Transmission resonance in a composite plasmonic structure

The design, fabrication, and optical properties of a composite plasmonic structure, a two-dimentional array of split-ring resonators inserted into periodic square holes of a metal film, have been reported. A new type of transmission resonance, which makes a significant difference from the conventional peaks, has been suggested both theoretically and experimentally. To understand this effect, a mechanism of ring- resonance induced dipole emission is proposed.Comment: 14 pages, 4 figure

Transcriptional Regulation of Neuroectodermal Lineage Commitment in Embryonic Stem Cells

Lineage commitment of pluripotent cells is a critical step in the development of multicellular organisms and a prerequisite for efficient differentiation of stem cells into terminal cell types. During successful neuroectodermal lineage commitment, extracellular signals terminate the pluripotency program, activate neural transcriptional program, and suppress alternative mesendodermal fate. Retinoic acid (RA) has been identified as a potent inducer of neural differentiation in embryonic stem cells (ESCs), yet the transcriptional program initiated by RA is poorly understood. Expression profiling of differentiating ESCs revealed delayed response of the pluripotency marker Oct4 and neural marker Sox1 following RA treatment, suggesting that RA regulates the pluripotency program and neural transcriptional program indirectly through induction of additional transcription factors. In this study, I identified a zinc finger factor Zfp703 as a downstream effector of RA-mediated neuroectodermal lineage commitment. Zfp703 expression in ESCs resulted in Oct4 repression, Sox1 induction, and neural differentiation. Moreover, Zfp703 strongly suppresses mesendodermal fate by repressing genes such as Brachyury, Eomes, and Mixl1 even under conditions favoring mesendoderm specification. Zfp703 binds to and represses Lef1 promoter, raising the possibility that it might modulate Wnt signaling via regulating Lef1. Finally, Zfp703 is not required for RA-mediated Oct4 repression and Sox1 induction. However, it is necessary for efficient Brachyury repression by RA. Based on these data, I propose that Zfp703 is involved in the transcription regulation during neural progenitor specification. Through downregulating of both mesendodernal fate and pluripotency, Zfp703 de-represses neural transcriptional program and indirectly promotes the default neuroectodermal lineage commitment

Real-time Data Flow Control for CBM-TOF Super Module Quality Evaluation

Super module assembled with MRPC detectors is the component unit of TOF (Time of Flight) system for the Compressed Baryonic Matter (CBM) experiment. Quality of super modules needs to be evaluated before it is applied in CBM-TOF. Time signals exported from super module are digitalized at TDC (Time to Digital Converter) station. Data rate is up to 6 Gbps at each TDC station, which brings a tremendous pressure for data transmission in real time. In this paper, a real-time data flow control method is designed. In this control method, data flow is divided into 3 types: scientific data flow, status data flow and control data flow. In scientific data flow, data of each TDC station is divided into 4 sub-flows, and then is read out by a parallel and hierarchical network, which consists of multiple readout mother boards and daughter boards groups. In status data flow, status data is aggregated into a specific readout mother board. Then it is uploaded to DAQ via readout daughter board. In control data flow, control data is downloaded to all circuit modules in the opposite direction of status data flow. Preliminary test result indicated data of STS was correctly transmitted to DAQ with no error and three type data flows were control orderly in real time. This data flow control method can meet the quality evaluation requirement of supper module in CBM-TOF