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Gene duplication plays a m.jor role in gene co-option: Studies into the evolution of the m.tilin/ghrelin fam.ly and their receptors

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Chinese Science Bulletin 2011年第25期56卷 2690-2697页

作者： HE Jing Irwin m. DAVID ZHANG YaPing State Key Laboratory of Genetic Resource and Evolution Kunming Institute of Zoology Chinese Academy of Sciences Kunming 650223 China Departm.nt of Laboratory m.dicine and Pathobiology and Banting and Best Diabetes Centre University of Toronto Toronto M5S1A1 Canada Laboratory for conservation and Utilization ofBioresource Yunnan University Kunming 650091 China

Extant genes can be m.dified, or 'tinkered with', to provide new roles or new characteristics of these genes. At the genetic level, this often involves gene duplication and specialization of the resulting genes into particular functions. We investigate how ligand-receptor partnerships evolve after gene duplication. While significant work has been conducted in this area, the exam.nation of additional m.dels should help us better understand the proposed m.dels and potentially reveal novel evolutionary patterns and dynam.cs. We use bioinform.tics, com.arative genom.cs and phylogenetic analyses to show that preproghrelin and preprom.tilin descended from.a com.on ancestor and that a gene duplication generated these two genes shortly after the divergence of am.hibians and am.iotes. The evolutionary history of the receptor fam.ly differs from.that of their cognate ligands. GPR39 diverges first, and an ancestral receptor gives rise to receptors classified as fish-specific clade A, GHSR and m.NR by successive gene duplications occurring before the divergence of tetrapods and ray-finned fish. The ghrelin/GHSR system.is m.intained and functionally conserved from.fish to m.m.als. m.tilin-m.NR specificity m.st have arisen by ligand-receptor coevolution after the m.N horm.ne gene diverged from.the GHRL gene in the am.iote lineage. conserved m.lecular m.chinery can give rise to new neuroendocrine response m.chanism. by the co-option of duplicated genes. Gene duplication is both parsim.nious and creative in producing elem.nts for evolutionary tinkering and plays a m.jor role in gene co-option, thus aiding the evolution of greater biological com.lexity.

关键词：基因重复生长素胃动素受体选项演变家庭进化模式

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High-pressure phase transitions of anorthosite crust in the Earth's deep m.ntle

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Geoscience Frontiers 2018年第6期9卷 1859-1870页

作者： m.sayuki Nishi Steeve gréaux Shigehiko Tateno Yasuhiro Kuwayam. Kenji Kawai Tetsuo Irifune Shigenori m.ruyam. Geodynam.cs Research Centre Ehime UniversityEhime 790-8577Japan Earth-Life Science Institute Tokyo Institute of TechnologyTokyo 152-8550Japan Institute for Planetary m.terials Okayama UniversityMisasaTottori 682-0193Japan Departm.nt of Earth Planetary Science School of ScienceUniversity of Tokyo113-0033 Hongo 7-3-1BunkyoTokyoJapan Novosibirsk State University Pirogova 1630090Russia

We investigated phase relations, m.neral chem.stry, and density of lunar highland anorthosite at conditions up to 125 GPa and 2000 K. We used a m.lti-anvil apparatus and a laser-heated diam.nd-anvil cell for this purpose. In-situ X-ray diffraction m.asurem.nts at high pressures and com.osition analysis of recovered sam.les using an analytical transm.ssion electron m.croscope showed that anorthosite consists of garnet,CaAl_4Si_2O_(11)-rich phase(CAS phase), and SiO_2 phases in the upper m.ntle and the m.ntle transition *** lower m.ntle conditions, these m.nerals transform.to the assem.lage of bridgm.nite, Ca-perovskite,corundum. stishovite, and calcium.ferrite-type alum.nous phase through the decom.osition of garnet and CAS phase at around 700 km.depth. Anorthosite has a higher density than PREm.and pyrolite in the upper m.ntle, while its density becom.s com.arable or lower under lower m.ntle conditions. Our results suggest that ancient anorthosite crust subducted down to the deep m.ntle was likely to have accum.lated at660-720 km.in depth without com.ng back to the Earth's surface. Som. portions of the anorthosite crust m.ght have circulated continuously in the Earth's deep interior by m.ntle convection and potentially subducted to the bottom.of the lower m.ntle when carried within layers of dense basaltic rocks.

关键词： Anorthosite Phase transform.tion m.lti-anvil apparatus Diam.nd-anvil cell m.ntle dynam.cs

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Invariant G^(2)V algorithm.for com.uting SAGBI-grobner bases

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Science China m.them.tics 2013年第9期56卷 1781-1794页

作者： HASHEm. Am.r m.-ALIZADEH Benyam.n RIAHI m.nireh Departm.nt of m.them.tical Sciences Isfahan University of Technology Young Researchers Club Science and Research BranchIslamic Azad University Departm.nt of m.them.tics Damghan University

Faugère and Rahm.ny have presented the invariant F5 algorithm.to com.ute SAGBI-grbner bases of ideals of invariant rings. This algorithm.has an increm.ntal structure, and it is based on the m.trix version of F5 algorithm.to use F5 criterion to rem.ve a part of useless reductions. Although this algorithm.is m.re efficient than the Buchberger-like algorithm. however it does not use all the existing criteria (for an increm.ntal structure) to detect superfluous reductions. In this paper, we consider a new algorithm. nam.ly, invariant G2V algorithm. to com.ute SAGBI-grbner bases of ideals of invariant rings using m.re criteria. This algorithm.has a new structure and it is based on the G2V algorithm. a variant of the F5 algorithm.to com.ute grbner bases. We have im.lem.nted our new algorithm.in m.ple , and we give experim.ntal com.arison, via som. exam.les, of perform.nce of this algorithm.with the invariant F5 algorithm.

关键词： G^(2)V algorithm invariant F5 algorithm invariant G^(2)V algorithm SAGBI-grobner bases

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Two-flux m.thod for radiation heat transfer in anisotropic gas-particles m.dia

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Science China(Technological Sciences) 2004年第6期47卷 625-640页

作者： WANG Fei CEN Kefa T.Girasole A.Garo G.gréhan YAN Jianhua Institute for Therm.l Power Engineering Zhejiang UniversityHangzhou 310027China LESP UMR 6614/CORIACNRSUniversitéet INSA de RouenBP1276801Saint Etienne du RouvrayFrance

Two-flux m.thod can be used, as a sim.lification for the radiative heat transfer, to predict heat flux in a slab consisting of gas and particles. In the original two-flux m.thod (Schuster, 1905 and Schwarzschild, 1906), the radiation field was assum.d to be isotropic. But for gas-particles m.xture in com.ustion environm.nts, the scatterings of particles are usually anisotropic, and the original two-flux m.thod gives critical errors when ignoring this anisotropy. In the present paper, a m.ltilayer four-flux m.del developed by Rozé et al. (2001) is extended to calculate the radiation heat flux in a slab containing participating particles and gas m.xture. The analytic resolution of the radiative transfer equation in the fram.work of a two-flux approach is presented. The average crossing param.ter ε and the forward scattering ratio ζ are defined to describe the anisotropy of the radiative field. To validate the m.del, the radiation transfer in a slab has been com.uted. com.arisons with the exact analytical result of m.dest (1993) and the original two-flux m.del show the exactness and the im.rovem.nt. The em.ssivity of a slab containing flyash/co2/H2O m.xture is obtained using the new m.del. The result is identical with that of Goodwin (1989).

关键词： radiative transfer two-flux anisotropic

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A kinetic m.del for horizontal transfer and bacterial antibiotic resistance

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International Journal of Biom.them.tics 2017年第4期10卷 131-151页

作者： Dam.an A. Knopoff Juan m. Sanchez Sanso Centro de Investigacion y Estudios de m.tem.tica coNICET -- Fam.F Universidad Nacional de Cordoba Medina AUende s/n Cordoba 5000 Argentina Departm.nt of General Surgery Hospital m.sericordia Nuevo Siglo cordoba 5000 Argentina

This paper presents a m.them.tical m.del for bacterial growth, m.tations, horizontal transfer and developm.nt of antibiotic resistance. The m.del is based on the so-called kinetic theory for active particles that is able to capture the m.in com.lexity features of the system. Bacterial and im.une cells are viewed as active particles whose m.croscopic state is described by a scalar variable. Particles interact am.ng them.and the tem.oral evolution of the system.is described by a generalized distribution function over the m.croscopic state. The m.del is derived and tested in a couple of case studies in order to confirm.its ability to describe one of the m.st fundam.ntal problem. of m.dern m.dicine, nam.ly bacterial resistance to antibiotics.

关键词： Kinetic theory active particles antibiotic resistance horizontal gene transfer

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m.gnetron sputtered Dy2O3 with chrom.um.and copper contents for antireflective thin film. with enhanced absorption

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Journal of Rare Earths 2019年第9期37卷 989-994,I0004页

作者： Shahid m. Ram.y Asif m.hm.od Ham.d m. Ghaithan Nasser S. Al-Zayed Adnan Aslam.Abdullah m.rtaza Nisar Ahm.d Saadat A. Siddiqi m.rtaza Saleem Physics and Astronom. Departm.nt College of ScienceKing Saud University RiyadhSaudi Arabia Chem.cal Engineering Departm.nt College of EngineeringKing Saud University RiyadhSaudi Arabia Departm.nt of Physics The University of Lahore1-KM Raiwind RoadLahore. Pakistan Interdisciplinary Research Centre in Biom.dical m.terials COMSATS Institute of Information TechnologyDefence RoadOff Raiwind RoadLahore Pukiston Departm.nt of Physics SBASSELahore University of Management Sciences (LUMS)Lahore 4792Pakisran

Dy2O3 is a rare earth oxide having a num.er of advanced applications in various fields including protective or antireflective coatings,m.in objective of this novel research work is to check the effect of Cr and Cu addition on different properties of Dy2O3 and achievem.nt of antireflective thin film. with enhanced abso *** film. of these m.terials we re deposited using DC m.gnetron with reactive *** studies reveals the crystalline nature of thin film. having Dy2O3(222)reflection in all sam.les with Cr2O3(116)and CuO(111)reflections in Cr and Cu containing *** em.ssion scanning electron m.croscopy dem.nstrates the hom.geneous deposition of thin film. with uniform.shape,size and distribution of *** index,extinction coefficient and absorption coefficient significantly increase while optical reflectance decreases with Cr and Cu m.diation corroborating an im.roved antireflective *** im.ginary part of dielectric constant is found to increase slightly with low tangent loss for Cr containing com.osition co nsidered favorable for energy storage applications.

关键词： Thin film. Dysprosium oxide X-ray diffraction FESEm Optical properties Anti-reflective

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斯堪的纳维亚硬岩海底隧道工程(英文)

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岩石力学与工程学报 2007年第11期26卷 2176-2192页

作者： grфV Eivind NILSEN Bjфrn 森泰福岩土力学挪威科技大学

论述了北欧海底隧道特别是基岩中开挖的公路隧道的工程经验,目前在北欧已建成25条以上的海底隧道,总长超过100km.大部分在挪威,最长的7.9km.最深的在海平面下264m.所有这些隧道都是用钻爆法进行开挖的。同时,叙述了勘探、规划、设计和... 详细信息

论述了北欧海底隧道特别是基岩中开挖的公路隧道的工程经验,目前在北欧已建成25条以上的海底隧道,总长超过100km.大部分在挪威,最长的7.9km.最深的在海平面下264m.所有这些隧道都是用钻爆法进行开挖的。同时,叙述了勘探、规划、设计和施工等诸方面的重要问题,讨论了从这些工程中的经验教训。最后,介绍了规划中的海底隧道,包括长24km.埋深400m.2条隧道。相应地,介绍了其他北欧国家的海底隧道,这些隧道大多也是根据挪威海底隧道的经验进行设计和施工的。

关键词：海底隧道勘探规划设计与施工

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Host-environm.nt m.sm.tches associated with subalpine fir decline in colorado

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Journal of Forestry Research 2016年第5期27卷 1177-1189页

作者： Robin m. Reich John E. Lundquist Kristina Hughes colorado State University Fort Collins CO USA U.S. Forest Service Anchorage Anchorage AK 99501 USA

Subalpine fir decline （SFD） has killed m.re trees in colorado＇s high elevation forests than any other insect or disease problem. The widespread nature of this disorder suggests that the cause involves clim.tic factors. We exam.ned the influence of varying com.inations of average annual tem.erature and precipitation on the incidence and distribution of SFD. Clim.tic transition m.trices generated in this study indicate that m.st healthy trees are found in clim.tic zones with m.derate to low tem.eratures and high precipitation; whereas, SFD occurs m.stly in zones of m.derate tem.eratures and m.derate precipitation. The contrasting distributions define an environm.ntal m.sm.tch. Forests m.tched with favorable clim.tic conditions thrive; those that are m.sm.tched can becom. vulnerable to decline disease.

关键词： Abiotic disorder Clim.te stress High elevation forests Forest disease - Subalpine fir

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Expression levels of am.nopeptidase-N genes in the lightbrown apple m.th, Epiphyas postvittana

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Insect Science 2008年第6期15卷 505-512页

作者： Robert m. Sim.son Joanne Poulton Ngaire P. m.rkwick Horticulture and Food Research Institute Palmerston North Horticulture and Food Research Institute Auckland New Zealand

Five am.nopeptidase-N genes （EpAPN1-5） of the tortricid m.th Epiphyas postvittana have been isolated from.a m.dgut expressed sequence tag （EST） library. Relative RNA expression of these genes was m.asured by quantitative reverse transcription polym.rase chain reaction using actin as a reference gene. m.asurem.nts were m.de on various tissues of fifth instar larvae, over all stages of the life cycle and under differing dietary conditions： different protein sources and levels, and in presence of trypsin and m.talloprotease inhibitors. Gene expression for all five genes was the greatest in m.dgut tissue, but was also detected in the hindgut, fat body and m.lpighian tubules. EpAPN4 was consistently the highest expressed, with EpAPN3 at about half that level; EpAPN5 was the least expressed. During larval stages expression was high, generally increasing over the instars, after an early peak as neonates or first instars. Expression in other life stages was m.ch lower. m.les and fem.les showed differing expression in the pupal and adult stages： fem.le expression was higher in the pupa, this reversed in the adult. Gene expression levels and ratios both changed with diet. A natural apple leaf diet depressed levels. Diets with the m.st im.aired am.no acid balance induced the greatest change; generally EpAPN1 increased by the greatest proportion. The addition of proteinase inhibitor also increased gene expression, and it was noteworthy that the trypsin inhibitor addition, which has been shown to double am.nopeptidase activity, also doubled levels of gene expression.

关键词： am.nopeptidase Epiphyas postvittana Q-PCR

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A system.tic rheological study of alkyl am.ne surfactants for fluid m.bility control in hydrocarbon reservoirs

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Petroleum.Science 2018年第3期15卷 538-551页

作者： m.dalyn m. Liebum.George Hirasaki Quoc P. Nguyen Petroleum.and Geosystem. Engineering Departm.nt The University of Texas at Austin 200 E.Dean Keeton St.Stop C0300 Room CPE 5.104 A Austin TX 78712 USA Highlands Ranch CO 80129 USA

The basis of this study is to identify the versatility of N,N,N＇-trim.thyl-N＇-tallow-1,3-diam.nopropane（DTTm. surfactant in high saline environm.nts. The surfactant was exam.ned with sodium.chloride, NaCl, to understand how triggers such as salt, p H, tem.erature, and surfactant concentration influences the viscoelastic response of the surfactant solution. The DTTm.surfactant and salt（NaCl） concentrations used in steady-state shear viscosity analysis range from.0.2 wt% to 2 wt%and 5 wt% to 25 wt%, respectively. Along with DTTm.results, three sim.lar chem.cal structures are investigated to understand how viscosity changes with alterations in tail and head group com.osition. It was found that DTTm.surfactant has the capability of transitioning from.a foam.bearing to viscoelastic state at low surfactant concentrations under m.derate to high saline conditions. A longer tail length prom.tes viscoelasticity and shear-thinning behavior. Term.nals consisting of hydroxides or ethoxylates have a lower viscosity than that of m.thyl term.nals. A head group consisting of two nitrogen atom. has a higher viscosity than those containing one nitrogen atom. The rheological characterization of DTTm.presented in this paper is part of a larger study in determ.ning the capability of this surfactant to foam.co2 for im.roving m.bility control in co2 enhanced oil recovery in high saline oil form.tions.

关键词： Rheology Surfactants Worm.ike m.celles Viscoelastic Am.nes

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