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Electronics technology fundamentals

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C_4 Plants as Biofuel Feedstocks: Optimising Biomass Production and Feedstock Quality from a Lignocellulosic Perspective

2002年

作者： Paynter robert t.

来源：畅想之星图书光盘版（南... 评论

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Journal of Integrative Plant Biology 2011年第2期53卷 120-135页

作者： Caitlin S.Byrt Christopher P.L.Grof robert t.Furbank School of Environmental and Life Sciences University of NewcastleUniversity Drive CSIRO Plant Industry and High Resolution Plant Phenomics Centre

the main feedstocks for bioethanol are sugarcane （Saccharum offic- inarum） and maize （Zea mays）, both of which are C4 grasses, highly efficient at converting solar energy into chemical energy, and both are food crops. As the systems for lignocellulosic bioethanol production become more efficient and cost effective, plant biomass from any source may be used as a feedstock for bioethanol production. thus, a move away from using food plants to make fuel is possible, and sources of biomass such as wood from forestry and plant waste from cropping may be used. However, the bioethanol industry will need a continuous and reliable supply of biomass that can be produced at a low cost and with minimal use of water, fertilizer and arable land. As many C4 plants have high light, water and nitrogen use efficiency, as compared with C3 species, they are ideal as feedstock crops. We consider the productivity and resource use of a number of candidate plant species, and discuss biomass ＇quality＇, that is, the composition of the plant cell wall.

关键词： C4 Plants as Biofuel Feedstocks Optimising Biomass Production and Feedstock Quality from a Lignocellulosic Perspective

Stable Carbon Isotope Discrimination (δ¹³C) of Cotton Burrs and Seeds as a Season-Long Integrator of Crop Water Stress

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American Journal of Plant Sciences 2022年第12期13卷 1448-1459页

作者： Dennis C. Gitz III Jeffrey t. Baker robert J. Lascano Cropping Systems Research Laboratory ARS-USDA1 Lubbock USA

Plant-based irrigation management schemes typically use surrogates such as canopy temperature, alone, or in conjunction with environmental variables, to infer the degree of “crop stress” (biological strain) induced by drought. Few systematic studies of the relationship between “crop stress”, as defined by such surrogates, and physiological estimates of water use efficiency (WUE) exist over both daily and seasonal time scales relevant to agronomic irrigation control. the systematic application of stable carbon isotope discrimination (δ13C) might allow post hoc evaluation of irrigation scheduling schemes and might also be a useful germplasm screening tool if the source(s) of variability can be uncovered and/or controlled. Results from preliminary efforts comparing leaf and cotton seed δ13C to season-long water deficits showed that seeds are more useful indicators of season-long water stress and water use efficiency during crop development.

关键词： Irrigation-Scheduling Germplasm Screen Water Management

testing allometric scaling relationships in plant roots

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Forest Ecosystems 2020年第4期7卷 770-780页

作者： Qiang Deng Zhiyou Yuan Xinrong Shi t.Ryan Lock robert L.Kallenbach State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water ConservationChinese Academy of Sciences and Ministry of Water ResourcesYangling 712100ShaanxiChina. University of Chinese Academy of Sciences Beijing 100049China. Institute of Soil and Water Conservation Northwest A&F UniversityYangling 712100ShaanxiChina Division of Plant Sciences College of AgricultureFoodand Natural ResourcesUniversity of Missouri108 Waters HallColumbiaMO 65211USA.

Background:Metabolic scaling theory predicts that plant productivity and biomass are both ***,this theory has not yet been tested in plant ***:In this study,we tested how metabolic scaling occurs in plants using a comprehensive plant root dataset made up of 1016 observations from natural *** generated metabolic scaling exponents by logtransformation of root productivity versus ***:Results showed that the metabolic scaling exponents of fine root(ter)productivity versus biomass were close to 1.0 for all ecosystem types and functional *** exponents decreased in coarse roots(>2mm in diameter).Conclusions:We found isometric metabolic scaling in fine roots,a metabolically active organ similar to seedlings or *** findings also indicate a shift in metabolic scaling during plant ***,our study supports the absence of any unified single constant scaling exponent for metabolism-biomass relationships in terrestrial plants,especially for forests with woody species.

关键词： Allometry Biomass Metabolic scaling Plant roots Productivity

Wastewater surveillance provides 10-days forecasting of COVID-19 hospitalizations superior to cases and test positivity:A prediction study

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Infectious Disease Modelling 2023年第4期8卷 1138-1150页

作者： Dustin t.Hill Mohammed A.Alazawi E.Joe Moran Lydia J.bennett Ian Bradley Mary B.Collins Christopher J.Gobler Hyatt Green tabassum Z.Insaf Brittany Kmush Dana Neigel Shailla Raymond Mian Wang Yinyin Ye David A.Larsen Department of Public Health Syracuse UniversitySyracuseNY13244USA Center for Environmental Health New York State Department of HealthAlbanyNYUSA CDC Foundation AtlantaGAUSA Department of Civil Structural and Environmental EngineeringUniversity at BuffaloBuffaloNYUSA School of Marine and Atmospheric Sciences Sustainability Studies DivisionStony Brook UniversityStony BrookNYUSA Institute for Advanced Computational Science Stony Brook UniversityStony BrookNYUSA New York State Center for Clean Water technology Stony Brook UniversityStony BrookNYUSA School of Marine and Atmospheric Sciences Stony Brook UniversityStony BrookNYUSA Department of Environmental Biology State University of New York College of Environmental Science and ForestrySyracuseNYUSA Department of Epidemiology and Biostatistics School of Public HealthUniversity at AlbanyRensselaerNYUSA Department of Civil Engineering College of Engineering and Applied SciencesStony Brook UniversityStony BrookNYUSA

Background:the public health response to COVID-19 has shifted to reducing deaths and hospitalizations to prevent overwhelming health *** amount of SARS-CoV-2 RNA fragments in wastewater are known to correlate with clinical data including cases and hospital admissions for *** developed and tested a predictive model for incident COVID-19 hospital admissions in New York State using wastewater ***:Using county-level COVID-19 hospital admissions and wastewater surveillance covering 13.8 million people across 56 counties,we fit a generalized linear mixed model predicting new hospital admissions from wastewater concentrations of SARS-CoV-2 RNA from April 29,2020 to June 30,*** included covariates such as COVID-19 vaccine coverage in the county,comorbidities,demographic variables,and holiday ***:Wastewater concentrations of SARS-CoV-2 RNA correlated with new hospital admissions per 100,000 up to ten days prior to *** that included wastewater had higher predictive power than models that included clinical cases only,increasing the accuracy of the model by 15%.Predicted hospital admissions correlated highly with observed admissions(r¼0.77)with an average difference of 0.013 hospitalizations per 100,000(95%CI¼[0.002,0.025])Interpretation:Using wastewater to predict future hospital admissions from COVID-19 is accurate and effective with superior results to using case data *** lead time of ten days could alert the public to take precautions and improve resource allocation for seasonal surges.

关键词： COVID-19 hospitalizations Wastewater-based epidemiology Forecasting Prediction SARS-CoV-2

Hurricane disturbances, tree diversity, and succession in North Carolina Piedmont forests, USA

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Journal of Forestry Research 2019年第1期30卷 219-231页

作者： Weimin Xi robert K.Peet Michael t.Lee Dean L.Urban Department of Biology University of North Carolina at Chapel Hill Department of Biological and Health Sciences Texas A & M University-Kingsville the Nicholas School of the Environment Duke University

Windthrow plays a critical role in maintaining species diversity in temperate forests. Do large-scale strong wind events(i.e., tropical cyclones, including hurricanes,typhoons and severe cyclonic storms) increase tree diversity in severely damaged forest areas? Do hurricanes(tropical cyclones that occurs in the Atlantic Ocean and northeastern Pacific Ocean) lead to altered relative abundance of shade-tolerant and shade-intolerant species? Did historic hurricanes alter the succession trajectory of the damaged forests? We used nearly 70-year tree demographic data to assess the effects of two major hurricanes on woody species diversity in Piedmont forests, North Carolina, USA. Species richness(S) and Shannon–Wiener's diversity index(H') were used to evaluate the changes in tree diversity. the changes in composition were assessed with Nonmetric Multidimensional Scaling. the pre-hurricane successional phase can strongly influence both the damage severity and subsequent responses. Although there is often an immediate drop in diversity following a hurricane, understory tree diversity quickly increases to levels that exceed those prior to the disturbance. this leads to an increase in diversity in stands that were substantially damaged. Hurricanes significantly decrease the dominance of shade-intolerant canopy species while increasing preestablished, more shade-tolerant species. We conclude that large, and infrequent hurricanes help to maintain local tree diversity, but also accelerate the increase in dominance of understory species such as red maple and beech.

关键词： Wind disturbance tree species diversity Plant succession Disturbance-diversity relationship Piedmont forests

RF-based location of partial discharge sources using received signal features

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High Voltage 2019年第1期4卷 28-32页

作者： Ephraim t.Iorkyase Christos tachtatzis Ian A.Glover robert C.Atkinson Department of Electronic and Electrical Engineering University of StrathclydeRoyal College Building204 George StreetGlasgow G11XWUK Department of Engineering and technology University of HuddersfieldHD13DH HuddersfieldUK

Partial discharges(PDs)are symptomatic of some localised defects in the insulation system of electrical *** activity emits electrical pulses in the form of radio frequency(RF)signals which can be captured using appropriate *** analysis of the measured RF signals facilitates localisation of *** study investigates the plausibility of using purely RF received signal features of PD pulses to locate PD at low cost.A localisation approach based on the analysis of these features has been developed,with the assumption that PDs generate unique RF spatial patterns due to the complexities and nonlinearities of RF *** this approach,two distinct frequency bands which hold different PD information are *** location features are extracted from the main PD signal and the two sub-band ***-based feature selection(CFS)is employed for feature selection and dimensionality *** results show that PD location can be inferred from the features of the PD *** application of CFS to PD data reduces the memory/computational demand and improves localisation accuracy.

关键词： signal features electrical

New guidance for using t-SNE:Alternative defaults,hyperparameter selection automation,and comparative evaluation

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Visual Informatics 2022年第2期6卷 87-97页

作者： robert Gove Lucas Cadalzo Nicholas Leiby Jedediah M.Singer Alexander Zaitzeff two Six technologies USA

We present new guidelines for choosing hyperparameters for t-SNE and an evaluation comparing these guidelines to current *** guidelines include a proposed empirically optimum guideline derived from a t-SNE hyperparameter grid search over a large collection of data *** also introduce a new method to featurize data sets using graph-based metrics called scagnostics;we use these features to train a neural network that predicts optimal t-SNE hyperparameters for the respective data *** neural network has the potential to simplify the use of t-SNE by removing guesswork about which hyperparameters will produce the best *** evaluate and compare our neural network-derived and empirically optimum hyperparameters to several other t-SNE hyperparameter guidelines from the literature on 68 data *** hyperparameters predicted by our neural network yield embeddings with similar accuracy as the best current t-SNE *** our empirically optimum hyperparameters is simpler than following previously published guidelines but yields more accurate embeddings,in some cases by a statistically significant *** find that the useful ranges for t-SNE hyperparameters are narrower and include smaller values than previously reported in the ***,we also quantify the potential for future improvements in this area:using data from a grid search of t-SNE hyperparameters we find that an optimal selection method could improve embedding accuracy by up to two percentage points over the methods examined in this paper.

关键词： Dimensionality reduction Machine learning t-SNE

Cenozoic plants from tibet:An extraordinary decade of discovery,understanding and implications

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Science China Earth Sciences 2023年第2期66卷 205-226页

作者： Zhekun ZHOU Jia LIU Linlin CHEN robert A.SPICER Shufeng LI Jian HUANG Shitao ZHANG Yongjiang HUANG Linbo JIA Jinjin HU tao SU CAS Key Laboratory of tropical Forest Ecology Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMengla666303China CAS Key Laboratory for Plant Diversity and Biogeography of East Asia Kunming Institute of BotanyChinese Academy of SciencesKunming650204China School of Environment Earth and Ecosystem SciencesThe Open UniversityMilton KeynesMK76AAUK Faculty of Land Resource Engineering Kunming University of Science and TechnologyKunming650093China State Key Laboratory of Paleobiology and Stratigraphy Nanjing Institute of Geology and PaleontologyChinese Academy of SciencesNanjing210008China

Plant fossils play an important role in understanding landscape evolution across the tibetan Region,as well as plant diversity across wider eastern *** the last decade or so,paleobotanical investigations within the tibet Region have led to a paradigm shift in our understanding of how the present plateau formed and how this affected the regional climate and *** is because:(1)Numerous new taxa have been *** all the Cenozoic records of new plant fossil species reported from the tibet(Xizang)Autonomous Region 45 out of 63(70%)were documented after *** these,many represent the earliest records from Asia,or in some cases worldwide,at the genus or family level.(2)these fossils show that during the Paleogene,the region now occupied by the tibetan Plateau was a globally significant floristic exchange *** on paleobiogeographic studies,grounded by fossil evidence,there are four models of regional floristic migration and exchange,i.e.,into tibet,out of tibet,out of India and into/out of Africa.(3)Plant fossils evidence the asynchronous formation histories for different parts of the tibetan *** most of the Paleogene,there was a wide east-west trending valley with a subtropical climate in central tibet bounded by high(>4 km)mountain systems,but that by the early Oligocene the modern high plateau had begun to form by the rise of the valley *** reconstructions using radiometrically-dated plant fossil assemblages in southeastern tibet show that by the earliest Oligocene southeastern tibet(including the Hengduan Mountains)had reached its present elevation.(4)the coevolution between vegetation,landform and paleoenvironment is evidenced by fossil records from what is now the central tibetan *** the Paleocene to Pliocene,plant diversity transformed from that of tropical,to subtropical forests,through warm to cool temperate woodland and eventually to deciduous shrubland in response to landscape evolution from a seas

关键词： tibetan Plateau Cenozoic Paleobotany Flora Central valley Biodiversity