from thinned *** conclude that the largely varying and often multi-year measurement intervals of the periodic data used in this study likely prevented the development of more sophisticated thinning response ***,based on the evaluation of the final models’overall performance such complex response functions may not to be necessary to reliably predict individual tree growth after thinning for certain conditions or species,which should be f

关键词： Growth modeling Treatment response functions Multiplicative modifiers Picea abies Norway

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Development and evaluation of an individual tree growth and yield model for the mixed species forest of the Adirondacks Region of New York, USA

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Forest Ecosystems 2017年第1期4卷 66-82页

作者： aaron weiskittel Christian Kuehne John Paul McTague Mike Oppenheimer University of Maine School of Forest Resources Orono ME 04469 USA. Rayonier Forest Research Center Yulee FL 32041 USA Rayonier Foresl Resources Fernandina Beach FL 32035 USA. University of Maine 5755 I Nutting Hall Orono ME 04469-5755 USA.

Background： Growth and yield models are important tools for forest planning. Due to its geographic location, topology, and history of management, the forests of the Adirondacks Region of New York are unique and complex. However, only a relatively limited number of growth and yield models have been developed and/or can be reasonably extended to this region currently. Methods： in this analysis, 571 long-term continuous forest inventory plots with a total of 10 - 52 years of measurement data from four experimental forests maintained by the State University of New York College of Environmental Science and Forestry and one nonindustrial private forest were used to develop an individual tree growth model for the primary hardwood and softwood species in the region. Species-specific annualized static and dynamic equations were developed using the available data and the system was evaluated for long-term behavior. Results： Equivalence tests indicated that the Northeast Variant of the Forest Vegetation Simulator （FVS-NE） was biased in its estimation of tree total and bole height, diameter and height increment, and mortality for most species examined. In contrast, the developed static and annualized dynamic, species-specific equations performed quite well given the underlying variability in the data. Long-term model projections were consistent with the data and suggest a relatively robust system for prediction. Conclusions： Overall, the developed growth model showed reasonable behavior and is a significant improvement over existing models for the region. The model also highlighted the complexities of forest dynamics in the region and should help improve forest planning efforts there.

关键词： Individual tree growth model Mixed species Forest vegetation simulator

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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

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Assessing gully erosion and rehabilitation using multi temporal LiDAR DEMs:Case study from the Great Barrier Reef catchments,Australia

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International Soil and Water Conservation Research 2024年第1期12卷 184-199页

作者： Sana Khan Rebecca Bartley Anne Kinsey-Henderson aaron Hawdon The Commonwealth Scientific and Industrial Research Organisation(CSIRO) Environment1 James Cook DrDouglas4814Australia The Commonwealth Scientific and Industrial Research Organisation(CSIRO) EnvironmentGPO Box 2583BrisbaneQLD4001Australia

Millions of dollars are being spent on gully rehabilitation to help reduce excess fine sediment delivery to the Great Barrier Reef(GBR).There is an urgent need for(i)prioritisation of active gullies for rehabilitation and(ii)the development of methodologies to inform the effectiveness of *** this study we analyse DEMs of Difference derived from 0.5 m resolution 2-3 year interval multi-temporal LiDAR data collected pre and post rehabilitation at three variable gully morphologies in the Burdekin *** analysis indicates that the highest annual average fine sediment erosion rates for the untreated control gullies occur at the linear gully(53.38 t ha^(-1)y^(-1))followed by linear-alluvial gully(34.24 t ha^(-1)y^(-1))and least at the alluvial gully(14.41 t ha^(-1)y^(-1)).The proportional loss or export of fine sediment from the gullies in their un-treated condition ranges from∼68 to 90%of what is eroded,and when the gullies are treated the proportion of fine sediment that is retained in the gully proportional to what is eroded increases to∼60%at all *** pre-treatment baseline erosion rates,and additional post treatment LiDAR captures,it is difficult to quantify the treatment *** results offer insights in the erosion mechanisms within different geomorphic gully morphologies and rehabilitation effects in these erosional *** study provides crucial knowledge of gully dynamics that can be coupled with other lines of evidence for better prioritisation of rehabilitation in the GBR catchments.

关键词： Digital elevation models (dis)connectivity Restoration Geomorphic change detection Geomorphic effectiveness GIS

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Dietary fibre effects and the interplay with exogenous carbohydrases in poultry nutrition

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Animal Nutrition 2024年第1期16卷 231-240页

作者： Michael R.Bedford Birger Svihus aaron J.Cowieson AB Vista Feed Ingredients Ltd Norwegian University of Life Sciences DSM Nutritional Products

A comprehensive understanding of the role of dietary fibre in non-ruminant animal production is elusive. Equivocal and conflated definitions of fibre coupled with significant analytical complexity,interact with poorly defined host and microbiome relationships. Dietary fibre is known to influence gut development, feed intake and passage rate, nutrient absorption, microbiome taxonomy and function, gut p H, endogenous nutrient loss, environmental sustainability, animal welfare and more. Whilst significant gaps persist in our understanding of fibre in non-ruminant animal production, there is substantial interest in optimizing the fibre fraction of feed to induce high value phenotypes such as improved welfare,live performance and to reduce the environmental footprint of animal production systems. In order to achieve these aspirational goals, it is important to tackle dietary fibre with the same level of scrutiny as is currently done for other critical nutrient classes such as protein, minerals and vitamins. The chemical,mechanical and nutritional role of fibre must be explored at the level of monomeric sugars, oligosaccharides and polysaccharides of varying molecular weight and decoration, and this must be in parallel to standardisation of analytical tools and definitions for speciation. To further complicate subject, exogenous carbohydrases recognise dietary fibre as a focal substrate and have varying capacity to generate lower molecular weight carbohydrates that interact differentially with the host and the enteric microbiome. This short review article will explore the interactive space between dietary fibre and exogenous carbohydrases and will include their nutritional and health effects with emphasis on functional development of the gut, microbiome modulation and host metabolism.

关键词： Fibre Carbohydrase Nutrition Microbiome Gastro-intestinal development Feed

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Unveiling ferroptosis as a promising therapeutic avenue for colorectal cancer and colitis treatment

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Acta Pharmaceutica Sinica B 2024年第9期14卷 3785-3801页

作者： aaron T.Kaoy Christian V.Cabanlongy Kendra Padilla Xiang Xue Department of Biochemistry and Molecular Biology University of New MexicoAlbuquerqueNM 87131USA

Ferroptosis is a novel type of regulated cell death(RCD)involving iron accumulation and lipid *** its discovery in 2012,various studies have shown that ferroptosis is associated with the pathogenesis of various *** cell death has also been linked to intestinal dysfunction but can act as either a positive or negative regulator of intestinal disease,depending on the cell type and disease *** continued investigation of mechanisms underlying ferroptosis provides a wealth of potential for developing novel *** the growing prevalence of intestinal diseases,particularly colorectal cancer(CRC)and inflammatory bowel disease(IBD),this review article focuses on potential therapeutics targeting the ferroptotic pathway in relation to CRC and IBD.

关键词： Ferroptosis Colorectal cancer Inflammatory bowel disease Cell death Molecular mechanisms Iron metabolism Drug therapies Targeted therapeutics

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H_(2)mediated mixed culture microbial electrosynthesis for high titer acetate production from CO_(2)

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Environmental Science and Ecotechnology 2024年第3期19卷 125-131页

作者： Yanhong Bian aaron Leininger Harold D.May Zhiyong Jason Ren Department of Civil and Environmental Engineering Princeton University86 Olden StPrincetonNJ08544United States Andlinger Center for Energy and the Environment Princeton University86 Olden St.PrincetonNJ08544United States

Microbial electrosynthesis(MES)converts CO_(2)into value-added products such as volatile fatty acids(VFAs)with minimal energy use,but low production titer has limited scale-up and *** electron transfer via H_(2)on the MES cathode has shown a higher conversion rate than the direct biofilm-based approach,as it is tunable via cathode potential control and accelerates electrosynthesis from CO_(2).Here we report high acetate titers can be achieved via improved in situ H_(2)supply by nickel foam decorated carbon felt cathode in mixed community MES *** concentration of 12.5 g L^(-1)was observed in 14 days with nickel-carbon cathode at a poised potential of-0.89 V(*** hydrogen electrode,SHE),which was much higher than cathodes using stainless steel(5.2 g L^(-1))or carbon felt alone(1.7 g L^(-1))with the same projected surface area.A higher acetate concentration of 16.0 g L^(-1)in the cathode was achieved over long-term operation for 32 days,but crossover was observed in batch operation,as additional acetate(5.8 g L^(-1))was also found in the abiotic anode *** observed the low Faradaic efficiencies in acetate production,attributed to partial H_(2)utilization for *** selective acetate production with high titer demonstrated in this study shows the H_(2)-mediated electron transfer with common cathode materials carries good promise in MES development.

关键词： Microbial electrosynthesis Indirect electron transfer CO_(2)electrolysis VFAs production

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Evaluation of large language models for the classification of medical device software

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Bio-Design and Manufacturing 2024年第5期7卷 819-822页

作者： Yu Han aaron Ceross Florence Bourgeois Paulo Savaget Jeroen H.M.Bergmann Department of Engineering Science University of OxfordOld Road CampusOxford OX37QDUK Harvard-MIT Center for Regulatory Science Harvard Medical SchoolBostonMAUSA Computational Health Informatics Program(CHIP) Boston Children’s HospitalBostonMAUSA Department of Technology and Innovation The University of Southern DenmarkOdenseDenmark

Amidst the rapidly expanding integration of large language models(LLMs)across various sectors(ranging from everyday applications to specialized fields demanding stringent regulatory adherence),our investigation seeks to determine how well these models can support medical device software *** device classification functions to systematically categorize devices according to their designated use,associated risk levels,and requisite regulatory oversight,thereby providing a structured framework for ensuring safety and efficacy as mandated by regulatory authorities.

关键词： everyday demanding thereby

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An examination of thematic research,development,and trends in remote sensing applied to conservation agriculture

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International Soil and Water Conservation Research 2024年第1期12卷 77-95页

作者： Zobaer Ahmed aaron Shew Lawton Nalley Michael Popp V.Steven Green Kristofor Brye Center for Advanced Spatial Technologies University of ArkansasFayettevilleARUSA Environmental Dynamics Program University of ArkansasFayettevilleARUSA Department of Agricultural Economics and Agribusiness University of ArkansasFayettevilleARUSA College of Agriculture Arkansas State UniversityJonesboroARUSA University of Arkansas System Division of Agriculture Little RockARUSA Department of Crop Soiland Environmental SciencesUniversity of ArkansasFayettevilleARUSA

Conservation agriculture seeks to reduce environmental degradation through sustainable management of agricultural *** the 1990s,agricultural research has been conducted using remote sensing technologies;however,few previous reviews have been conducted focused on different conservation management *** of the previous literature has focused on the application of remote sensing in agriculture without focusing exclusively on conservation practices,with some only providing a narrative review,others using biophysical remote sensing for quantitative estimates of the bio-geo-chemical-physical properties of soils and crops,and few others focused on single agricultural management *** paper used the preferred reporting items for systematic review(PRISMA)methodology to examine the last 30 years of thematic research,development,and trends associated with remote sensing technologies and methods applied to conservation agriculture research at various spatial and temporal scales.A set of predefined key concepts and keywords were applied in three databases:Scopus,Web of Science,and Google Scholar.A total of 188 articles were compiled for initial examination,where 68 articles were selected for final analysis and grouped into cover crops,crop residue,crop rotation,mulching,and tillage *** on conservation agriculture research using remote sensing have been increasing since 1991 and peaked at 10 publications in *** the 68 articles,94%used a pixel-based,while only 6%used an object-based classification *** to 2005,tillage practices were abundantly studied,then crop residue was a focused theme between 2004 and *** 2012 to 2020,the focus shifted again to cover *** spectral indices were used in 76%of the 68 *** examination offered a summary of the new potential and identifies crucial future research needs and directions that could improve the contribution of remote sensing to the provision of long-term operat

关键词： Remote sensing Conservation agriculture Classification algorithm Spatial resolution Satellite Spectral indices PRISMA

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