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Gully erosion spatial modelling: Role of machine learning algorithms in selection of the best controlling factors and modelling process

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Geoscience Frontiers 2020年第6期11卷 2207-2219页

作者： Hamid Reza Pourghasemi Nitheshnirmal Sadhasivam Narges Kariminejad Adrian l.collins Department of Natural Resources and Environmental Engineering College of AgricultureShiraz UniversityShirazIran Department of Geography School of Earth ScienceBharathidasan UniversityTiruchirappalli620024Tamil NaduIndia Department of Watershed and Arid Zone Management Gorgan University of Agricultural Sciences and Natural ResourcesGorganIran Sustainable Agriculture Sciences Rothamsted ResearchNorth WykeOkehamptonDevonEX202SBUK

This investigation assessed the efficacy of 10 widely used machine learning algorithms(MlA)comprising the least absolute shrinkage and selection operator(lASSO),generalized linear model(GlM),stepwise generalized linear model(SGlM),elastic net(ENET),partial least square(PlS),ridge regression,support vector machine(SVM),classification and regression trees(CART),bagged CART,and random forest(RF)for gully erosion susceptibility mapping(GESM)in *** location of 462 previously existing gully erosion sites were mapped through widespread field investigations,of which 70%(323)and 30%(139)of observations were arbitrarily divided for algorithm calibration and *** controlling factors for gully erosion,namely,soil texture,annual mean rainfall,digital elevation model(DEM),drainage density,slope,lithology,topographic wetness index(TWI),distance from rivers,aspect,distance from roads,plan curvature,and profile curvature were ranked in terms of their importance using each *** MlA were compared using a training dataset for gully erosion and statistical measures such as RMSE(root mean square error),MAE(mean absolute error),and *** on the comparisons among MlA,the RF algorithm exhibited the minimum RMSE and MAE and the maximum value of R-squared,and was therefore selected as the best *** variable importance evaluation using the RF model revealed that distance from rivers had the highest significance in influencing the occurrence of gully erosion whereas plan curvature had the least *** to the GESM generated using RF,most of the study area is predicted to have a low(53.72%)or moderate(29.65%)susceptibility to gully erosion,whereas only a small area is identified to have a high(12.56%)or very high(4.07%)*** outcome generated by RF model is validated using the ROC(Receiver Operating Characteristics)curve approach,which returned an area under the curve(AUC)of 0.985,proving the excellent forecasting ability of the model

关键词： Machine learning algorithm Gully erosion Random forest Controlling factors Variable importance

Cool Deformation Properties of an X70 Industrial Steel

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Journal of Iron and Steel Research International 2011年第S1期18卷 681-684页

作者： S.H.Mousavi Anijdan S.Nafisi l.collins Department of Mining and Materials Engineering McGill University3610 University StreetMontréalQuébecCanadaH3A 2B2 Evraz Inc.NA ReginaSaskatchewan

In the past few years cool deformation research at McGill *** been centered on experimental *** this work an X70 industrial grade is examined by means of torsion *** a full hot rolling physical simulation,three levels of cool deformation strain,0.06,0.12,and 0.2 were applied at 400 o C and the subsequent strength were measured at room temperature;and the results were compared with the no-cool deformation *** effect of cooling rate after the finishing stage on the cool deformed microstructure and properties was also *** results show that by applying even a small amount of deformation,the yield point increases remarkably.

关键词： cool deformation X70 steel mechanical property

Developing a sustainable strategy to conserve reservoir marginal landscapes

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National Science Review 2018年第1期5卷 10-14页

作者： Qiang Tang Bojie Fu Adrian l.collins Anbang Wen Xiubin He Yuhai Bao Key laboratory of Mountain Surface Processes and Ecological Regulation Institute of Mountain Hazards and Environment Chinese Academy of Sciences State Key laboratory of Urban and Regional Ecology Research Center for Eco-Environmental SciencesChinese Academy of Sciences

China has accelerated its pace in building dams to meet growing demands in energy consumption,as well as to alleviate air pollution resulting from fossil fuel emissions and to mitigate global climate change *** rivers in southwestern China(*** Jinsha,Yalong,Dadu,Wu,Nu,lancang and upper Yangtze rivers)have primarily been targeted as major basins for hydropower development,where cascade dams have been constructed or are *** them,the Three Gorges Dam is the world’s largest hydropower project

关键词： Developing a sustainable strategy to conserve reservoir marginal landscapes

Post-weaning and whole-of-life performance of pigs is determined by live weight at weaning and the complexity of the diet fed after weaning

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Animal Nutrition 2017年第4期3卷 372-379页

作者： Cherie l.collins John R.Pluske Rebecca S.Morrison Trevor N.McDonald Robert J.Smits David J.Henman Ingunn Stensland Frank R.Dunshea Rivalea Australia Pty ltd School of Veterinary and life Sciences Murdoch University Faculty of Veterinary and Agricultural Sciences The University of Melbourne

The production performance and financial outcomes associated with weaner diet complexity for pigs of different weight classes at weaning were examined in this experiment. A total of 720 weaner pigs(360 entire males and 360 females) were selected at weaning(27 ± 3 d) and allocated to pens of 10 based on individual weaning weight(light weaning weight: pigs below 6.5 kg; medium weaning weight: 6.5 to8 kg; heavy weaning weight: above 8.5 kg). Pens were then allocated in a 3 x 2 x 2 factorial arrangement of treatments with the respective factors being weaning weight(heavy, medium and light; H, M and l,respectively), weaner diet complexity(high complexity/cost, HC; low complexity/cost, lC), and gender(male and female). Common diets were fed to both treatment groups during the final 4 weeks of the weaner period(a period of 39 days). In the first 6 d after weaning, pigs offered the HC diets gained weight faster and used feed more efficiently than those offered the lC diets(P = 0.031). Pigs fed a HC diet after weaning tended to be heavier at the sale live weight of 123 d of age compared with pigs fed the lC diet(P = 0.056). There were no other main effects of the feeding program on growth performance through to slaughter. Weaning weight had a profound influence on lifetime growth performance and weight at 123 d of age, with H pigs at weaning increasing their weight advantage over the M and l pigs(101.3,97.1, 89.6 kg respectively, P lyses suggested there was a minimal benefit in terms of cost per unit live weight gain over lifetime when pigs were offered a HC feeding program to l,with a lower feed cost/kg gain. The results from this investigation confirm the impact of weaning weight on lifetime growth performance, and suggest that a HC feeding program should be focused on l weaner pigs(i.e., weaning weight less than 6.5 kg at 27 d of age) in order to maximise financial returns.

关键词： Pigs Performance Diet complexity Weaning weight Carcass characteristics Cost benefit analyses

live-Cell Imaging of Dual-labeled Golgi Stacks in Tobacco BY-2 Cells Reveals Similar Behaviors for Different Cisternae during Movement and Brefeldin A Treatment

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Molecular Plant 2011年第5期4卷 896-908页

作者： stephanie l. Madison Andreas Nebenfuhr Department of Biochemistry and Cellular and Molecular Biology University of Tennessee Knoxville TN 37996-0840 USA

In plant cells, the Golgi apparatus consists of numerous stacks that, in turn, are composed of several flattened cisternae with a clear cis-to-trans polarity. During normal functioning within living cells, this unusual organelle displays a wide range of dynamic behaviors such as whole stack motility, constant membrane flux through the cisternae, and Golgi enzyme recycling through the ER. In order to further investigate various aspects of Golgi stack dynamics and integrity, we co-expressed pairs of established Golgi markers in tobacco BY-2 cells to distinguish sub-compartments of the Golgi during monensin treatments, movement, and brefeldin A （BFA）-induced disassembly. A combination of cis and trans markers revealed that Golgi stacks remain intact as they move through the cytoplasm. The Golgi stack orientation during these movements showed a slight preference for the cis side moving ahead, but trans cisternae were also found at the leading edge. During BFA treatments, the different sub-compartments of about half of the observed stacks fused with the ER sequentially; however, no consistent order could be detected. In contrast, the ionophore monensin resulted in swelling of trans cisternae while medial and particularly cis cisternae were mostly unaffected. Our results thus demonstrate a re- markable equivalence of the different cisternae with respect to movement and BFA-induced fusion with the ER. In addi- tion, we propose that a combination of dual-label fluorescence microscopy and drug treatments can provide a simple alternative approach to the determination of protein localization to specific Golgi sub-compartments.

关键词： Golgi apparatus Golgi stack integrity brefeldin A monensin tobacco BY-2 cells live-cell imaging.

Increased working voltage of hexamine-coated porous carbon for supercapacitors

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Science Bulletin 2015年第18期60卷 1587-1597页

作者： stephanie l.Candelaria Guozhong Cao Department of Materials Science and Engineering University of Washington

Highly porous carbon, both unmodified and hexamine-coated on the pore surfaces, is tested at high working voltages in organic electrolyte for supercapacitors in order to enhance the energy density and power ***–gel processing allows for excellent control of the porous structure and chemical composition of carbon,resulting in a material with high surface area and a low level of impurities. This porous carbon can be modified using a simple solution-based method to enhance capacitance. Increasing the working voltage from 2.0 to 3.0 V significantly improves performance for both unmodified and hexamine-coated carbon. The energy density and power density increase at higher working voltage, and under certain conditions, the capacitance increases as *** stability is also investigated, with hexamine-coated carbon retaining more of its initial capacitance than unmodified carbon at all working voltages.

关键词： Supercapacitor High voltage Porouscarbon Hexamine Surface modification Nitrogen

Immune dysfunction in acute alcoholic hepatitis

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World Journal of Gastroenterology 2015年第42期21卷 11904-11913页

作者： Ashwin D Dhanda Peter l.collins School of Clinical Sciences University of Bristol NIHR Academic Clinical lecturer in Hepatology Institute of Translational and Stratified Medicine Plymouth University Peninsula Schools of Medicine and Dentistry South West liver Unit Plymouth Hospitals NHS Trust Department of liver Medicine University Hospitals Bristol NHS Foundation Trust

Acute alcoholic hepatitis(AAH) is a serious complication of alcohol misuse and has high short term mortality. It is a clinical syndrome characterised by jaundice and coagulopathy in a patient with a history of recent heavy alcohol use and is associated with profound immune dysfunction with a primed but ineffective immune response against pathogens. Here, we review the current knowledge of the pathogenesis and immune defects of AAH and identify areas requiring further study. Alcohol activates the immune system primarily through the disruption of gut tight junction integrity allowing the escape of pathogenassociated molecular particles(PAMPs) into the portal venous system. PAMPs stimulate cells expressing toll-like receptors(mainly myeloid derived cells) and initiate a network of intercellular signalling by secretion of many soluble mediators including cytokines and chemokines. The latter coordinates the infiltration of neutrophils, monocytes and T cells and results in hepatic stellate cell activation, cellular damage and hepatocyte death by necrosis or apoptosis. On the converse of this immune activation is the growing evidence of impaired microbial defence. Neutrophils have reduced phagocytic capacity and oxidative burst and there is recent evidence that T cell exhaustion plays a role in this.

关键词： Alcoholic hepatitis Alcoholic liver disease Toll-l

leaf size versus leaf numbertradeoffs in dioecious angiosperms

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Journal of Plant Ecology 2013年第1期6卷 29-35页

作者： stephanie l.Scott lonnie W.Aarssen Department of Biology Queen’s UniversityKingstonOntarioCanada K7L 3N6

Aims We explore the possible role of leaf size/number trade-offs for the interpretation of leaf size dimorphism in dioecious plant *** Total above-ground biomass(both male and female)for three herbaceous dioecious species and individual shoots(from both male and female plants)for three woody dioecious species were sampled to record individual leaf dry mass,number of leaves,dry mass of residual above-ground tissue(all remaining non-leaf biomass),number of flowers/inflorescences(for herbaceous species)and number of *** Findings For two out of three woody species and two out of three herbaceous species examined,male plants produced smaller leaves but with higher leafing intensity—*** leaves per unit of supporting(residual)shoot tissue or plant body mass—compared with *** and female plants,however,did not differ in shoot or plant body mass or branching *** interpret these results as possible evidence for a dimorphic leaf deployment strategy that promotes both male and female function,*** male plants,capacity as a pollen donor may be favored by selection for a broadly spaced floral display,hence favoring relatively high leafing intensity because this provides more numerous axillary meristems that can be deployed for flowering,thus requiring a relatively small leaf as a *** one herbaceous species,higher leafing intensity in males was associated with greater flower production than in *** contrast,in female plants,selection favors a relatively large leaf,we propose,because this promotes greater capacity for localized photosynthate production,thus supporting the locally high energetic cost of axillary fruit and seed development,which in turn requires a relatively low leafing intensity as a trade-off.

关键词： bud bank leaf dimorphism leafing intensity dioecy

CdS quantum dot aerogels for photocatalytic hydrogen evolution

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Nano Research 2024年第12期17卷 10292-10301页

作者： Vinicius Alevato Daniel Streater Cole Premtaj Jier Huang stephanie l.Brock Department of Chemistry Wayne State UniversityDetroitMI 48202USA Department of Chemistry Marquette UniversityMilwaukeeWI 53201USA Department of Chemistry&Shiller Institute for Integrated Science and Society Boston CollegeBostonMA 02467USA

CdS quantum dots(QDs)have been extensively studied as photocatalysts and sensitizers for visible-light-driven water ***,their efficiencies are limited by the need to accumulate sufficient redox equivalents to produce_(H2)and consequent photocorrosion associated with slow hole-transfer *** address these limitations,we report the formation of CdS QD assemblies(aerogels,AGs)capable of facilitating energy/charge transport between individual QDs,and evaluate their performance as photocatalysts for hydrogen evolution as a function of structure,wurtzite(w-)***(zb-),and different annealing *** formation of AGs from QDs resulted in increased rates of_(H2)production under visible light illumination:from 1458(QD)to 6650(AG)μmol_(H2)·h^(-1)·g^(-1)on zbCdS and from 1221(QD)to 3325(AG)μmol_(H2)·h^(-1)·g^(-1)on *** is attributed to exciton delocalization between adjacent QDs facilitating charge/energy *** processing of CdS AGs up to 250℃ improved their activity,increasing the degree of exciton delocalization,while annealing them to 300℃ caused sintering of the primary QD particles within the AGs and a decrease in activity associated with loss in surface *** best photocatalyst,zbCdS AG annealed at 250℃,had an average_(H2)production rate of 13,604±2017μmol_(H2)·h^(-1)·g^(-1),an apparent quantum yield of 2.8%at 425±12.5 nm,and was stable for 2 h before beginning to deactivate due to *** study confirms the potential of CdS AGs as matrixes for the design of more active and stable composite photocatalysts for water splitting.

关键词： sol-gel chemistry photocorrosion apparent quantum yield wurtzite zinc blende