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The evolutionary consequences of selfish genetic elements

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Current Zoology 2016年第6期62卷 655-658页

作者： Anna k. LINDHOLM Tom A.R. price Department of Evolutionary Biology and Environmental Studies University of Zurich Winterthurerstrasse 190 Zurich Switzerland Institute of Integrative Biology University of Liverpool Crown Street Liverpool UK

The traditional view of the genome was once that it is broadly cooperative, with all genes working together amicably to improve the success of the individual as a whole. Benefits to the individual, after all, benefit all the component genes, as fair Mendelian inheritance ensures that all the genes and alleles a parent carries are equally likely to be inherited by an offspring. However, more detailed studies of inheritance have shown that this rosy view of cooperation within the genome is untrue. Instead, many genes act selfishly, manipulating gametogenesis to bias transmission in their favor （Butt and Trivers 2006）. This increases their representation in offspring at a cost to the fitness of the individual and the cooperative genes.

关键词：遗传因素进化基因组孟德尔遗传等位基因合作多基因后代

Secondary steady-state and time-periodic flows from a basic flow with square array of odd number of vortices

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Applied Mathematics and Mechanics(English Edition) 2023年第3期44卷 447-458页

作者： Zhimin CHEN W.G.price School of Mathematics and Statistics Shenzhen UniversityShenzhen 518060Guangdong ProvinceChina Ship Science University of SouthamptonSouthampton SO171BJU.K.

In a magnetohydrodynamic(MHD)driven fluid cell,a plane non-parallel flow in a square domain satisfying a free-slip boundary condition is *** energy dissipation of the flow is controlled by the viscosity and linear *** latter arises from the influence of the Hartmann bottom boundary layer in a three-dimensional(3D)MHD experiment in a square bottomed *** basic flow in this fluid system is a square eddy flow exhibiting a network of N~2 vortices rotating alternately in clockwise and anticlockwise *** N is odd,the instability of the flow gives rise to secondary steady-state flows and secondary time-periodic flows,exhibiting similar characteristics to those observed when N=*** this reason,this study focuses on the instability of the square eddy flow of nine *** is shown that there exist eight bi-critical values corresponding to the existence of eight neutral eigenfunction ***,there exist non-real neutral eigenfunctions,which produce secondary time-periodic flows exhibiting vortices merging in an oscillatory *** Hopf bifurcation phenomenon has not been observed in earlier investigations.

关键词： two-dimensional(2D)Navier-Stokes equation non-parallel square vortex flow primary bifurcation secondary steady-state flow secondary time-periodic flow

Three thousand years in Tibet

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National Science Review 2020年第1期7卷 129-130页

作者： Bettina Harr Trevor price Max-planck-Institut für Evolutionsbiologie Department of Ecology and Evolution University of Chicago

Humans have come to inhabit nearly every terrestrial environment. Their commensals have followed them and have consequently become some of the most abundant and widespread species on Earth, in the process becoming exposed to a variety of abiotic and biotic stressors. For example, the house sparrow was introduced from the Uk to North America in the

关键词： Three thousand years in Tibet

A NUMERICAL METHOD FOR SIMULATING NONLINEAR FLUID-RIGID STRUCTURE INTERACTION pROBLEMS

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Acta Mechanica Solida Sinica 2005年第2期18卷 95-109页

作者： price W.G. The School of Engineering Sciences Ship ScienceUniversity of SouthamptonSouthampton SO17 1BJEngland

A numerical method for simulating nonlinear fluid-rigid structure interaction problems is developed. The structure is assumed to undergo large rigid body motions and the fluid flow is governed by nonlinear, viscous or non-viscous, field equations with nonlinear boundary conditions applied to the free surface and fluid-solid interaction interfaces. An Arbitrary-LagrangianEulerian (ALE) mesh system is used to construct the numerical model. A multi-block numerical scheme of study is adopted allowing for the relative motion between moving overset grids, which are independent of one another. This provides a convenient method to overcome the difficulties in matching fluid meshes with large solid motions. Nonlinear numerical equations describing nonlinear fluid-solid interaction dynamics are derived through a numerical discretization scheme of study. A coupling iteration process is used to solve these numerical equations. Numerical examples are presented to demonstrate applications of the model developed.

关键词： fluid-structure interaction nonlinear numerical analysis ALE description overset grids flow around bluff-body

Implications of membrane fouling toward the removal of the pharmaceutical sulfamethoxazole by nanofiltration processes

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Journal of Zhejiang University-Science A(Applied physics & Engineering) 2011年第8期12卷 575-582页

作者： Alexander SIMON William price Long Duc NGHIEM School of Civil Mining and Environmental Engineering the University of Wollongong School of Chemistry the University of Wollongong

The influence of membrane fouling on the retention of the trace organic contaminant sulfamethoxazole by a nanofiltration(NF) process was *** fouling caused a severe flux decline possibly due to pore blocking and adsorption directly after the commencement of the fouling layer *** membrane-foulant interactions were absent for colloidal fouling,which resulted in a more gradual flux *** charge played a significant role in the separation process of inorganic salts,where the retention was the highest in a caustic environment(high pH) due to more swollen membrane material caused by the higher negative charge on the *** fouling and a combination of colloidal and organic fouling led to a significant increase in the membrane negative *** influence of membrane fouling on solute retention was dependent on the fouling behaviour and the physicochemical properties of the model foulants,where the model foulants probably contributed to an increase in the retention of charged solutes due to enhanced electrostatic *** fouling caused an increase in the retention of inorganic salts and sulfamethoxazole due to pore *** contrast,colloidal fouling caused a decrease in the retention of inorganic salts due to cake-enhanced concentration ***,the presence of a colloidal fouling layer did not reduce the retention of sulfamethoxazole.A mixture of colloidal and organic matter improved the retention of inorganic salts.A similar conclusion can be inferred for sulfamethoxazole at pH 4 when the compound exists in a neutral form.

关键词： Nanofiltration(NF) Organic fouling Colloidal fouling Combined fouling Trace organics Water reuse

Methane dehydroaromatization–A study on hydrogen use for catalyst reduction, role of molybdenum, the nature of catalyst support and significance of Bronsted acid sites

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Journal of Energy Chemistry 2019年第7期28卷 20-32页

作者： Vaidheeshwar Ramasubramanian Hema Ramsurn Geoffrey L.price Russell School of Chemical Engineering The University of Tulsa

Methane dehydroaromatization was studied over Mo/SiO2 and Mo/HZSM-5 with different Mo loadings(2, 5, 10 wt%) at 973 k and 1023 k in a recirculating batch reactor. H2 pretreatment at 1023 k prior to methane activation has significantly improved the catalyst activity with increase in Mo loading and reduced the induction time on benzene formation in both Mo/SiO2 and Mo/HZSM-5. 10 wt% Mo/HZSM-5 gave a maximum methane conversion of 19% and ~67% benzene selectivity at 1023 k. The XRD analysis of used catalysts revealed that the Mo O3 species were converted to β-Mo2C phase. Studies on Mo/SiO2 catalysts showed that benzene was formed even in the absence of acidic zeolite sites. Reactions of ethylene in the presence of pure silica, HZSM-5 and in a blank reactor revealed that conversion of ethylene to aromatics was similar in case of the blank reactor and silica. Thus, it is believed that molybdenum carbide sites act as active sites only for C–H bond activation of methane and ethylene formation. Even though, ethylene can undergo subsequent oligomerization without any catalytic aid to form benzene at973 k and above addition of acidic zeolites improved the selectivity of benzene.

关键词： Methane dehydroaromatization HZSM-5 Silica Molybdenum loading H2 pretreatment Acidic function

performance of Bt-susceptible and -heterozygous dual-gene resistant genotypes of Spodoptera frugiperda (***) (Lepidoptera:Noctuidae) in seed blends of non-Bt and pyramided Bt maize

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Insect Science 2021年第4期28卷 1147-1158页

作者： Marcelo Dimase Sebe Brown Graham p.Head paula A.price Wade Walker Wenbo Yu Fangneng Huang Department of Entomology Louisiana State University Agricultural CenterBaton RougeLouisianaUSA Dean Lee Research Station Louisiana State University Agricultural CenterAlexandriaLouisianaUSA Bayer Crop Science ChesterfieldMissouriUSA Macon Ridge Research Station Louisiana State University Agricultural CenterWinnsboroLouisianaUSA

A seed blend refuge has been implemented in the *** Belt for Bt maize resistance *** fall armyworm,Spodoptera frugiperda(***),is a target pest of Bt maize in the *** larvae of this pest are mobile,which may affect the efficacy of seed blend *** this study,field and greenhouse trials were conducted to determine the performance of Bt-susceptible(aabb)and-heterozygous dual-gene-resistant(AaBb)genotypes of *** in seed blends of non-Bt and pyramided Bt *** field trials evaluated larval survival,larval growth,and plant injury with aabb in seed blends of Bt maize expressing Cry1A.105/Cry2Ab2/Vip3A with 0–30%non-Bt *** tests investigated the performance of aabb and AaBb in seed blends of Cry1A.105/Cry2Ab2 with 0–30% non-Bt *** pure non-Bt maize plots,after 9–13 d of neonates being released on the plants,0.39 and 0.65 larvae/plant survived with leaf injury ratings of 4.7 and 5.9(Davis's 1–9 scale)in the field and greenhouse,*** contrast,live larvae and plant injury were virtually not observed on Bt plants across all planting *** occurrence and plant injury by aabb on non-Bt plants were similar between seed blends and pure non-Bt plantings,suggesting that the blended refuges could provide an equivalent susceptible population as structured refuge under the test *** the greenhouse,the two insect genotypes in seed blends performed similarly,indicating that the seed blends did not provide more favorable conditions for AaBb over *** information generated from this study should be useful in managing *** and evaluating if send blends could be suitable refuge options for Bt resistance management in the regions where the insect is a primary target pest.

关键词： Bt maize dual-gene resistance fall armyworm resistance management seed blend

A DIRECT SEARCH FRAME-BASED CONJUGATE GRADIENTS METHOD

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Journal of Computational Mathematics 2004年第4期22卷 489-500页

作者： I.D.Coope C.J.price DepartmentofMathematicsandStatistics UniversityofCanterburyPrivateBag4800ChristchurchNewZealand

A derivative-free frame-based conjugate gradients algorithm is presented. Convergence is shown for C^1 functions, and this is verified in numerical trials. The algorithm is tested on a variety of low dimensional problems, some of which are ill-conditioned, and is also tested on problems of high dimension. Numerical results show that the algorithm is effective on both classes of problems. The results are compared with those from a discrete quasiNewton method, showing that the conjugate gradients algorithm is competitive. The algorithm exhibits the conjugate gradients speed-up on problems for which the Hessian at the solution has repeated or clustered eigenvalues. The algorithm is easily parallelizable.

关键词： Conjugate gradients Derivative-free Frame-based methods Numerical results

Engineering heterogenous catalysts for chemical CO_(2) utilization:Lessons from thermal catalysis and advantages of yolk@shell structured nanoreactors

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Journal of Energy Chemistry 2021年第6期30卷 304-324,I0008页

作者： Cameron Alexander Hurd price Tomas Ramirez Reina Jian Liu DICp-Surrey Joint Centre for Future Materials Department of Chemical and Process EngineeringUniversity of SurreyGuildfordSurrey GU27XHUK State key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023LiaoningChina

The development of catalytic materials for the recycling CO_(2) through a myriad of available processes is an attractive field,especially given the current climate *** there is increasing publication in this field,the reported catalysts rarely deviate from the traditionally supported metal nanoparticle morphology,with the most simplistic method of enhancement being the addition of more metals to an already complex *** catalysts,especially yolk@shell catalysts with hollow voids,offer answers to the most prominent issues faced by this field,coking and sintering,and further potential for more advanced phenomena,for example,the confinement effect,to promote selectivity or offer greater protection against coking and *** work serves to demonstrate the current position of catalyst development in the fields of thermal CO_(2) reforming and hydrogenation,summarizing the most recent work available and most common metals used for these reactions,and how yolk@shell catalysts can offer superior performance and survivability in thermal CO_(2) reforming and hydrogenation to the more traditional ***,this work will briefly demonstrate the bespoke nature and highly variable yolk@shell ***,this review aims to illuminate the spatial confinement effect and how it enhances yolk@shell structured nanoreactors is presented.

关键词： Yolk@shell CO_(2)utilization Reforming Hydrogenation Confinement effect