Effects of different cue positions on evoked potentials in the cerebral cortex during global and local processing of compound stimuli A study of event-related potential

BACKGROUND： Previous studies of attentional control have focused primarily on pre-cue control of attentional cue and direction. OBJECTIVE： To measure the differences in electrical activity of brain cells while processing pre-cue and post-cue compound stimuli, and to explore brain electrical activity during global and local processing of compound stimuli according to electroencephalogram （EEG） recordings. DESIGN, TIME AND SETTING： A within-subject design study was performed at the School of Psychology, State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, China from March to May 2006. PARTICIPANTS： A total of 30 healthy, undergraduate students, aged 17-24 years, comprising 12 males and 18 females, were voluntarily enrolled from Beijing Normal University. Subjects exhibited normal or corrected-to-normal visual acuity. No significant non signal wave drift was detected during testing. METHODS： A total of 30 subjects were subjected to pre-cue and post-cue compound stimulus processing using event-related potential and EEG recordings. MAIN OUTCOME MEASURES： Evoked potential was recorded in different brain regions utilizing event-related potential to observe hemispheric symmetry, cue consistency and global-local features. RESULTS： Pre-cue compound stimuli resulted in hemispheric asymmetry for early wave （N1） and late wave （P3） in anterior brain regions. Early- and late-wave induced hemispheric asymmetry for electrode points （O1, 02, P3, P4, Pz, F3, F4, F7, F8, Fz, FP1, FP2, T7, TS, C3, C4, and Cz） during processing of pre-cue compound stimuli （P 〈 0.05）. Post-cue compound stimuli did not induce hemispheric asymmetry of brain waves induced by the above-described electrode points. No significant differences in global and local responses were determined during processing of post-cue compound stimuli. Under pre-cue conditions, significant differences were observed in N1 and P3 in the above-mentioned electrode points （P 〈 0.05）. However, under post-cue conditions, no significant differences were observed in N1 and P3 using the above-mentioned electrode points. Significant differences in early waves （N1 and P1） using the above-mentioned electrode points were detected between anterior and posterior brain regions, regardless of consistent or inconsistent, large or small letters （P 〈 0.05）. CONCLUSION： Cue location effected mechanisms underlying global and local processing of compound stimuli. Pre- or post-cue conditions resulted in differences in hemispheric symmetry, cue consistency, and global and local features. Under pre-cue conditions, hemispheric dominance was detected in global and local processing following compound stimuli. Under post-cue conditions, hemispheric dominance was not determined.

Multiplexed Metasurfaces for High-Capacity Printing Imaging

We successfully overcome the problem of cross-talk in multiplexed metasurface design and realize the multiplexed metasurface with five printing images in both theoretical and experimental aspects,by employing the coherent pixel design considering coherent superposition of all the sub-elements.Compared with most previous studies where the integrated printing images were usually no more than three,our study shows obvious improvement.More importantly,in our approach all the sub-elements,which were crystalline silicon nanobricks with the size of 320×80×230 nm^3,were arranged in a square space of 1.45×1.45μm^2 following the closest packing way,enabling our multiplexed metasurface to have a potential of effective physical information capacity of printing image reaching the optical diffraction limit.Our study not only enlarges the information capacity of metasurfaces by expanding the integrated number of printing image in one metasurface,but also can promote metasurface applications in various fields such as information storage and encoding.

Multiplexed manipulation of orbital angular momentum and wavelength in metasurfaces based on arbitrary complex-amplitude control

Due to its unbounded and orthogonal modes,the orbital angular momentum(OAM)is regarded as a key optical degree of freedom(DoF)for future information processing with ultra-high capacity and speed.Although the manipulation of OAM based on metasurfaces has brought about great achievements in various fields,such manipulation currently remains at single-DoF level,which means the multiplexed manipulation of OAM with other optical DoFs is still lacking,greatly hampering the application of OAM beams and advancement of metasurfaces.In order to overcome this challenge,we propose the idea of multiplexed coherent pixel(MCP)for metasurfaces.This approach enables the manipulation of arbitrary complex-amplitude under incident lights of both plane and OAM waves,on the basis of which we have realized the multiplexed DoF control of OAM and wavelength.As a result,the MCP method expands the types of incident lights which can be simultaneously responded by metasurfaces,enriches the information processing capability of metasurfaces,and creates applications of information encryption and OAM demultiplexer.Our findings not only provide means for the design of high-security and high-capacity metasurfaces,but also raise the control and application level of OAM,offering great potential for multifunctional nanophotonic devices in the future.

Color-selective three-dimensional polarization structures

Polarization as an important degree of freedom for light plays a key role in optics.Structured beams with controlled polarization profles have diverse applications,such as information encoding,display,medical and biological imaging,and manipulation of microparticles.However,conventional polarization optics can only realize two-dimensional polarization structures in a transverse plane.The emergent ultrathin optical devices consisting of planar nanostructures,so-called metasurfaces,have shown much promise for polarization manipulation.Here we propose and experimentally demonstrate color-selective three-dimensional(3D)polarization structures with a single metasurface.The geometric metasurfaces are designed based on color and phase multiplexing and polarization rotation,creating various 3D polarization knots.Remarkably,different 3D polarization knots in the same observation region can be achieved by controlling the incident wavelengths,providing unprecedented polarization control with color information in 3D space.Our research findings may be of interest to many practical applications such as vector beam generation,virtual reality,volumetric displays,security,and anti-counterfeiting.

Integrating lattice and gap plasmonic modes to construct dual-mode metasurfaces for enhancing light–matter interaction

Photonic structures with optical resonances beyond a single controllable mode are strongly desired for enhancing light±matter interactions and bringing about advanced photonic devices. However, the realization of effective multimodal photonic structures has been restricted by the limited tunable range of mode manipulation, the spatial dispersions of electric fields or the polarization-dependent excitations. To overcome these limitations, we create a dualmode metasurface by integrating the plasmonic surface lattice resonance and the gap plasmonic modes;this metasurface offers a widely tunable spectral range, good overlap in the spatial distribution of electric fields, and polarization independence of excitation light. To show that such dual-mode metasurfaces are versatile platforms for enhancing light±matter interactions, we experimentally demonstrate a significant enhancement of second-harmonic generation using our design, with a conversion efficiency of 1±3 orders of magnitude larger than those previously obtained in plasmonic systems. These results may inspire new designs for functional multimodal photonic structures.

Transcriptome and genome analysis to identify C2H2 genes participating in low-temperature conditioning-alleviated postharvest chilling injury of peach fruit

Objectives:This work intended to identify candidate C2H2 genes participating in low-temperature conditioning(LTC)-alleviated postharvest chilling injury of peach fruit.Materials and Methods:For LTC treatment,fruit were pre-stored at 10℃for 5 d and then transferred to 0℃storage.Fruit firmness was measured by a hardness tester.H_(2)O_(2)content was determined by luminosity measurement model using a multifunctional enzyme labeler.Identification of C2H2 family members was performed by HMMSCAN according to peach genome.The cis-acting element of gene promoters was analyzed using the Plant CARE website.Weighted gene coexpression network analysis(WGCNA)was performed by the WGCNA package in the BMK Cloud platform.Results:LTC treatment decreased flesh browning rate and H_(2)O_(2)production of‘Beijing No.9’peach.Transcription factor identification of differentially expressed genes in 0℃and the LTC treatment indicated that peach C2H2 participated in the regulation of chilling injury.A total of 47 C2H2 genes were identified based on peach genome.Real-time quantitative polymerase chain reaction(qRT-PCR),phylogenetic analysis and promoter cis-acting element analysis revealed that ZFP21 was involved in the regulation of LTC-alleviated chilling injury in peach.WGCNA and dual luciferase assay suggested that ZFP21 participated in LTC-alleviated chilling injury by downregulating the expression of reactive oxygen species-related genes Rboh.Conclusions:Our investigation,based on genome and RNA-seq,revealed that ZFP21 was involved in LTC treatment-alleviated chilling injury of peach fruit.This work is useful for the identification of peach cold tolerance-related genes and the study of C2H2 family in peach.

当有些东西用钱买不到的时候:一项关于多投标人跨境收购拍卖的研究（英文）

本文研究不同国家的跨国投标人的收购行为,他们往往为了收购一个目标公司成为彼此的竞争者。拍卖的规则是,给出最高价格的投标人理所当然地获得胜利。然而,我们的实证证据表明,企业为了并购,不能仅仅通过抬高价格赢得竞争性拍卖。首先,我们采用交易成本理论来描绘跨国投标人拍卖活动的复杂性、不确定性和机会成本。其次,我们认为,目标企业会降低交易成本,评估投标人的一些价格以外的因素。我们从知识基础观点和制度理论来确定这些非金融变量。我们发现,相对较新的机构,投标人和目标公司之间的距离减少了胜利的机会,尽管投标人出价很高;而相对实力相当的机构和投标人相关的经验增加了中标概率,尽管价格略低。因此,企业不能仅依靠支付给目标公司股东一大笔钱就能成功地进行国际收购。相反,他们还需要克服外来责任,获得合法性,并展示相关的能力,以便在国际上多个拍卖中取得成功。我们的论文率先推出跨境拍卖管理文献和实证证明事务的应用程序,因为我们是基于经济学、制度理论和KBV的背景提出的。