1,452 research outputs found

    Identification of Multiple Functional Receptors for Tyramine on an Insect Secretory Epithelium

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    The biogenic amine tyramine (TA) regulates many aspects of invertebrate physiology and development. Although three TA receptor subtypes have been identified (TAR1-3), specific receptors have not been linked to physiological responses in native tissue. In the Malpighian (renal) tubule of Drosophila melanogaster, TA activates a transepithelial chloride conductance, resulting in diuresis and depolarization of the transepithelial potential. In the current work, mutation or RNAi-mediated knockdown in the stellate cells of the tubule of TAR2 (tyrR, CG7431) resulted in a dramatic reduction, but not elimination, of the TA-mediated depolarization. Mutation or knockdown of TAR3 (tyrRII, CG16766) had no effect. However, deletion of both genes, or knockdown of TAR3 on a TAR2 mutant background, eliminated the TA responses. Thus while TAR2 is responsible for the majority of the TA sensitivity of the tubule, TAR3 also contributes to the response. Knockdown or mutation of TAR2 also eliminated the response of tubules to the related amine octopamine (OA), indicating that OA can activate TAR2. This finding contrasts to reports that heterologously expressed TAR2 is highly selective for TA over OA. This is the first report of TA receptor function in a native tissue and indicates unexpected complexity in the physiology of the Malpighian tubule

    Analysing the contagion effect and governance strategy of corporate financialisation based on a SIRS model

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    Recently, the phenomenon of economic ‘moving from reality to virtual’ has attracted widespread attention. Based on the principle of infectious disease dynamics, this study constructs a SIRS model to examine the contagion effect of corporate financialisation. Using Chinese manufacturing companies as samples, we verify the contagion of corporate financialisation before performing a simulation analysis and proposing strategies to address financial contagion risks. The results shows that corporate financialisation is contagious in the sample companies. This feature depends on the initial contagion conditions and threshold. When the degree of corporate financialisation does not meet the initial contagion conditions and is within the contagion threshold, contagion will not occur. Otherwise, financialisation behaviour will cause mutual contagion and produce a contagious effect. Meanwhile, the higher the contagion and the second conversion rates of financialisation, the stronger the contagion effect. The larger the financial reversal and self-recovery rates, the weaker the contagion effect. Finally, we propose Multi-dimensional governance strategies of financial contagion risk. This study explores the formation mechanism of corporate financialisation from a new perspective to provide ideas for the financial governance of enterprises and promote benign interaction between entities and finance

    Eeg experimental study on the infl uence of learning activity design on learning effect

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    With the rapid development of new media, online learning has become an indispensable form of educational practice all over the world. A large number of studies and practices have shown that the gamifi cation of online learning has improved students’ engagement and attention to a certain extent, but there are still some problems in some aspects. This study intends to use EEG interaction technology to monitor students’ learning situation in real time, and study the infl uence of diff erent learning activity designs on students’ learning effi ciency and continuous learning willingness through the design of diff erent elements of learning activities, such as learning knowledge density design and knowledge quantity design. To further understand the learning effi ciency and continuous learning willingness of students when they participate in diff erent learning activities, propose and verify the relationships and principles between diff erent parameters, and provide scientifi c methods and theoretical basis for the design of gamifi ed education system

    Research on the Artillery Shell Motion Parameters Automatic Detection Technology Based on Image Processing

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    AbstractTo realize automatic test of the shell motion parameters in the artillery experiment, the digital high-speed camera is used to gather the shell motion images. By applying digital image processing technique the characteristic images of shell are extracted accurately. Combined with the measuring principle of the shell motion parameters, a image test system is designed and realized automatic test of the shell motion parameters. The test results of shell motion images indicated that, the image extraction algorithm presented in this paper is easy to use and universal, and the precision of data measurement is increased. At present, the image test system has been applied in the data analysis in the artillery experiment and obtained good performance

    Discussions on the Environmental Strategies of SMEs

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    Environmental issues have become the focal point of society. However, China enterprises have not paid enough attention to environmental issues, especially those of SMEs. In this paper, it points out that environmental issues of SMEs are imperative. By analyzing the restrictive factors, we puts forward four environment strategies based on internal capability and the pollution degree of the enterprises and analyze each strategy in details

    Morphology and ultrastructure of salivary glands of male treehopper Tricentrus brunneus Funkhouser (Hemiptera: Membracoidea)

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    The salivary glands of male treehopper Tricentrus brunneus Funkhouser comprise a pair of acinous principal glands each with an anterior lobe and a posterior lobe; a pair of elbow-shaped accessory glands. Every accessory gland connects with the principal gland via a thin accessory salivary duct. The anterior lobe contains three types of acini (I, II and III), whereas the posterior lobe possesses only one type of acinus (IV). Two efferent salivary ducts fuse into a common salivary duct. Different acinis cells are filled with secretory granules that are distinct in size, number, shape and electron-density, indicating a maturation process before secreted. Infoldings in different acini suggest dilution of substances before being secreted. The presence of microvilli in acinus IV and the accessory gland duct possibly indicates the undergoing maturation of secretions. Electron-dense fine granules existed in the accessory gland cells, possibly related to virus transmission