9,659 research outputs found

    Emergence of synchronization induced by the interplay between two prisoner's dilemma games with volunteering in small-world networks

    Full text link
    We studied synchronization between prisoner's dilemma games with voluntary participation in two Newman-Watts small-world networks. It was found that there are three kinds of synchronization: partial phase synchronization, total phase synchronization and complete synchronization, for varied coupling factors. Besides, two games can reach complete synchronization for the large enough coupling factor. We also discussed the effect of coupling factor on the amplitude of oscillation of cooperatorcooperator density.Comment: 6 pages, 4 figure

    Multi-channel SPR biosensor based on PCF for multi-analyte sensing applications

    Get PDF
    This paper presents a theoretical investigation of a novel holey fiber (Photonic Crystal Fiber (PCF)) multi-channel biosensor based on surface plasmon resonance (SPR). The large gold coated micro fluidic channels and elliptical air hole design of our proposed biosensor aided by a high refractive index over layer in two channels enables operation in two modes; multi analyte sensing and self-referencing mode. Loss spectra, dispersion and detection capability of our proposed biosensor for the two fundamental modes (HE x 11 and HE y 11 ) have been elucidated using a Finite Element Method (FEM) and Perfectly Matching Layers (PML)

    Detection of subthreshold pulses in neurons with channel noise

    Full text link
    Neurons are subject to various kinds of noise. In addition to synaptic noise, the stochastic opening and closing of ion channels represents an intrinsic source of noise that affects the signal processing properties of the neuron. In this paper, we studied the response of a stochastic Hodgkin-Huxley neuron to transient input subthreshold pulses. It was found that the average response time decreases but variance increases as the amplitude of channel noise increases. In the case of single pulse detection, we show that channel noise enables one neuron to detect the subthreshold signals and an optimal membrane area (or channel noise intensity) exists for a single neuron to achieve optimal performance. However, the detection ability of a single neuron is limited by large errors. Here, we test a simple neuronal network that can enhance the pulse detecting abilities of neurons and find dozens of neurons can perfectly detect subthreshold pulses. The phenomenon of intrinsic stochastic resonance is also found both at the level of single neurons and at the level of networks. At the network level, the detection ability of networks can be optimized for the number of neurons comprising the network.Comment: 14 pages, 9 figure

    A duplex real-time RT-PCR assay for detecting H5N1 avian influenza virus and pandemic H1N1 influenza virus

    Get PDF
    A duplex real-time reverse transcriptase polymerase chain reaction (RT-PCR) assay was improved for simultaneous detection of highly pathogenic H5N1 avian influenza virus and pandemic H1N1 (2009) influenza virus, which is suitable for early diagnosis of influenza-like patients and for epidemiological surveillance. The sensitivity of this duplex real-time RT-PCR assay was 0.02 TCID50 (50% tissue culture infective dose) for H5N1 and 0.2 TCID50 for the pandemic H1N1, which was the same as that of each single-target RT-PCR for pandemic H1N1 and even more sensitive for H5N1 with the same primers and probes. No cross reactivity of detecting other subtype influenza viruses or respiratory tract viruses was observed. Two hundred and thirty-six clinical specimens were tested by comparing with single real-time RT-PCR and result from the duplex assay was 100% consistent with the results of single real-time RT-PCR and sequence analysis

    Ionophore‐Based Biphasic Chemical Sensing in Droplet Microfluidics

    Full text link
    Droplet microfluidics is an enabling platform for high‐throughput screens, single‐cell studies, low‐volume chemical diagnostics, and microscale material syntheses. Analytical methods for real‐time and in situ detection of chemicals in the droplets will benefit these applications, but they remain limited. Reported herein is a novel heterogeneous chemical sensing strategy based on functionalization of the oil phase with rationally combined sensing reagents. Sub‐nanoliter oil segments containing pH‐sensitive fluorophores, ionophores, and ion‐exchangers enable highly selective and rapid fluorescence detection of physiologically important electrolytes (K+, Na+, and Cl−) and polyions (protamine) in sub‐nanoliter aqueous droplets. Electrolyte analysis in whole blood is demonstrated without suffering from optical interference from the sample matrix. Moreover, an oil phase doped with an aza‐BODIPY dye allows indication of H2O2 in the aqueous droplets, exemplifying sensing of targets beyond ionic species.Phase in: The oil phase in droplet microfluidics is functionalized with rationally combined sensing reagents. Thus, the sub‐nanoliter oil segments become chemical sensors toward specific targets in their adjacent sub‐nanoliter aqueous droplets. This biphasic sensing platform enables detection of a wide spectrum of targets including ionic, polyionic, and non‐ionic species, in a real‐time and reagent‐conservative fashion.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149501/1/anie201902960_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149501/2/anie201902960-sup-0001-misc_information.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149501/3/anie201902960.pd

    Gamma-Ray Burst Sequences in Hardness Ratio-Peak Energy Plane

    Full text link
    The narrowness of the distribution of the peak energy of ÎœFÎœ\nu F_{\nu} spectrum of gamma-ray bursts (GRBs) and the unification of GRB population are great puzzles yet to be solved. We investigate the two puzzles based on the global spectral behaviors of different GRB population in the HR−EpHR-E_{\rm{p}} plane (HR the spectral hardness ratio) with BATSE and HETE-2 observations. It is found that long GRBs and XRFs observed by HETE-2 seem to follow the same sequence in the HR−EpHR-E_{\rm{p}} plane, with the XRFs at the low end of this sequence. The long and short GRBs observed by BATSE follow significantly different sequences in the HR−EpHR-E_{\rm p} plane, with most of the short GRBs having a larger hardness ratio than the long GRBs at a given EpE_{\rm{p}}. These results indicate that the global spectral behaviors of the long GRB sample and the XRF sample are similar, while that of short GRBs is different. The short GRBs seem to be a unique subclass of GRBs, and they are not the higher energy extension of the long GRBs (abridged).Comment: 9 pages, 3 figure

    Degradation of structure and properties of rail surface layer at long-term operation

    Get PDF
    The microstructure evolution and properties variation of the surface layer of rail steel after passed 500 and 1000 million tons of gross weight (MTGW) have been investigated. The wear rate increases to 3 and 3.4 times after passed 500 and 1000 MTGW, respectively. The corresponding friction coefficient decreases by 1.4 and 1.1 times. The cementite plates were destroyed and formed the cementite particles of around 10-50 nm in size after passed 500 MTGW. The early stage dynamical recrystallization was observed after passed 1000 MTGW. The mechanisms for these have been suggested. The large number of bend extinction contours is revealed in the surface layer. The internal stress field is evaluated
    • 

    corecore