78 research outputs found

    Larval nutrition-induced plasticity affects reproduction and gene expression of the ladybeetle, Cryptolaemus montrouzieri

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    Background: Organisms may develop into multiple phenotypes under different nutritional environments by developmental plasticity, whereas the potential costs and mechanisms of such plasticity are poorly understood. Here we examined the fitness and gene expression of nutrition-induced phenotypes in the ladybeetle, Cryptolaemus montrouzieri after having experienced varying larval food regimes. Results: We found that C. montrouzieri adults undergoing a variable larval food regime achieved a similar developmental time, survival, body mass and egg production as those undergoing a high larval food regime. The survival, developmental time, body mass and fecundity of the adults from a restricted larval food regime were inferior to those from the high and variable larval food regimes. However, the adults from this restricted larval food regime had a higher expression level of genes encoding immune-and antioxidant-related enzymes than those from the high and variable larval food regimes when exposed to starvation and pesticide conditions in adult life. Conclusions: These results suggest that larval food availability in C. montrouzieri not only triggers adult phenotypic differences but also affects reproduction and expression level of genes in adult life, indicating that the larval nutritional conditions can affect adult fitness and resistance to stressful conditions through developmental plasticity

    Effect of retrograde condensation and stress sensitivity on properties of condensate gas reservoirs

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    In the production process of low permeability condensate gas reservoir, the reverse condensate action and stress sensitivity will lead to the decrease of reservoir permeability and gas well productivity. However, there are few studies on the effect of retrograde condensation and stress sensitivity on permeability. In this study, the stress-sensitive experiments using the method with constant confining pressure but variable inner pressure were carried out on three cores from the BZ gas field in southwestern Bohai Sea. The test result that use the nitrogen as the experimental fluid represent the effect of core skeleton damage on reservoir permeability during formation pressure drop, and the test result that use the condensate gas as the experimental fluid represent the effect of core skeleton damage and retrograde condensation on reservoir permeability. The results reveal that when the formation pressure drops to the dew point pressure, retrograde condensation damage is the main cause of permeability decline. And the effects of core skeleton damage will increase as the formation pressure drops and exceed the retrograde condensation damage when the net stress is greater 7 MPa. When the net stress reaches 20 MPa, the core skeleton damage accounts for more than 90% of the total damage. Furthermore, the gas well production was calculated considering stress sensitivity and retrograde condensation based on the experimental results, the result shows that gas well production decreases by 97.65% when retrograde condensation is considered. This study can provide a reference for quantitative evaluation of the retrograde condensation and stress sensitivity in the production process of condensate gas reservoir

    Research on the protection and reuse of industrial heritage from the perspective of public participation—a case study of northern mining area of Pingdingshan, China

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    With the decline of the big industrial period, many industrial cities in China are facing the problem of urban transformation. Post-industrial economic activities and social life often replace the demand for land and population growth, and the particular type of cultural heritage of industrial heritage is often abandoned and decayed. Recent domestic and foreign research has responded to this problem and sought to provide solutions for the protection and reuse of industrial heritage. Despite some progress, the advice and feelings of ordinary citizens are often rarely considered, or how local urban characteristics become the core of urban reconstruction. To solve this problem, the focus of this study is the case study of Pingdingshan City. Pingdingshan is an industrial city with coal as its core industry. Shortly, the problem of industrial heritage will be a severe problem facing the city. The study included research designs and methods for collecting data from field observations, questionnaires, interviews, and literature studies. In the process, researchers have critically considered the importance and implications of public participation in exploring the way in which they are protected and reused through the protection and reuse of industrial heritage. It is particularly worth mentioning that in the reconstruction of the protection and reuse of industrial heritage in Pingdingshan, government officials and enterprises lack sensitivity to local conditions and the views of residents. The study concluded that the protection and reuse of industrial heritage require public participation and that the public’s demands can guide and determine the way industrial heritage is protected and reused

    Position and orientation measurement technology for bolter miner body based on dual-screen visual target

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    Aiming at the problem that it is difficult to achieve the real-time and accurate measurement of the bolter miner’s position and orientation during the excavation process in coal mines, which leads to the difficulty in achieving directional excavation, a guidance method for bolter miner based on dual-screen visual target is proposed. Using two vertically installed light-sensitive imaging screens to form the dual-screen visual target surfaces and the indication laser emitted by the laser instrument presents light spots on the front and rear target surfaces. Combining with the visual measurement, high-precision raster calibration and other technology are applied to establish the mapping relationship of the spot centroid between 2D-3D coordinates, which is used to form the point cloud data of the coordinates. Based on the principle of grid indexing, coordinate transformation and Euler angle solving, combining with the biaxial inclinometer at the bottom of target to obtain the bolter miner body’s real-time position and orientation, the key points’ horizontal/vertical deviations relative to the roadway axis are calculated, which can provide data support for deviation correction during the excavation process. The off-target problem of the system is analyzed by constructing a mathematical model. Meanwhile, the effectiveness of the guidance method is verified by building an experimental platform. The experimental results indicate that this method can achieve a precision measurement of six-degrees-of-freedom spatial pose for the machine body. When the measurement distance is 9 m, the repeatability measurement precision of the yaw angle is better than 0.01º and the error of absolute measurement is less than 0.05º. Within the measurement range of 15−40 m, which uses the total station and mining laser to set the planning line, the measurement errors of key points’ horizontal/vertical deviations are less than 5 mm and 15 mm, respectively. The guiding system developed based on this method has also been successfully applied to the underground roadway excavation in coal mine, which fully meets the requirements of underground roadway excavation and the positioning of the machine body’s key points. The error characteristic of the guiding method is independent of the test distance. Also, all optical measurement functions involved in the method are realized inside the target, which can effectively shield the influence of the underground complex environment for the measurement function, and greatly improve the capacity of anti-dust interference in field application

    Transcriptome profiling reveals the role of ZBTB38 knock-down in human neuroblastoma

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    ZBTB38 belongs to the zinc finger protein family and contains the typical BTB domains. As a transcription factor, ZBTB38 is involved in cell regulation, proliferation and apoptosis, whereas, functional deficiency of ZBTB38 induces the human neuroblastoma (NB) cell death potentially. To have some insight into the role of ZBTB38 in NB development, high throughput RNA sequencing was performed using the human NB cell line SH-SY5Y with the deletion of ZBTB38. In the present study, 2,438 differentially expressed genes (DEGs) in ZBTB38−/− SH-SY5Y cells were obtained, 83.5% of which was down-regulated. Functional annotation of the DEGs in the Kyoto Encyclopedia of Genes and Genomes database revealed that most of the identified genes were enriched in the neurotrophin TRK receptor signaling pathway, including PI3K/Akt and MAPK signaling pathway. we also observed that ZBTB38 affects expression of CDK4/6, Cyclin E, MDM2, ATM, ATR, PTEN, Gadd45, and PIGs in the p53 signaling pathway. In addition, ZBTB38 knockdown significantly suppresses the expression of autophagy-related key genes including PIK3C2A and RB1CC1. The present meeting provides evidence to molecular mechanism of ZBTB38 modulating NB development and targeted anti-tumor therapies

    Characterization of Aniline Tetramer by MALDI TOF Mass Spectrometry upon Oxidative and Reductive Cycling.

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    By combining electrochemical experiments with mass spectrometric analysis, it is found that using short chain oligomers to improve the cycling stability of conducting polymers in supercapacitors is still problematic. Cycling tests via cyclic voltammetry over a potential window of 0 to 1.0 V or 0 to 1.2 V in a two-electrode device configuration resulted in solid-state electropolymerization and chain scission. Electropolymerization of the aniline tetramer to generate long chain oligomers is shown to be possible despite the suggested decrease in reactivity and increase in intermediate stability with longer oligomers. Because aniline oligomers are more stable towards reductive cycling when compared to oxidative cycling, future conducting polymer/oligomer-based pseudocapacitors should consider using an asymmetric electrode configuration

    Real-time Monitoring for the Next Core-Collapse Supernova in JUNO

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    Core-collapse supernova (CCSN) is one of the most energetic astrophysical events in the Universe. The early and prompt detection of neutrinos before (pre-SN) and during the SN burst is a unique opportunity to realize the multi-messenger observation of the CCSN events. In this work, we describe the monitoring concept and present the sensitivity of the system to the pre-SN and SN neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO), which is a 20 kton liquid scintillator detector under construction in South China. The real-time monitoring system is designed with both the prompt monitors on the electronic board and online monitors at the data acquisition stage, in order to ensure both the alert speed and alert coverage of progenitor stars. By assuming a false alert rate of 1 per year, this monitoring system can be sensitive to the pre-SN neutrinos up to the distance of about 1.6 (0.9) kpc and SN neutrinos up to about 370 (360) kpc for a progenitor mass of 30M⊙M_{\odot} for the case of normal (inverted) mass ordering. The pointing ability of the CCSN is evaluated by using the accumulated event anisotropy of the inverse beta decay interactions from pre-SN or SN neutrinos, which, along with the early alert, can play important roles for the followup multi-messenger observations of the next Galactic or nearby extragalactic CCSN.Comment: 24 pages, 9 figure

    Out-of-Plane Dynamic Response of Elliptic Curved Steel Beams Based on the Precise Integration Method

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    The dynamic response of curved steel beams has long been a research focus in curved bridges. The formula for the dynamic response under a moving load was derived according to the basic principles of the precise integration method. Combined with the necessary conditions of this method, the stiffness matrix of a variable-curvature beam was obtained using matrix inversion, and the mass matrix of the structure was obtained using the concentrated mass method. The dynamic response of the structure was obtained by applying moving loads and masses at different speeds to the curved beam. Finite element simulation and laboratory curved-beam models of the variable-curvature steel beam were established. By comparing the laboratory measurement results against the theoretical data obtained in this study, we propose that our theory has practical engineering significance. It can be used as a theoretical basis for the study of variable curvature steel beam structures and for guiding the construction of curved beams

    Heating Control Strategy Based on Dynamic Programming for Building Energy Saving and Emission Reduction

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    Finding the optimal balance between end-user’s comfort, lifestyle preferences and the cost of the heating, ventilation and air conditioning (HVAC) system, which requires intelligent decision making and control. This paper proposes a heating control method for HVAC based on dynamic programming. The method first selects the most suitable modeling approach for the controlled building among three machine learning modeling techniques by means of statistical performance metrics, after which the control of the HVAC system is described as a constrained optimization problem, and the action of the controller is given by solving the optimization problem through dynamic programming. In this paper, the variable ‘thermal energy storage in building’ is introduced to solve the problem that dynamic programming is difficult to obtain the historical state of the building due to the requirement of no aftereffect, while the room temperature and the remaining start hours of the Primary Air Unit are selected to describe the system state through theoretical analysis and trial and error. The results of the TRNSYS/Python co-simulation show that the proposed method can maintain better indoor thermal environment with less energy consumption compared to carefully reviewed expert rules. Compared with expert rule set ‘baseline-20 °C’, which keeps the room temperature at the minimum comfort level, the proposed control algorithm can save energy and reduce emissions by 35.1% with acceptable comfort violation
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