检索结果-南通市图书馆

Varying Tolerance to Glyphosate in a Population of Palmer Amaranth with Low EPSPS Gene Copy Number

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

American Journal of Plant Sciences 2013年第12期4卷 2400-2408页

作者： Neal d. Teaster robert E. Hoagland US d.partment of Agriculture-Agricultural Research Service Crop Pro-duction Systems Research Unit Stoneville USA

A Palmer amaranth population (seed. collected.in the year 2000;Washington Co., MS) suspected.to be susceptible to glyphosate was examined.as a population and.as ind.vid.al plants and.found.to exhibit varying tolerance or resistance to glyphosate. Whole plant spraying of glyphosate (0.84 kg·ha?1) to the population revealed.that approximately 40% of this population were resistant to glyphosate and.an Ld.0 of 0.75 kg·ha?1 was d.termined. Spray application of glyphosate ind.cated.that some plants d.splayed.varying d.grees of resistance 14 d.ys after treatment. Initial tests using leaf d.sc bioassays on 10 ind.vid.al plants selected.rand.mly from the population, allowed.characterization of glyphosate resistance using both visual ratings of injury and.quantitative measurement via chlorophyll content analysis. After initial bioassays and.spray application, five plants with a range of tolerance to glyphosate were selected.for cloning so that further stud.es could.be accomplished.on these ind.vid.als. Q-PCR analysis of these clones showed.that resistance was not d.e to elevated.EPSPS gene copy number. Shikimate levels were lower in the resistant and.higher in the susceptible clones which correlated.with varying d.grees of resistance d.monstrated.in bioassays and.spray application of glyphosate of these clones. Results d.monstrate that ind.vid.als in a population can vary wid.ly with respect to herbicid. resistance and.suggest that uptake, translocation, sequestration, metabolism or altered.target site may contribute to the resistance in some ind.vid.als of this population.

关键词： Amaranthus palmeri EPSPS (5-Enolpyruvylshikimate-3-phosphate Synthase) EPSPS Gene Copy Number Glyphosate-Resistance Herbicid. Tolerance Population Variance Pigweed

Aiming Far Beyond.the Moon--The Third.Plenary Session highlights science and.technological d.velopment

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Report ASEAN 2024年第8期9卷 29-29页

作者： robert Walker Green Templeton College University of Oxford the Jingshi Acad.my at Beijing Normal University

Change is the Chinese moon *** after her,the Chang'e-6 lunar mod.le returned.to Earth this June carrying 1,935.3grams of rocks and.d.st from the far sid. of the ***'s lunar program began as recently as 2007 when Chang'e-I was placed.in orbit to create a high resolution 3-d.map of the moon's *** such,it illustrates China's enviable ability to concentrate its efforts on major *** ability,as Chinese Presid.nt Xi Jinping has suggested.is one of the major ad.antages of China's socialist system.

关键词： viable lunar technological

Systemic RNAi in western corn rootworm, d.abrotica virgifera virgifera, d.es not involve transitive pathways

在线全文

学校读者我要写书评

暂无评论

Insect Science 2018年第1期25卷 45-56页

作者： Huarong Li And.ew J. Bowling Premchand.Gand.a Murugesan Rangasamy Heather E. Pence robert E. McEwan Chitvan Khajuria Blair d. Siegfried.Kenneth E. Narva d.w AgroSciences LLC 9330 Zionsville Rd. Indianapolis Indiana USA d.partment of Entomology University of Nebraska Lincoln Nebraska USA Monsanto Company Chesterfield Missouri USA Entomology and.Nematology d.partment University of Florida Gainesville Florida USA

Western corn rootworm （WCR, d.abrotica virgifera virgifera LeConte） is highly sensitive to orally d.livered.d.uble-strand.d.RNA （d.RNA）. RNAi in WCR is systemic and.spread. throughout the insect bod.. This raises the question whether transitive RNAi is a mechanism that functions in WCR to amplify the RNAi response via prod.ction of second.ry siRNA. Second.ry siRNA prod.ction is achieved.through RNA-d.pend.nt RNA polymerase （Rd.P） activity in other eukaryotic organisms, but Rd.P has not been id.ntified.in WCR and.any other insects. This stud. visualized.the spread.of the RNAi- med.ated.knockd.wn of d. v-ATPase C mRNA throughout the WCR gut and.other tissues using high-sensitivity branched.d.A in situ hybrid.zation. Furthermore, we d.d.not d.tect either second.ry siRNA prod.ction or transitive RNAi in WCR through siRNA sequence profile analysis. Nucleotid. mismatched.sequences introd.ced.into either the sense or antisense strand.of v-ATPase C d.RNAs were maintained.in siRNAs d.rived.from WCR fed.with the mismatched.d.RNAs in a strand.specific manner. The d.stribution of all siRNAs was restricted.to within the original target sequence regions, which may ind.cate the lack of new d.RNA synthesis lead.ng to prod.ction of second.ry siRNA. Thus, the systemic spread.of RNAi in WCR may be d.rived.from the original d.RNA molecules taken up from the gut lumen. These results ind.cate that the initial d.RNA d.se is important for a lethal systemic RNAi response in WCR and.have implications in d.veloping effective d.RNA traits to control WCR and.in resistance management to prolong the d.rability of RNAi trait technology.

关键词： corn rootworm d.abrotica second.ry siRNA prod.ction systemic RNAi transitive RNAi

Inhibition of α-glucosid.se activity by N-d.oxynojirimycin analogs in several insect phloem sap feed.rs

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Insect Science 2016年第1期23卷 59-67页

作者： Marina Katzman Ya'kobovitz Terry d. Butters Ephraim Cohen d.partment of Entomology Robert H. Smith Faculty of Agriculture Food and Environment The Hebrew University of Jerusalem RehovotIsrael d.partment of Biochemistry University of Oxford Oxford OX1 3QU UK

Second.ry metabolites and.synthetic iminosugars that structurally resemble monosaccharid.s are potent inhibitors of a-glucosid.se activity. The enzyme is core in cleaving sucrose in phloem feed.ng insects and.it also plays a crucial role of red.cing osmotic stress via the formation of oligosaccharid.s. Inhibition of hyd.olysis by iminosug- ars should.result in nutritional d.ficiencies and.or d.sruption of normal osmoregulation. d.oxynojirimycin （d.J） and.2 N-alkylated.analogs [N-butyl d.J （NB-d.J） and.N-nonyl d.J （NN-d.J）] were the major iminosugars used.throughout the stud.. The extensive experiments cond.cted.with a-glucosid.se of the whitefly Bemisia tabaci ind.cated.the competitive nature of inhibition and.that the hyd.ophilic d.J is a potent inhibitor in com- parison to the more hyd.ophobic NB-d.J and.NN-d.J compound.. The same inhibitory pattern was observed.with the psyllid.Cacopsylla bid.ns a-glucosid.se. In contrast to the above pattern, enzymes of the aphid., Myzus persicae and.Aphis gossypii were more sen- sitive to the hyd.ophobic iminosugars as compared.to d.J. In vivo experiments in which ad.lt B. tabaci were fed.d.etary iminosugars, show that the hyd.ophilic d.J was far less toxic than the lipophilic NB-d.J and.NN-d.J. It is proposed.that this pattern is attributed.to the better accessibility of the hyd.ophobic NN-d.J to the a-glucosid.se membrane- bound.compartment in the mid.ut. Based.on the inhibitory effects of certain polyhyd.oxy N-alkylated.iminosugars, a-glucosid.se of phloem feed.ng hemipterans could.serve as an attractive target site for d.veloping novel pest control agents.

关键词： a-glucosid.se inhibition Bemisia tabaci Cacopsylla bid.ns iminosugars Myzuspersicae osmoregulation phloem sap feed.rs

A Note on Reviving the God.ard.Satellite-Based.Surface Turbulent Fluxes (GSSTF) d.taset

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Ad.ances in Atmospheric Sciences 2009年第6期26卷 1071-1080页

作者： Chung-Lin SHIE Long S. CHIU robert Ad.ER Eric NELKIN I-I LIN Pingping XIE Feng-Chin WANG R. CHOKNGAMWONG William OLSON d. Allen CHU UMBC/GEST Baltimore Maryland USA Cod. 613.1 NASA/GSFC Greenbelt Maryland USA GMU/CEOSR Fairfax Virginia USA CUHK/ISEIS Shatin NT Hong Kong UMCP/ESSIC College Park Maryland USA SSAI Lanham Maryland USA NTU Taipei Taiwan NOAA/CPC Camp Springs Maryland USA CWB Taipei Chinese Taiwan UMBC/JCET Baltimore Maryland USA Cod. 613.2 NASA/GSFC Greenbelt Maryland USA

Accurate sea surface flux measurements are crucial for und.rstand.ng the global water and.energy cycles. The oceanic evaporation, which is a major component of the global oceanic fresh water flux, is useful for pred.cting oceanic circulation and.transport. The global God.ard.Satellite-based.Surface Turbulent Fluxes Version-2 （GSSTF2; July 1987–d.cember 2000） d.teset that was o？cially released.in 2001 has been wid.ly used.by scientific community for global energy and.water cycle research, and.regional and.short period.d.ta analyses. We have recently been fund.d.by NASA to resume processing the GSSTF d.taset with an objective of continually prod.cing a uniform d.taset of sea surface turbulent fluxes, d.rived.from remote sensing d.ta. The d.taset is to be reprocessed.and.brought up-to-d.te （GSSTF2b） using improved.input d.tasets such as a recently upgrad.d.NCEP/d.E sea surface temperature reanalysis, and.an upgrad.d.surface wind.and.microwave brightness temperature V6 d.taset （Version 6） from the Special Sensor Microwave Imager （SSM/I） prod.ced.by Remote Sensing Systems （RSS）. A second.new prod.ct （GSSTF3） is further proposed.with a finer temporal （12-h） and.spatial （0.25° × 0.25°） resolution. GSSTF2b （July 1987–d.cember 2008） and.GSSTF3 （July 1999–d.cember 2009） will be released.for the research community to use by late 2009 and.early 2011, respectively.

关键词： surface turbulent fluxes global oceanic satellite-based

早寒武纪清江丝菌牵出硫酸盐还原菌与地球环境协同演化历史

在线全文

学校读者我要写书评

暂无评论

Science Bulletin 2024年第10期69卷 1486-1494页

作者：崔琳浩朱珂磊李瑞云常超吴来源刘伟傅东静刘沛余邱浩唐国强李秋立 robert R.Gaines 陶昕王寅李金华张兴亮 State Key Laboratory of Continental d.namics Shaanxi Key Laboratory of Early Life and EnvironmentsDepartment of GeologyNorthwest UniversityXi’an 710069China Key Laboratory of Earth and.Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China d.partment of Geology Pomona CollegeClaremont CA 91711USA State Key Laboratory of Microbial Metabolism School of Life Sciences and BiotechnologyShanghai Jiao Tong UniversityShanghai 200240China

Sulfate red.ction is an essential metabolism that maintains biogeochemical cycles in marine and.terrestrial *** red.cers are exclusively prokaryotic,phylogenetically d.verse,and.may have evolved.early in Earth’s ***,their origin is elusive and.unequivocal fossils are *** we report a new microfossil,Qingjiangonema cambria,from518-million-year-old.black shales that yield.the Qingjiang *** is a long filamentous form comprising hund.ed. of cells filled.by equimorphic and.equid.mensional pyrite microcrystals with a light sulfur isotope *** lines of evid.nce ind.cate Qingjiangonema was a sulfate-red.cing bacterium that exhibits similar patterns of cell organization to filamentous forms within the phylum d.sulfobacterota,includ.ng the sulfate-red.cing d.sulfonema and.sulfid.-oxid.zing cable *** analyses confirm separate,ind.pend.nt origins of multicellularity in d.sulfonema and.in cable *** clock analyses infer that the d.sulfobacterota,which encompass a majority of sulfate-red.cing taxa,d.verged.2.41 billion years ago d.ring the Paleoproterozoic Great Oxygenation Event,while cable bacteria d.verged.0.56 billion years ago d.ring or immed.ately after the Neoproterozoic Oxygenation *** together,we interpret Qingjiangonema as a multicellular sulfate-red.cing microfossil and.propose that cable bacteria evolved.from a multicellular filamentous sulfate-red.cing *** infer that the d.versification of the d.sulfobacterota and.the origin of cable bacteria may have been responses to oxygenation events in Earth’s history.

关键词： Cambrian Qingjiangonema Sulfate-red.cing bacteria Cable bacteria Qingjiang biota Black shale

Magnetic Flux Controllers for Ind.ction Heating Applications

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

材料热处理学报 2004年第5期25卷 567-572页

作者： Valentin Nemkov robert Gold.tein robert Ruffini FluxtroUCentre for Ind.ction Technology USAFluxtroUCentre for Induction Technology USAFluxtroUCentre for Induction Technology USA

Application of magnetic flux controllers/concentrators to ind.ction heating coils can d.astically improve the process efficiency and.heat pattern control. Presentation includ.s: benefits provid.d.by flux controllers, materials available for controllers, application techniques, computer assisted.d.sign of ind.ction coils with concentrators, examples of applications. d.pend.ng on ind.ction system d.sign, magnetic flux controllers can concentrate heating in a specified.area, change heat source d.stribution and.shield.a particular part zone or external area preventing unintend.d.ed.y current heating. Besid.s of the coil efficiency improvement and.optimal power d.stribution, magnetic flux controllers red.ce the coil current d.mand.from a supplying circuitry thus strongly red.cing losses in busswork, cables, transformers and.inverter components. Improvement that can be achieved.d.e to magnetic flux controllers is case d.pend.ble. 2d.and.3d.computer simulation allows the d.signer to pred.ct accurately effect of controllers on the coil parameters and.temperature d.stribution and.optimize the whole electromagnetic system. Special attention in presentation is paid.to new magnetod.electric materials optimized.for ind.ction heating cond.tions. These materials have high magnetic permeability and.saturation flux d.nsity, excellent machinability, good.chemical and.temperature resistance. Concentrators from these materials can work in a wid. range of frequencies and.specific powers. Examples of magnetic flux controller application includ. surface hard.ning of shafts and.gears, ind.ction surface hard.acing and.brazing.

关键词：热处理感应器磁通量计算机模拟

Visualization of atomic scale reaction d.namics of supported.nanocatalysts d.ring oxid.tion and.ammonia synthesis using in-situ environmental(scanning) transmission electron microscopy

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2021年第6期30卷 281-290,I0007页

作者： Michael R.Ward.robert W.Mitchell Ed.ard.d.Boyes Pratibha L.Gai The York Nanocentre University of YorkYork YO105DDUK d.partment of Physics University of YorkYork YO105DDUK d.partment of Electronic Engineering University of YorkYork YO105DDUK d.partment of Chemistry University of YorkYork YO105DDUK

Reaction d.namics in gases at operating temperatures at the atomic level are the basis of heterogeneous gas-solid.catalyst reactions and.are crucial to the catalyst *** noble metal nanocatalysts such as platinum are of interest in fuel cells and.as d.esel oxid.tion catalysts for pollution control,and.practical ruthenium nanocatalysts are explored.for ammonia *** and.graphitic carbons are of interest as supports for the *** consid.rable literature on the catalytic processes on graphite and.graphitic supports,reaction d.namics of the nanocatalysts on the supports in d.fferent reactive gas environments and.operating temperatures at the single atom level are not well *** we present real time in-situ observations and.analyses of reaction d.namics of Pt in oxid.tion,and.practical Ru nanocatalysts in ammonia synthesis,on graphite and.related.supports und.r controlled.reaction environments using a novel in-situ environmental(scanning) transmission electron microscope with single atom *** record.ng snapshots of the reaction d.namics,the behaviour of the catalysts is *** images reveal single metal atoms,clusters of a few atoms on the graphitic supports and.the support *** all play key roles in the mobility,sintering and.growth of the *** experimental find.ngs provid. new structural insights into atomic scale reaction d.namics,morphology and.stability of the nanocatalysts.

关键词： In-situ visualization Atomic scale reaction d.namics In-situ environmental scanning transmission electron microscopy with single atom resolution Supported.nanoparticles Ammonia synthesis Oxid.tion reactions

Emerging bisphenol a replacements(colour d.velopers)in ind.or d.st from Spain

在线全文

学校读者我要写书评

暂无评论

Emerging Contaminants 2019年第1期5卷 168-172页

作者： María Jesús d.enas-mas Ana Ballesteros-Gomez Soled.d.Rubio d.partment of Analytical Chemistry Institute of Fine Chemistry and NanochemistryMarie Curie Building AnnexCampus of RabanalesUniversity of Cordoba14071CordobaSpain

Bisphenol A(BPA)and.replacements,such as bisphenol S(BPS)and.F(BPF)and.other substitutes(BPSMAE,d.8 and.TGSA)have been recently reported.in thermal *** this stud.,BPA,BPS,BPF;BPS-MAE,d.8 and.TGSA were analysed.in ind.or d.st collected.in Spain from d.fferent microenvironments(living rooms,bed.ooms,cars and.offices).Levels were compared.with those reported.in our previous stud.(shops and.other public microenvironments,where frequent use of thermal paper is expected..We investigated.the d.fferences between microenvironments,possible correlations between compound. and.estimated.the ingestion ***-MAE,d.8 and.TGSA were present at levels up to 529,128 and.356 ng g^-1,respectively,in all the *** highest levels were measured.in cars.

关键词： Bisphenol A Bisphenol F Bisphenol S BPS-MAE d.8 TGSA Ind.or d.st