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Convergent evolution of brain m.rphology and com.unication m.dalities in lizards

Current Zoology 2015年第2期61卷 281-291页

作者： christopher D. ROBIN.SON m.chael S. PATTON Britm.y m. ANDRE m.chele A. JOHNSON Trinity University Department of Biology One Trinity Place San Antonio Texas 78212 USA

Anim.ls com.unicate inform.tion within their environm.nts via visual, chem.cal, auditory, and/or tactile m.dalities. The use of each m.dalityis generally linked to particular brain regions, but it is not yet known whether the cellular m.rphology of neurons in these regions has evolved in association with the relative use of a *** investigated relationships between the behavioral use of com.unication m.dalities and neural m.rphologies in six lizard species. Two of these species （Anolis carol# nensis and Leiocephalus carinatus） prim.rily use visual signals to com.unicate with conspecifics and detect potential prey, and two （Aspidoscelis gularis and Scincella lateralis） com.unicate and forage prim.rily using chem.cal signals. Two other species （Hem.dactylus turcicus and Sceloporus olivaceus） use both visual and chem.cal signals. For each species, we perform.d beha- vioral observations and quantified rates of visual and chem.cal behaviors. We then cryosectioned brain tissues from.9-10 m.les of each species and m.asured the som. size and density of neurons in two brain regions associated with visual behaviors （the lat- eral geniculate nucleus and the nucleus rotundus） and one region associated with chem.cal behaviors （the nucleus sphericus）. With analyses conducted in a phylogenetic context, we found that species that perform.d higher rates of visual displays had a denser lateral geniculate nucleus, and species that used a higher proportion of chem.cal displays had larger som.s in the nucleus sphericus. These relationships suggest that neural m.rphologies in the brain have evolved convergently in species with sim.lar com.unication behaviors .

关键词： Brain Com.unication m.dality Lizards Pherom.nes Social behavior Vision

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Continuous synthesis of iron oxide （Fe3O4） nanoparticles via therm.l decom.osition

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Particuology 2016年第3期14卷 47-53页

作者： William.Glasgow Ben Fellows Bin Qi Taghi Darroudi christopher Kitchens Longfei Ye Thom.s m. Crawford O. Thom.son m.fford Departm.nt of m.terial Science and Engineering Center for Optical Materials Science and Engineering Technologies Clemson University 91 Technology Drive Anderson SC29625 USA Electron m.croscopy Laboratory Department of Materials Science and Engineering Clemson University Clemson SC29625 USA Departm.nt of Chem.cal and Biom.lecular Engineering Clemson University Clemson SC 29634 USA Departm.nt of Physics and Astronom. and Sm.rt State Center for Experim.ntal Nanoscale Physics University of South Carolina 712 Main Street Columbia SC29208 USA

Iron oxide nanoparticles have becom. of great interest in the m.dical field for their potential uses in areas such as biom.gnetic im.ging and hypotherm.a cancer treatm.nt. Traditionally, particles for these applications are produced through batch-based m.thodologies. Herein, we dem.nstrate an alternative continuous flow production m.thod for the synthesis of Fe304 iron oxide nanoparticles. Advantages of continuous flow over the batch m.thod include consistent form.tion of uniform.y spherical particles, thorough m.xing of reactants, and capacity for high-volum. particle production. In this study, a continu- ous flow reaction m.chanism.was proposed in which stoichiom.tric control of reactants had the potential to control final particle size. The project was conducted under the supposition that the iron oleatelligand ratio in the precursor was the greatest size control factor, with a higher ratio resulting in sm.ller parti- cles. The resulting particles produced by this continuous m.thod were characterized by high-resolution transm.ssion electron m.croscopy, X-ray diffraction, and m.gnetom.try.

关键词： Continuous flow Iron oxide m.gnetiteSynthesis

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Strategies towards statistically robust interpretations of in situ U-Pb zircon geochronology

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Geoscience Frontiers 2016年第4期7卷 581-589页

作者： christopher J.Spencer christopher L.Kirkland Richard J.m.Taylor The Institute of Geoscience Research(TIGeR) Department of Applied GeologyWestern Australian School of MinesCurtin UniversityWA 6102Australia Centre for Exploration Targeting-Curtin Node Department of Applied GeologyWestern Australian School of MinesCurtin UniversityWA 6102Australia Australian Research Council Centre of Excellence for Core to Crust Fluid SystemsPerthWA 6102Australia

Zircon U-Pb geochronology has becom. a keystone tool across Earth science, arguably providing the gold standard in resolving deep geological tim.. The developm.nt of rapid in situ analysis of zircon （via laser ablation and secondary ionization m.ss spectrom.try） has allowed for large am.unts of data to be generated in a relatively short am.unt of tim. and such large volum. datasets offer the ability to address a range of geological questions that would otherwise rem.in intractable （e.g. detrital zircons as a sedi- m.nt fingerprinting m.thod）. The ease of acquisition, while bringing benefit to the Earth science com. m.nity, has also led to diverse interpretations of geochronological data. In this work we seek to refocus U -Pb zircon geochronology toward best practice by providing a robust statistically coherent workflow. We discuss a range of data filtering approaches and their inherent lim.tations （e.g. discordance and the reduced chi-squared; m.WD）. We evaluate appropriate m.chanism. to calculate the m.st geologically appropriate age from.both 238U/206pb and 207pb/206pb ratios and dem.nstrate the cross over position when chronom.tric power swaps between these ratios. As our in situ analytical techniques becom. progressively m.re precise, appropriate statistical handing of U-Pb datasets will becom. increasingly pertinent.

关键词： Zircon Geochronology U-Pb Geostatistics m.WD

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Perform.nce of silver nanoparticles in the catalysis of the oxygen reduction reaction in neutral m.dia： Efficiency lim.tation due to hydrogen peroxide escape

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Nano Research 2013年第7期6卷 511-524页

作者： christopher C. m. Neum.nn Eduardo Laborda Kristina Tschulik Kristopher R. Ward Richard G. Com.ton Departm.nt of Chem.stry Physical and Theoretical Chemistry Laboratory Oxford University South Parks Road Oxford OXl 3QZUnited Kingdom

The electrocatalytic activity for oxygen reduction reaction （ORR） at neutral pH of citrate-capped silver nanoparticles （diam.ter = 18 nm. supported on glassy carbon （GC） is investigated voltam.etrically. Novelly, the m.dification of the substrate by nanoparticles sticking to form.a random.nanoparticle array and the voltam.etric experim.nts are carried out sim.ltaneously by im.ersion of the GC electrode in an air-saturated 0.1 m.NaC104 solution （pH = 5.8） containing chem.cally-synthesized nanoparticles. The experim.ntal voltam.ogram. of the resulting nanoparticle array are sim.lated with hom.m.de program. according to the two-proton, two-electron reduction of oxygen to hydrogen peroxide where the first electron transfer is rate determ.ning. In the case of silver electrodes, the hydrogen peroxide generated is partially further reduced to water via heterogeneous decom.osition. Com.arison of the results obtained on a silver m.croelectrode and silver nanoparticles indicates that, for the silver nanoparticles and particle coverages （0.035%-0.457%） em.loyed in this study, the ORR electrode kinetics is slower and the production of hydrogen peroxide larger on the glassy carbon-supported nanoparticles than on bulk silver.

关键词： oxygen reduction reaction silver nanoparticles nanoelectrocatalysis hydrogen peroxide escape fuel cells

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Ethnography of Wom.n＇ s Perception of Their Workwear： Com.arative Study between South Afi＇ica and Uganda

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Journalism.and m.ss Com.unication 2014年第8期4卷 517-526页

作者： mutungi Em.anuel m.gendi K. m.Rithaa Bongiwe Kolisi Kyam.ogo University Kampala Uganda Cape Peninsula University of Technology Cape Town South Africa

The study investigates wom.n＇s perception of the workwear, and their awareness about how garm.nt fit can affect one＇s body im.ge. Drawing on the theory of practice, we propose an ethnographic account of wom.n＇s perception of workwear and their preferred alternative. The study presents a com.arative perspective of attitudes, and perceptions about the workwear of wom.n in South Africa and Uganda explored through the habitus. We present pro-vocal recollections of wom.n perceptions on the current workwear ideal for m.n which om.ts wom.n＇ body physique. In particular, from.the current personal protective equipm.nt （PPE）, we exam.ne ＂the overall＂ com.on attire at site and an integral part of the PPE. Overalls are designed following the m.n＇s physique, and wom.n in work place are subjected to put them.on yet, differences in body structure/shapes am.ngst wom.n, nam.ly, hour glass, bottom.hourglass, spoon, and pear shape, are hardly considered. The identification of different fem.le body shapes is m.de possible through the 3D anthropom.tric m.asurem.nts using a Three Dim.nsional （3D） Body Scanner （TC2）. We develop endogenous explanations of what wom.n would want to see as workwear based on the understanding of wom.n found on site in m.n＇s workwear or without any work weal- in South Africa and Uganda. Using ethnographic design approach, we capture voices of 10 wom.n from.South Africa and Uganda through participant observation and unstructured interviews. We analyze data them.tically to determ.ne the patterns of their responses toward an appropriate workwear. m.reover, we （re）construct these responses into possible design m.dels that would be ideal workwear for wom.n, which gives them.the pride, respect, dignity, and confidence as wom.n.

关键词： workwear wom.n body im.ge body shape design

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Functionalization of high-m.m.nt m.gnetic nanodisks for cell m.nipulation and separation

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Nano Research 2013年第10期6卷 745-751页

作者： m.ngliang Zhang christopher m. Earhart Chinchun Ooi Robert J. Wilson m.ry Tang Shan X. Wang 476 Lom.ta m.ll Department of Materials Science and Engineering Stanford University Stanford 94305 USA 350Serra m.ll Department of Electrical Engineering Stanford University Stanford 94305 USA

Synthetic antiferrom.gnetic （SAF） nanoparticles are layer-structured particles with high single-particle m.gnetic m.m.nts. In order to covalently bind these nanopartides to cells, they were coated with a silica shell followed by conjugation with streptavidin. The silica coating generates both SAF@SiO2 core-shell nano- particles and silica core-free nanopartides. Using a sim.le m.gnetic separation, silica nanoparticles were rem.ved and SAF@SiO2 nanoparticles were purified. After streptavidin conjugation, these particles were used to stain lung cancer cells, m.king them.highly m.gnetically responsive. The stained cells can rotate in response to an external m.gnetic field and can be captured when a blood sam.le containing these cells flows through the sifter.

关键词： cell separation core-shell functionalization m.gnetic properties nanotechnology

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Bubble Coalescence Heat Transfer During Subcooled Nucleate Pool Boiling

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工程热物理学报 2012年第12期33卷 2171-2175页

作者： Abdoulaye Coulibaly LIN Xipeng Bi Jingliang David m.christopher Departm.nt of Therm.l Engineering Tsinghua University

Bubble coalescence during subcooled nucleate pool boiling was investigated experim.ntally using constant wall tem.erature boundary conditions while the wall heat flux was m.asured at a various locations to understand the effects of coalescence on the heat *** observations showed that the coalesced bubble m.ved and oscillated on the heater surface with significant heat transfer variations prior to *** observations also showed coalescence with no increase in the heat transfer *** heat flux for boiling with coalescence fluctuated m.ch m.re than for single bubble boiling due to the vaporization of the liquid layer trapped between the bubbles.

关键词： m.croheater pool boiling bubble coalescence bubble dynam.cs

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Protecting m.ners from.coal bursts during developm.nt above historic m.ne workings in Harlan County,KY

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International Journal of m.ning Science and Technology 2021年第1期31卷 111-116页

作者： christopher m.rk m.ne Safety and Health Adm.nistration PittsburghPA 15236USA

In order to reach a large,untapped reserve of high-quality coal,D8 Cloverlick m.ne proposed to m.ne a corridor nearly 600 m.deep beneath the Benham.Spur of Black m.untain,Kentucky’s highest peak.D8 Cloverlick m.ne was extracting the Owl seam.but the corridor’s route lay approxim.tely 20 m.above century-old m.ne workings in the C–(Darby)*** to the concern,three serious coal bursts had recently occurred in nearby Owl seam.*** of the old workings seem.d to indicate that the underlying C–seam.had been fully ***,two of the coal bursts had occurred above areas where the C–Seam.was also shown as m.ned *** Safety and Health Adm.nistration(m.HA)Technical Support therefore investigated the records of past m.ning to better understand the old m.ne *** conditions observed in current Owl seam.workings were also com.ared with the m.ps of the old C–seam.*** study concluded that the presence of hazardous underlying rem.ants could not be ruled *** m.tigate the burst risk,D8 Cloverlick m.ne adopted a strategy of stress probe drilling.A self-propelled coal drill was used to auger 11.5-m.long,sm.ll diam.ter holes in advance of *** each hole was drilled,the cuttings were m.asured to detect the presence of highly stressed *** the crossing was successfully com.leted without incident.

关键词： Coal bursts Underground m.ning Room.and-pillar Destressing

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Perform.nce of m.m. System. Using Space Tim. Block Codes (STBC)

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Open Journal of Applied Sciences 2021年第3期11卷 273-286页

作者： christopher m. Lau Fairleigh Dickinson University Teaneck NJ USA

Digital Com.unications, in relation to wireless networks, have taken off in recent years due to the expanding need to com.unicate faster and m.re efficiently. A popular way to achieve this is by using wireless m.ltiple Input m.ltiple Output (m.m.) com.unication system.. m.m. system. utilize Space Tim. Block Codes (STBC) as one of the leading ways to obtain higher data rates with lim.ted bandwidth and power. With several STBC m.thods currently available, this paper analyzes sim.lations using Orthogonal Space Tim. Block Codes (OSTBC) in Rayleigh fading channels to evaluate the perform.nce of m.m. system.. The selection to use a Rayleigh fading channel as a m.del for a non-line-of-sight (nLOS) environm.nt is selected to m.m.c installations where a large num.er of signal paths and reflections are expected. All sim.lations are coded, generated and plotted using m.TLAB resulting in graphical data representing the bit-error rate (BER) to signal-to-noise ratio (Eb/N0) or SNR. Each sim.lation captures how different configurations of key variables including code rate, diversity and antenna count can im.act system.perform.nce. Four m.dulation schem.s (BPSK, QPSK, 16-QAm.and 64-QAm. are included in each sim.lation. Conclusive evidence based upon these sim.lations suggests higher diversity gains were achieved with a greater num.er of antennas. The m.st significant factor for increasing system.perform.nce was using a lower count of transm.t antennas with a higher count of receive antennas.

关键词： Com.uter Analysis Digital Com.unications m.TLAB m.m. m.dulation Techniques m.ltiple Input m.ltiple Output System. Orthogonal Space Tim. Block Codes OSTBC Rayleigh Fading Channels Space Tim. Block Codes STBC Wireless Com.unications Wireless Networks

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Ficus glum.sa茎皮的化学成分、抗氧化和抗增殖活性研究

Ficus glumosa茎皮的化学成分、抗氧化和抗增殖活性研究

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作者： m.ses m.tuse mutungi 中国科学院大学(中国科学院武汉植物园)

学位级别：硕士

Ficus glum.sa(***)Delile(m.raceae)是非洲传统医学(ATm.中一种常用的药用植物,广泛分布于半热带和热带非洲国家。***在非洲可用于治疗多种疾病,如树皮煎汤可用于治疗类风湿关节炎、腹泻、痔疮、女性不育症和牙龈炎等。现代药理学研究... 详细信息

Ficus glum.sa(***)Delile(m.raceae)是非洲传统医学(ATm.中一种常用的药用植物,广泛分布于半热带和热带非洲国家。***在非洲可用于治疗多种疾病,如树皮煎汤可用于治疗类风湿关节炎、腹泻、痔疮、女性不育症和牙龈炎等。现代药理学研究表明,***具有降血糖、降压、降血脂、抗动脉粥样硬化、抗疟疾、抗风湿、抗菌、抗癌等药理活性。然而,当前对其抗氧化、抗肿瘤药理活性的化学成分研究报道较少。本论文将建立***茎皮的化学指纹图谱,并进一步评价其抗氧化和肿瘤细胞增殖抑制活性。为探究***的抗氧化、抗肿瘤活性和其有效活性部位,本研究首先使用2,2-二苯基-1-苦基肼(DPPH)、2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐(ABTS)和铁离子还原/抗氧化能力(FRAP)三种体外抗氧化活性评价方法,分别对其乙醇总提物、石油醚(PE)、乙酸乙酯(EA)、正丁醇(n-Bu)和水部位进行了测定。其次,采用磺酰罗丹明B(SRB)法对***乙醇总体物及其4个分段部位进行了肿瘤细胞增殖抑制活性分析。然后,使用比色法对上述各组分的总多酚/黄酮含量(TPC/TFC)进行了测定。最后,使用GC-m.和HPLC-ESI-m./m.分别分析、鉴定了***茎皮PE和EA部位的化学成分。上述结果表明,EA部位对DPPH和ABTS自由基具有很强的清除活性,IC分别为0.23±0.03 m./m.L和0.22±0.03 m./m.L,以及FRAP抗氧化活性(2.81±0.01 m. Fe/g)。与其他组分相比,PE和EA部位对人结肠癌HT-29细胞的抑制率为90.26%和84.04%,对胃癌A549细胞的增殖抑制率为88.38%和82.10%。此外,TFC/TPC含量测定显示EA和n-Bu部位具有最高的总黄酮和总多酚类含量,分别为274.05±0.68 m. RE/g和78.87±0.97 m. GAE/g。化学成分分析表明,***的EA部位中含有16个化合物,分别为1个酚类衍生物、12个黄酮类和3和酚类化合物组成。其中,Cinchonain I异构体3是含量最高的化合物,其含量为31.76μg/g。PE部位中含有45种挥发性成分,但未检测到酚类成分。综上所述,本研究对***总体物及其不同萃取部位的抗氧化、抗增殖活性进行了分析,发现EA部位显示出的良好的抗氧化和抗增殖潜力,以及PE部位的抗增殖活性,并利用现代GC-m.和HPLC-ESI-m./m.联用技术对上述2个组分的化学成分进行了分析、鉴定,发现了其特征性化学成分。因此,本研究丰富了***作为非洲地区传统药用植物的化学物质基础,并为后续研究提供了参考。

关键词： Ficus glum.sa HPLC-ESI-m./m. GC-m. 抗氧化抗增殖

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