15 research outputs found

    Nonlinear eco-evolutionary games with global environmental fluctuations and local environmental feedbacks

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    Environmental changes play a critical role in determining the evolution of social dilemmas in many natural or social systems. Generally, the environmental changes include two prominent aspects: the global time-dependent fluctuations and the local strategy-dependent feedbacks. However, the impacts of these two types of environmental changes have only been studied separately, a complete picture of the environmental effects exerted by the combination of these two aspects remains unclear. Here we develop a theoretical framework that integrates group strategic behaviors with their general dynamic environments, where the global environmental fluctuations are associated with a nonlinear factor in public goods game and the local environmental feedbacks are described by the `eco-evolutionary game'. We show how the coupled dynamics of local game-environment evolution differs in static and dynamic global environments. In particular, we find the emergence of cyclic evolutions of group cooperation and local environment, which forms an interior irregular loop in the phase plane, depending on the relative changing speed of both global and local environments compared to the strategic change. Our results provide important insights toward how diverse evolutionary outcomes could emerge from the nonlinear interactions between strategies and the changing environments

    Numerical study of inflow equivalence ratio inhomogeneity on oblique detonation formation in hydrogen-air mixtures

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    In this study, numerical simulations using Euler equations with detailed chemistry are performed to investigate the effect of fuel-air composition inhomogeneity on the oblique detonation wave (ODW) initiation in hydrogen-air mixtures. This study aims for a better understanding of oblique detonation wave engine performance under practical operating conditions, among those is the inhomogeneous mixing of fuel and air giving rise to a variation of the equivalence ratio (ER) in the incoming combustible flow. This work focuses primarily on how a variable equivalence ratio in the inflow mixture affects both the formation and characteristic parameters of the oblique detonation wave. In this regard, the present simulation imposes initially a lateral linear distribution of the mixture equivalence ratio within the initiation region. The variation is either from fuel-lean or fuel-rich to the uniform stoichiometric mixture condition above the oblique shock wave. The obtained numerical results illustrate that the reaction surface is distorted in the cases of low mixture equivalence ratio. The so-called ā€œV-shapedā€ flame is observed but differed from previous results that it is not coupled with any compression or shock wave. Analyzing the temperature and species density evolution also shows that the fuel-lean and fuel-rich inhomogeneity have different effects on the combustion features in the initiation region behind the oblique shock wave. Two characteristic quantities, namely the initiation length and the ODW surface position, are defined to describe quantitatively the effects of mixture equivalence ratio inhomogeneity. The results show that the initiation length is mainly determined by the mixture equivalence ratio in the initiation region. Additional computations are performed by reversing ER distribution, i.e., with the linear variation above the initiation region of uniform stoichiometric condition and results also demonstrate that the ODW position is effectively determined by the ER variation before the ODW, which has in turn only negligible effect on the initiation length

    Robust estimation of bacterial cell count from optical density

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    Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

    Hybrid Structure Multichannel All-Fiber Current Sensor

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    We have experimentally developed a hybrid-structure multi-channel all-fiber current sensor with ordinary silica fiber using fiber loop architecture. According to the rationale of time division multiplexing, the sensor combines parallel and serial structures. The purpose of the hybrid-structure multi-channel all-fiber current sensor is to get more information from the different measured points simultaneously. In addition, the hybrid-structure fiber current sensor exhibited a good linear response for each channel. A three-channel experiment was performed in the study and showed that the system could detect different current positions. Each channel could individually detect the current and needed a separate calibration system. Furthermore, the three channels will not affect each other

    Relationships between progrosis, immune infiltration and expression of SMYD3 in pan-cancer

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    Objective The study focuses on the prognostic value of SMYD3 in pan cancer, and analyze the influence of SMYD3 on tumor tissue immune infiltration. Methods The gene expression and protein density data were collected from TCGA, GTEx and HPA databases. Kaplan-Meier(KM) algorithm was used to evaluate the impact of SMYD3 on the prognosis of patients with different kinds of tumor. The ESTIMATE algorithm and Timer database were applied to investigate the relationship between SMYD3 and immune microenvironment. And the results were verified in B16 cell line by knockout SMYD3. Results Higher expression of SMYD3 was observed in tumor tissue than normal tissue in both mRNA and protein level. And SMYD3 was thought to be associated with worse outcomes of patients(PPSmyd3 in B16 cell line increased the expression of antigen present genes(PConclusions Smyd3 is an important gene related to the prognosis of patients and the antigen presentation function of tumor cells. Smyd3 can inhibit the infiltration of immune cell by down-regulation of antigen-present genes, which induces the immune escape

    Overlap Spectrum Fiber Bragg Grating Sensor Based on Light Power Demodulation

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    Demodulation is a bottleneck for applications involving fiber Bragg gratings (FBGs). An overlap spectrum FBG sensor based on a light power demodulation method is presented in this paper. The demodulation method uses two chirp FBGs (cFBGs) of which the reflection spectra partially overlap each other. The light power variation of the overlap spectrum can be linked to changes in the measurand, and the sensor function can be realized via this relationship. A temperature experiment showed that the relationship between the overlap power spectrum of the FBG sensor and temperature had good linearity and agreed with the theoretical analysis

    A Loop All-Fiber Current Sensor Based on Single-Polarization Single-Mode Couplers

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    Low current sensitivity and insufficient system stability are two key problems in all-fiber current sensor (AFCS) studies. In order to solve the two problems, a novel AFCS combining single-polarization single-mode (SPSM) couplers and a loop structure is presented in this paper with a design that incorporates the advantages of both SPSM couplers and a loop structure. SPSM couplers are shown to simplify the AFCS system and reduce the risk of interference, and the loop structure can enhance the current sensitivity. Both theory and experiment prove that the new AFCS can simultaneously overcome two prevalent obstacles of low current sensitivity and low stability

    Infrared Signature of the Early Stage Microsolvation in the NaSO<sub>4</sub><sup>ā€“</sup>(H<sub>2</sub>O)<sub>1ā€“5</sub> Clusters: A Simulation Study

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    Infrared photon dissociation (IRPD) spectra of the NaSO<sub>4</sub><sup>ā€“</sup>(H<sub>2</sub>O)<sub><i>n</i></sub> clusters with up to five water molecules have been studied using quantum chemical calculations. Our calculation reveals that the splitting of the peaks in the āˆ¼800ā€“1300 cm<sup>ā€“1</sup> region of the IRPD spectra, which contains the information on Sā€“O bond stretching of the anion, indicates the deviation of the cation from the <i>C</i><sub>3<i>v</i></sub> axis as well as the asymmetric distribution of the water molecules. The frequency of the H-bonded Oā€“H stretching peak in the āˆ¼2300ā€“3000 cm<sup>ā€“1</sup> window, on the other hand, provides information on the position of the newly added water molecule with respect to the cation. The IRPD technique thus provides abundant structural information on the early stage of the microsolvation and has the potential to become a powerful tool complementary to photoelectron spectroscopy
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