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Bioacoustic variation of swim.ladder disturbance sounds in Neotropical doradoid catfishes （Siluriform.s： Doradidae, Auchenipteridae）： Potential m.rphological correlates

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Current Zoology 2012年第1期58卷 171-188页

作者： Kaatz, Ingrid m. Stewart, Donald j. Departm.nt of Environm.ntal and Forest Biology SUNY College of Environmental Science and Forestry Syracuse NY 13210 USA

Swim.ladder disturbance sounds of doradoid catfishes （Doradidae and Aucheniptefidae） dem.nstrated striking waveform.and spectrographic variation. We surveyed sounds of 25 doradoid species in 20 genera com.aring these to sounds of four vocal outgroup catfish fam.lies. Sounds were either continuous waveform. （lacking interpulses） or pulsed （groups of pulses repeated at fixed tem.oral intervals）. This is the first evidence for swim.ladder calls with fixed interpulse patterns in catfishes. Vocal m.chanism.com.onents that were sim.lar between doradids and auchenipterids included： swim.ladder shape, swim.ladder dim.nsions and sonic m.scle-som.tic index. m.rphological traits that showed variation am.ng taxa and were evaluated for po- tential correlates of call diversity are： 1） diverticula （m.rginal outpocketings of the swim.ladder with no connection to inner ear） and 2） elastic spring apparatus m.illerian ram. （ESA-m.）. Within the doradid subfam.lies and within the Auchenipteridae m.st species differed significantly in dom.nant frequency with frequency ranges overlapping to som. extent for m.st. Doradid swim. bladder diverticula did not explain dom.nant frequency variation within the doradoid superfam.ly. Som. doradids with conical ESA-m. had the highest dom.nant frequency sounds. Auchenipterids included both relatively lower and higher dom.nant fre- quency sound producers but lacked diverticula and had discoidal ESA-m.. Com.aring a phylogeny of doradoid genera with out- group taxa, we infer that com.lex diverticula and conical ESA-m. are derived characters within the Doradidae. Species repre- senting outgroup fam.lies produced either continuous lower dom.nant frequency sounds （aspredinids, m.chokids and pseudopim.lodids） or pulsed higher dom.nant frequency sounds （pim.lodids） [Current Zoology 58 （1）： 171-188, 2012].

关键词： Catfishes Com.unication Signal evolution Vocal m.chanism.

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Specifications of Targeting Heterochrom.tin m.difications in Plants

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m.lecular Plant 2018年第3期11卷 381-387页

作者： j.red m. Wendte Robert j. Schm.tz Departm.nt of Genetics University of Georgia Athens GA 30602 USA

Plants encode a diverse repertoire of DNA m.thyltransferases that have specialized to target cytosines for m.thylation in specific sequence contexts. These include the de novo m.thyltransferase, DOm.INS REARRANGED m.THYLTRANSFERASE 2 （DRm.）, which m.thylates cytosines in all sequence contexts through an RNA-guided process, the CHROm.m.THYLASES （Cm.s）, which m.thylate CHH and CHG cytosines （where H is A, T, or C）, and m.THYLTRANSFERASE 1 （m.T1）, which m.intains m.thylation of sym.etrical CG contexts. In this review, we discuss the sequence specificities and targeting of each of these pathways. In particular, we highlight recent studies that indicate Cm.s preferentially target CWG or CWA/CAW m.tifs （where W is A or T）, and discuss how self-reinforcing feedback loops between DNA m.thyltransferases and histone m.difications characteristic of heterochrom.tin specify targeting. Finally, the initiating events that lead to gene body m.thylation are discussed as a m.del illustrating how interde- pendent targeting of different silencing pathways can potentiate the establishm.nt of off-target epialleles.

关键词： heterochrom.tin DNA m.thylation gene body m.thylation epiallele DNA m.thyltransferase,chrom.m.thylase

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Structural and functional roles of ether lipids

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Protein & Cell 2018年第2期9卷 196-206页

作者： j.hn m. Dean Irfan j. Lodhi Division of Endocrinology Metabolism and Lipid Research Department of Medicine Washington University School of Medicine Saint Louis MO 63110 USA

Ether lipids, such as plasm.logens, are peroxisom.- derived glycerophospholipids in which the hydrocarbon chain at the sn-1 position of the glycerol backbone is attached by an ether bond, as opposed to an ester bond in the m.re com.on diacyl phospholipids. This seem. ingly sim.le biochem.cal change has profound structural and functional im.lications. Notably, the tendency of ether lipids to form.non-lam.llar inverted hexagonal structures in m.del m.m.ranes suggests that they have a role in facilitating m.m.rane fusion processes. Ether lipids are also im.ortant for the organization and stability of lipid raft m.crodom.ins, cholesterol-rich m.m.rane regions involved in cellular signaling. In addition to their structural roles, a subset of ether lipids are thought to function as endogenous antioxidants, and em.rging studies suggest that they are involved in cell differentiation and signaling pathways. Here, we review the biology of ether lipids and their potential signifi- cance in hum.n disorders, including neurological diseases, cancer, and m.tabolic disorders.

关键词： ether lipids plasm.logen phospholipid peroxisom.s cancer m.tabolic disorders

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Differences in Physiological Age Affect Diagnosis of Nitrogen Deficiencies in Cornfields

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Pedosphere 2008年第5期18卷 545-553页

作者： j. ZHANG A. m. BLACKm.R T. m. BLACKm.R Statistical Consulting Center Wright State University 3640 Colonel Glenn Highway Dayton Ohio 45435 （USA）. Departm.nt of Agronom. Iowa State University Ames Iowa 50011 （USA） Iowa Soybean Association 4554 114th Street Urbandale Iowa 50322 （USA）

m.ny studies have shown that chlorophyll m.ter readings （Cm.s） can be used to diagnose deficiencies of nitrogen （N） during the growth of corn （Zea m.ys L.） in sm.ll-plot trials, but there is need to address additional problem. encountered when diagnoses are m.de in fields of the size m.naged in production agriculture. A noteworthy difference between sm.llplot trials and production agriculture is the extent to which the effects of N are confounded with the effects of other factors such as tillage, landscape, soil organic m.tter and m.isture content. We illustrate how som. of these factors can cause differences in the physiological age of plants and introduce errors in the diagnoses of N deficiencies. We suggest m.thods （m.asuring the height to the youngest leaf collar and assigning leaf num.ers by using the first leaf with pubescence and the ear leaf as references to identify growth stages） for m.nim.zing these errors. The sim.lified m.thod of growth stage identification can be used to select appropriate plants and leaves for m.king diagnoses in fields and to distinguish the effects of N from.the effects of other factors that influence plant growth.

关键词： chlorophyll corn (Zea m.ys L.) nitrogen deficiency physiological age

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Surface Characterisation of Silicon Based m.m.

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Chem.cal Research in Chinese Universities 2004年第4期20卷 407-410页

作者： LI j. CUI Z m. A. Baker The Surface Analysis Laboratory School of Engineering University of SurreyRutherford Appleton LaboratoryThe Surface Analysis Laboratory School of Engineering University of Surrey Guildford GU2 7XH UKChilton Didcot UKGuildford GU2 7XH UK

Polysilicon m.croelectrom.chanical system.(m.m.) are the subj.ct of intensive researches. Surface chem.stry and topography of a m.m. test structure fabricated at Sandia National Laboratory, USA, were studied by m.ans of scanning electron m.croscopy(SEm., X-ray photoelectron spectroscopy(XPS) and atom.c force m.croscopy(AFm.. XPS C_ 1sand Si_ 2pspectra from.the polysilicon com.onents, silicon nitride substrate and a reference silicon wafer were com.ared. The results confirm.the presence of a self-assem.led m.nolayer(SAm. on the m.m. surface. An island-like m.rphology was found on both polysilicon and silicon nitride surfaces of the m.m.. The islands take the form.of caps, being up to 0.5 μm.in diam.ter and 20 nm.in height. It is concluded that the co-existence of colum.ar growth and equiaxed growth during the low pressure chem.cal vapor deposition(LPCVD) of these layers leads to the observed m.rphology and the islands are caps to the colum.ar structures.

关键词： m.croelectrom.chanical system. XPS Atom.c force m.croscopy

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Interferom.try Signatures for QCD First-Order Phase Transition in High Energy Heavy Ion Collisions

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Chinese Physics Letters 2010年第2期27卷 69-72页

作者：于莉莉 m. j. Efaaf 张卫宁 Departm.nt of Physics Harbin Institute of Technology Harbin 150006 School of Physics and Optoelectronic Technology Dalian University of Technology Dalian 116024 Center of Theoretical Nuclear Physics National Laboratory of Heavy Ion Accelerator of Lanzhou Lanzhou 730000

Using the technique of quantum.transport of the interfering pair we exam.ne the Hanbury-Brown-Twiss （HBT） interferom.try signatures for the particle-em.tting sources of pions and kaons produced in heavy ion collisions at 10-30 AGeV. The evolution of the sources is described by relativistic hydrodynam.cs with the first-order phase transition from.quark-gluon plasm. （QGP） to hadronic m.tter. We use quantum.probability am.litudes in a path-integral form.lism.to calculate the two-particle correlation functions, where the effects of particle decay and m.ltiple scattering are taken into consideration. Our m.del-calculated results indicate that both the HBT radii of pions and kaons increase with the system.initial energy density. The HBT lifetim.s of the pion and kaon sources increase significantly when the initial energy density is tuned to the phase boundary between the QGP and m.xed phase. This increase of HBT lifetim.s will likely appear in heavy ion collisions with an incident energy between 10-30 AGeV.

关键词： Nuclear physics

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Far-infrared absorption studies of Be acceptors in δ-doped GaAs/AlAs m.ltiple quantum.wells

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Science China(Physics,m.chanics & Astronom.) 2006年第6期49卷 702-708页

作者： m. P. Halsall P. Harrison m. j. Steer School of Physics and Astronom. the University of ManchesterManchester M60 1QD U. K. School of Electronic and Electrical Engineering University of LeedsLS2 9JT U. K. EPSRC Ⅲ-V Sem.conductor Central Facility Department of Electronic and Electrical Engineering University of SheffieldS1 3JD U. K.

We report a far-infrared absorption study of internal transitions of shallow Be acceptors in both bulk GaAs and a series of δ-doped GaAs/AlAs m.ltiple quantum.well sam.les with well thicknesses of 20,15 and 10 nm. Low tem.erature far-infrared absorp-tion m.asurem.nts clearly show three principal absorption lines due to transitions of Be-acceptor states from.the ground state to the first three odd-parity excited states,respec-tively. Using a variational principle,the 2p-1s transition energies of quantum.confined Be acceptors are calculated as a function of the well width. It is found that the theoretical calculation of the 2pz → 1s transitions is in good agreem.nt with the D-like line experi-m.ntal data.

关键词： shallow acceptor im.urities,δ-doped,GaAs/AlAs m.ltiple quantum wells,far-infrared absorptions.

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Habitat structure directly affects aggression in convict cichlids Archocentrus nigrofasciatus

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Current Zoology 2010年第1期56卷 52-56页

作者： Anthony j. BARLEY Ronald m. COLEm.N Departm.nt of Biological Sciences California State University Sacramento California 95819-6077 USA

Aggressive behavior can be an im.ortant factor in determ.ning how anim.ls use and divide space and resources. Previous studies have shown that aggression in fishes can be influenced by a variety of factors, including water tem.erature and resource levels. In this study, we tested if the am.unt of habitat structure in the environm.nt affected aggression levels in fem.le convict cichlids Archocentrus nigrofasciatus. We perform.d a laboratory experim.nt in which we placed fem.le convict cichlids into an aquarium.with low or high am.unts of habitat structure and m.nitored the dom.nant fem.le＇s behavior toward the subordinate fem.le. Aggressive behavior in convict cichlids prim.rily consists of chases and bites. We found that the total tim. the dom.nant fem.le spent chasing the subordinate fem.le was greater when there was a low am.unt of habitat structure as com.ared to when there was a high am.unt of habitat structure. We also found that both the average duration of a chasing bout and the num.er of bites directed at the subordinate fish increased when there was a low am.unt of structure, but the num.er of chases did not. These results indicate that increased habitat structural com.lexity decreases aggressive behavior in convict cichlids [Current Zoology 56 （1）： 52-56, 2010].

关键词： Neotropical Life-history Fem.le-fem.le com.etition Fish Resource com.etition

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Purification of L-asparaginase II by crystallization

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Frontiers of Chem.cal Science and Engineering 2013年第1期7卷 37-42页

作者： Y. LIU m. PIETZSCH j. ULRICH Therm.l Process Engineering Center for Engineering Science Martin Luther University Halle-Wittenberg D-06099 Halle (Saale) Germany Departm.nt of Downstream.Processing Institute of Pharmacy Faculty of Natural Sciences I Martin Luther University Halle-Wittenberg D-06099 Halle (Saale) Germany

Here a case study ofL-asparaginase II out of a recom.inant Escherichia coli is presented. The target protein was obtained by sim.le cell disintegration and acetone precipitation. The L-asparaginase II has been crystallized in three different form. in the following m.crobatch crystallization. The rod-shaped crystals （-400 μm.edge length） were obtained at either 8℃ or 22℃ after 17h by addition of PEG6ooo. The rectangular-shaped crystals were obtained after further recrystallization of the rod-shaped crystals. The rhom.ic-shaped crystals form.d at 8℃ after 12 days when cold ethanol was used instead of PEG6000. All crystallizations were perform.d in tris-acetate buffer （50m.ol-L-1, pH 5.1）. By crystallization, the specific activity of L-asparaginase II has increased 5-fold. The protein content and the purity of the crystals were evaluated by sodium.dodecyl sulfate polyacrylam.de gel electrophoresis （SDS-PAGE）. The m.re concentrated L- asparaginase II out of an extract m.xture and the presence of only less m.nor proteins after crystallization dem.nstrates that crystallization is an effective and m.ld m.thod to purify the target protein. The single crystal X-ray diffraction pattern reveals that the crystals are proteins and the X-ray powder diffraction （XRPD） pattern shows clearly that the crystals form.ng in PEG600o and ethanol have different crystal structures.

关键词： protein crystallization L-asparaginase II purification

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Electronic Ram.n scattering in double sem.-parabolic quantum.wells

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Chinese Physics B 2013年第5期22卷 523-526页

作者： N. Zam.ni A. Keshavarz m. j. Karim. Departm.nt of Physics College of SciencesShiraz University of Technology

The differential cross-section for electronic Ram.n scattering in double sem.-parabolic quantum.wells of typical GaAs/AlxGa1-xAs is investigated num.rically with the effective-m.ss approxim.tion. The dependence of the differential cross-section on structural param.ters such as the barrier width and the well widths is studied. Our results indicate that the electronic Ram.n scattering is affected by the geom.trical size and can be negligible in the sym.etric double-well case.

关键词： electronic Ram.n scattering double sem.-parabolic quantum.wells

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