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Characterization of carotenoid biosynthetic pathway genes in the pea aphid(Acyrthosiphon pisum)revealed by heterologous complementation and RNA interference assays

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Insect Science 2022年第3期29卷 645-656页

作者： Bi-Yue ding Xiu-Cheng Xie Feng Shang guy Smagghe Jin-Zhi Niu Jin-Jun Wang Key Laboratory of Entomology and Pest Control Engineering College of Plant ProtectionSouthwest UniversityChongqingChina International Joint Laboratory of China-Belgium on Sustainable Crop Pest ControlAcademy of Agricultural SciencesSouthwest UniversityChongqingChina department of Plants and Crops Faculty of Bioscience EngineeringGhent UniversityGhentBelgium

Carotenoids are involved in many essential physiological functions and are produced from geranylgeranyl pyrophosphate through synthase,desaturase,and cyclase *** the pea aphid(Acyrthosiphon pisum),the duplication of carotenoid biosynthetic genes,including carotenoid synthases/cyclases(ApCscA-C)and desaturases(ApCdeA-d),through horizontal gene transfer from fungi has been detected,and ApCdeB has known dehydrogenation ***,whether other genes contribute to aphid carotenoid biosynthesis,and its specific regulatory pathway,remains *** the current study,functional analyses of seven genes were performed using heterologous complementation and RNA interference *** bifunctional enzymes ApCscA-C were responsible for the synthase of phytoene,and ApCscC may also have a cyclase ***,ApCdeC,and ApCded had diverse dehydrogenation *** catalyzed the enzymatic conversion of phytoene to neurosporene(three-step product),ApCdeC catalyzed the enzymatic conversion of phytoene to ζ-carotene(two-step product),and ApCded catalyzed the enzymatic conversion of phytoene to lycopene(four-step product).Silencing of ApCscs reduced the expression levels of ApCdes,and silencing these carotenoid biosynthetic genes reduced the α-,β-,and γ-carotene levels,as well as the total carotenoid *** results suggest that these genes were activated and led to carotenoid biosynthesis in the pea aphid.

关键词： carotenoid biosynthesis heterologous complementary pea aphid RNA interference

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Nanocrystalline and Nanocomposite Magnetic Materials and Their Applications

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Journal of Iron and Steel Research(International) 2007年第4期14卷 69-74页

作者： robert d Shull Magnetic Materials Group National Institute of Standards and TechnologyGaithersburg MD 20899MarylandUSA

Nanocrystalline materials can possess bulk properties quite different from those commonly associated with conventional large-grained materials. Nanocomposites, a subset of nanocrystalline materials, in addition have been found to possess magnetic properties which are similar to, but different from, the properties of the individual constituents. New magnetic phenomena, unusual property combinations, and both enhanced and diminished magnetic property values are just some of the changes observed in magnetic nanocomposites from conventional magnetic materials. Here, a description will be presented of some of the exciting new properties discovered in nanomaterials and the magnetic applications envisioned for them.

关键词： nanocomposite ferromagnet magnetoresistance magnetic refrigeration domain imaging

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寓言历久弥新

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青年视觉 2024年第1期 132-145页

作者： Jeffrey Art d'Egypte(图) 不详

在过去的六十多年间,大地艺术已完成几次悄然的转向:整体上,robert Smithson《螺旋码头》式的在地创作仍在继续,信手来以呼应自然,也有越来越多的创作者借助更多元的材料、形式,思考全球化和地域文明、历史和当下——从2021年开始,每年... 详细信息

在过去的六十多年间,大地艺术已完成几次悄然的转向:整体上,robert Smithson《螺旋码头》式的在地创作仍在继续,信手来以呼应自然,也有越来越多的创作者借助更多元的材料、形式,思考全球化和地域文明、历史和当下——从2021年开始,每年一度在埃及吉萨金字塔群举办的Forever Is Now展览,再次扩大和丰富了这个艺术门类的内涵,它将文化遗产、自然、当代装置、创作者和欣赏者共同纳入一个互动情境中,讲述一个历久弥新的寓言:其发散的意义生成取决于地缘和创作者,也取决于欣赏的视角。

关键词：互动情境大地艺术意义生成文化遗产地域文明金字塔历久弥新全球化

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Coping with COVId-19 in Sub-Saharan Africa:What Might the Future Hold?

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Virologica Sinica 2020年第6期35卷 875-884页

作者： Franck J.d.Mennechet guy R.Takoudjou dzomo Institute of Molecular Genetic of Montpellier CNRSUniversity of MontpellierMontpellier 34090France University Hospital Complex the"Bon Samaritain" N’DjamenaBP 456Republic of Chad

The African COVId-19 Scenario On december 31st,2019 an unexplained case of pneumonia was reported in Wuhan,Hubei Province,China(Zhou et al.2020).On January 9th,2020,Chinese authorities and the World Health Organization(WHO)officially announced the discovery of a new type of coronavirus called SARS-Co V-2 that causes the coronavirus disease 2019(COVId-19)。

关键词： COV Africa authorities

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Influence of MBBR carrier geometrical properties and biofilm thickness restraint on biofilm properties,effluent particle size distribution,settling velocity distribution,and settling behaviour

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Journal of Environmental Sciences 2022年第12期34卷 138-149页

作者： Raheleh Arabgol Peter A.Vanrolleghem robert delatolla department of Civil Engineering University of Ottawa161 Louis PasteurK1N 6N5 ONCanada ModelEAU Département de génie civil et de génie des eauxUniversitéLaval1065 av.de la MédecineQuébecCanada

The relatively poor settling characteristics of particles produced in moving bed biofilm reactor(MBBR)outline the importance of developing a fundamental understanding of the characterization and settleability of MBBR-produced *** influence of carrier geometric properties and different levels of biofilm thickness on biofilm characteristics,solids production,particle size distribution(PSd),and particle settling velocity distribution(PSVd)is evaluated in this *** analytical Vi CAs method is applied to the MBBR effluent to assess the distribution of particle settling *** method is combined with microscopy imaging to relate particle size distribution to settling *** conventionally loaded MBBR systems are studied at a similar loading rate of 6.0 g/(m^(2)·day)and with different carrier *** AnoxK^(TM)K5 carrier,a commonly used carrier,is compared to so-called thickness-restraint carriers,AnoxK^(TM)Z-carriers that are newly designed carriers to limit the biofilm ***,two levels of biofilm thickness,200μm and 400μm,are studied using AnoxK^(TM)Z-200 and Z-400 *** analysis confirms that K5 carriers demonstrated a significantly different biofilm mass,thickness,and density,in addition to distinct trends in PSd and PSVd in comparison with ***,in comparison of thickness-restraint carriers,Z-200 carrier results did not vary significantly compared to the Z-400 *** K5 carriers showed the lowest production of suspended solids(0.7±0.3 gTSS/day),thickest biofilm(281.1±8.7μm)and lowest biofilm density(65.0±1.5 kg/m^(3)).The K5 effluent solids also showed enhanced settling behaviour,consisting of larger particles with faster settling velocities.

关键词： MBBR Particle size distribution(PSd) Particle settling velocity distribution(PSVd) Settling behaviour ViCAs z-carriers

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Epidemic time series similarity is related to geographic distance and age structure

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Infectious disease Modelling 2022年第4期7卷 690-697页

作者： Tad A.dallas Grant Foster robert L.Richards Bret d.Elderd department of Biological Sciences University of South CarolinaColumbiaSC29208USA department of Biological Sciences Louisiana State UniversityBaton RougeLA70802USA

Objective:More similar locations may have similar infectious disease *** is clear overlap in putative causes for epidemic similarity,such as geographic distance,age structure,and population *** compare the effects of these potential drivers on epidemic similarity compared to a baseline assumption that differences in the basic reproductive number(R0)will translate to differences in epidemic ***:Using COVId-19 case counts from United States counties,we explore the importance of geographic distance,population size differences,and age structure dissimilarity on resulting epidemic ***:We find clear effects of geographic space,age structure,population size,and R0 on epidemic similarity,but notably the effect of age structure was stronger than the baseline assumption that differences in R0 would be most related to epidemic ***:Together,this highlights the role of spatial and demographic processes on SARS-CoV2 epidemics in the United States.

关键词： Epidemic similarity SARS-CoV2 Age structure distance decay

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Modified Circumpolar deep Water inflow to the dotson-Getz Trough in the summers of 2020 and 2022

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Advances in Polar Science 2023年第2期34卷 80-90页

作者： XIE Chunhu SHI Jiuxin SUN Yongming JIANG Jindong guy dWILLIAMS SHUAI Hongtao LIN Lijin XIAO Changhao CAO Yong WANG Kun Physical Oceanography Laboratory Ocean University of ChinaQingdao 266100China Center for Ocean and Climate Research First Institute of OceanographyMinistry of Natural ResourcesQingdao 266061China College of Marine Sciences Shanghai Ocean UniversityShanghai 201306China

The melting of the West Antarctic Ice Shelf has increased since the 1990s,driven by the relatively warm Circumpolar deep Water(CdW)that penetrates into the West Antarctic Ice Shelf cavities through submarine glacial troughs across the continental *** this study,temperature,salinity,and current velocity data obtained by the Chinese National Antarctic Research Expedition in the dotson-Getz Trough(dGT)shows clear differences in distribution of modified Circumpolar deep Water(mCdW)in the summers of 2020 and *** with contemporaneous wind data and additional temperature and salinity data from instrumented seals,the processes and mechanisms responsible for this variation are *** with 2020,there is a significant increase in mCdW thickness in 2022,with a doubling of total heat content as the mCdW inflow path across the dGT shifts towards the eastern *** propose that a southward shift in the westerly winds in the summer of 2022 moved the upper oceanic divergence zone southward towards the continental slope,promoting the upwelling of mCdW above 500 ***,stronger westerly winds over the continental slope strengthened the eastward undercurrent,increasing the transport of this mCdW and its associated heat content to the dGT through Ekman *** observations show there is strong interannual variability in the strength,path and extent of mCdW inflows to the dGT and that care must be taken when planning observation programs for long-term monitoring of the oceanic heat input to the ice shelves of this globally significant region.

关键词： modified Circumpolar deep Water wind dotson-Getz Trough Amundsen Sea Antarctica

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Evolution of stress fields during the supercontinent cycle

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Geodesy and Geodynamics 2022年第4期13卷 363-375页

作者： Alexander Bobrov Alexey Baranov robert Tenzer Schmidt Institute of Physics of the Earth Russian Academy of SciencesMoscowRussia Institute of Earthquake Prediction Theory and Mathematical Geophysics Russian Academy of SciencesMoscowRussia department of Land Surveying and Geo-Informatics Hong Kong Polytechnic UniversityHong KongChina

We investigate the evolution of stress fields during the supercontinent cycle using the 2d Cartesian geometry model of thermochemical convection with the non-Newtonian rheology in the presence of floating deformable *** the course of the simulation,the supercontinent cycle is implemented several *** number of continents considered in our model as a function of time oscillates around *** lifetime of a supercontinent depends on its *** results suggest that immediately before a supercontinent breakup,the over-lithostatic horizontal stresses in it(referring to the mean value by the computational area)are tensile and can reach-250 *** the same time,a vast area beneath a supercontinent with an upward flow exhibits clearly the over-lithostatic compressive horizontal stresses of 50-100 МРа.The reason for the difference in stresses in the supercontinent and the underlying mantle is a sharp difference in their *** large parts of the mantle,the over-lithostatic horizontal stresses are in the range of±25 MPa,while the horizontal stresses along subduction zones and continental margins are significantly *** the process of continent-to-continent collisions,the compressive stresses can approximately reach 130 MPa,while within the subcontinental mantle,the tensile over-lithostatic stresses are about-50 *** dynamic topography reflects the main features of the su-percontinent cycle and correlates with real *** the breakup and immediately after the disin-tegration of the supercontinent,continents experience maximum *** the supercontinent cycle,topographic heights of continents typically vary within the interval of about±1.5 km,relatively to a mean *** maxima of orogenic formations to about 2-4 km are detected along continent-to-continent collisions as well as when adjacent subduction zones interact with continental margins.

关键词： Supercontinent cycle Floating deformable continents Thermochemical convection Horizontal stresses dynamic topography

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1995-2015年中国人口迁移的时空变化特征

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地理学报 2022年第2期77卷 411-425页

作者：柯文前朱宇陈晨 guy JAbel 林李月林洁福建师范大学地理研究所福州350007 湿润亚热带生态地理过程教育部重点实验室(福建师范大学) 福州350007 上海大学亚洲人口研究中心上海200444

本文利用人口普查数据,估算了1995—2015年中国地(市)间人口O-d迁移流和迁移率,结合GIS空间分析和社会网络分析方法,揭示了20年间中国人口迁移的时空变化特征。研究发现:(1)中国人口迁移由相对不活跃、局部地区参与的"低活性时代",逐步... 详细信息

本文利用人口普查数据,估算了1995—2015年中国地(市)间人口O-d迁移流和迁移率,结合GIS空间分析和社会网络分析方法,揭示了20年间中国人口迁移的时空变化特征。研究发现:(1)中国人口迁移由相对不活跃、局部地区参与的"低活性时代",逐步走向相对活跃、绝大多数地区参与的"高活性时代"。(2)人口迁移地域类型的时空演化过程呈现出各活跃型地(市)不断扩散,而非活跃型地(市)大幅缩减的特点。(3)人口迁移网络以"胡焕庸线"为界,东、西两侧迁移流"东密西疏"且差异悬殊,这一空间格局具有很强的稳定性和顽健性。(4)在人口省内迁移持续增强,以及跨省迁移中沿海三大城市群吸引力的"此消彼长"和西南地区吸引力不断增强的背景下,东中西部地区的人口迁移流场结构表现为:沿海地区主要城市群内部分化和影响范围减弱,中部地区(除湖北省)未能演化出以省为单元的独立社区,西部地区则是西北相对稳定而西南持续变动。

关键词：人口迁移地域类型社区时空变化中国

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Effectiveness of measures aiming to stabilize urban gullies in tropical cities:Results from field surveys across ***

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International Soil and Water Conservation Research 2023年第1期11卷 14-29页

作者： Eric Lutete Landu guy Ilombe Mawe Fils Makanzu Imwangana Charles Bielders Olivier dewitte Jean Poesen Aurélia Hubert Matthias Vanmaercke department of Geography(U.R.SPHERES) University of LiegeClos Mercator 34000LiègeBelgium department of Geoscience University of KinshasaKinshasa Mont-AmbaCongo department of Natural resources management University of KinshasaKinshasa Mont-AmbaD.R Congo department of Geology Oficial University of de BukavuCongo Geomorphology and Remote Sensing Laboratory Center for Geological and Mining ResearchCongo Earth and Life Institute-Environmental Sciences Universite catholique de LouvainCroix du sud 2L7.05.021348Louvain-la-NeuveBelgium Royal Museum for Central Africa Leuvensesteenweg 13B-3080TervurenBelgium department of Earth and Environmental Sciences KU LeuvenCelestijnenlan 200E3001HeverleeBelgium Institute of Earth and Environmental Sciences Maria-Curie Sklodowska University(UMCS)Krasnicka 2D20-718LublinPoland

Urban gullies are a rapidly growing concern in many tropical cities of the Global *** measures are already implemented for their ***,an overview of these measures and their overall effectivenesss is currently *** aim at addressing this gap by documenting existing ini-tiatives to stabilize urban gullies in *** and assessing their overall *** this end we conducted extensive field campaigns in Kinshasa,Kikwit and Bukavu and combined our terrain obser-vations with data on gully expansion rates(derived from series of satellite imagery).In total,we char-acterized present and past stabilization initiatives for 398 urban *** 69 of these gullies,the effect of a specific measure on gully expansion rates could be *** show that for the large ma-jority of gullies,various measures have been ***,these are mainly ad-hoc measures installed by the affected *** structural measures based on larger engineering works were observed for only 20-30%of *** huge efforts invested in the installation of measures strongly contrast with their overall low impact Among all strategies,only the deviation of runoff resulted in significantly lower expansion rates after *** numerous initiatives that rely on the sparse means available seem to have limited *** does not imply,however,that they are completely ineffective and should be *** on our findings,we formulate recommendations for further research on how to effectively prevent and stabilize urban gullies,taking into account the difficult environmental and socio-economic context.

关键词： Gully expansion rate Head and channel measures Catchment measures Global South Urban hazard

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