A distal enhancer controls transcription of FLOWERING LOCUS T in Arabidopsis

Control of flowering time is critical for reproductive success. In Arabidopsis thaliana, the gene FLOWERING LOCUS T (FT) encodes part of florigen, which moves from leaves to the shoot apex to induce the floral transition. Under inductive long days (LD), transcription activation is mainly mediated by CONSTANS (CO). The epigenetic repressor LHP1, which associates with H3K27me3, antagonizes CO activity in vascular tissues at FT. The 5.7 kb sequence upstream of the FT translation start codon contains sufficient regulatory elements to mediate spatial and temporal expression of FT. On this full length FT promoter, phylogenetic analysis identified three conserved blocks, each around 300 bp, called Block A, B and C. The aim of my study was to identify and characterize functional cis-elements within the conserved blocks and elucidate the molecular mechanisms of FT transcription regulation. My results indicate that Block C (5.2 to 5.6 kb upstream of the transcriptional start site) is necessary for FT expression in LD conditions, and that CCAAT boxes in Block C and close to Block A at the proximal promoter impair the efficiency of a full length FT promoter. Mutagenesis of either one of four conserved sub-blocks in Block C dramatically reduces promoter activity. Although Block C acts as distal enhancer, it requires specific sequences contained in Block A to convey phloem-specific expression of FT in leaves. Through Chromosome Conformation Capture (3C) assays, a weak long-distance physical interaction between Block C and A could be detected. The distance between Block C and A displays natural variation among different A. thaliana accessions. Shortening the distance between the blocks by deleting 3.5 kb intersecting region or directly connecting Block C and A, generated shorter versions of the FT promoter that mimic the full-length promoter function in response to LDs. How the repressive histone mark H3K27me3 and LHP1 contribute to FT regulation is still unclear. To study differential enrichment of H3K27me3 at the FT promoter, nuclei were isolated by INTACT (isolation of nuclei tagged in specific cell types) from the leaf phloem of plants grown in LD or SD conditions. Chromatin immunoprecipitation (ChIP) revealed that the abundance of H3K27me3 at Block C and A regions negatively correlated with FT expression levels in the phloem. Taken together, the distal enhancer Block C and Block A in the proximal promoter are accessible in leaf phloem cells and required and sufficient for FT expression in LD conditions

Female Images in The Great Gatsby

This paper tends to analyze female images in F. Scott Fitzgerald’s novel The Great Gatsby from a feminist perspective. It analyzes these three women characters--Daisy Fay, Myrtle Wilson, and Jordan Baker--in three aspects: characteristics of their images, the relationship between them and their intimate men, and their fight against patriarchy society. This paper tends to point out the similarities and differences of these three female images.

Research on vibration-isolating rate of vibration-isolating slot under buried pipe subjected to blasting seismic waves

The vibration-isolating rate of vibration isolating slot under buried pipe subjected to blasting seismic waves can been investigated by using the numerical method. For achieving a good vibration isolating effect, the depth of the vibration-isolating slot needs to be larger with the increase of the depth of the pore. The difference of the super-depth h leads to the difference in the trend of vibration isolating. The depth of the vibration-isolating slot is larger than the depth of the hole, which can improve the vibration-isolating rate. The different type of rock and soil medium is a significant effect on the vibration-isolating rate. To obtain ideal vibration-isolating effect, vibration-isolating slot depth compared with pipeline buried depth is greater than a certain value

Research on dynamic responses of incompletely water-filled cylindrical shell subjected to explosion impact

Numerical simulation on the deformations and damages of incompletely water-filled cylindrical shells subjected to explosion impacts were carried out. The Research shows that the degree of deformation and failure of the incompletely liquid-filled cylindrical shell is smaller than that of the empty cylindrical shell in the same condition. The dynamic response of the completely water-filled cylindrical shell subjected to 75gTNT explosion impact is the same with the one of partially water-filled cylindrical shell. The anti-explosion performance of the 95 % volume water-filled cylindrical shell subjected to 200gTNT explosion impact is better. The explosion direction greatly influenced the dynamic response of partially filled-water cylindrical shell. The dynamic response of a partially water-filled cylindrical shell is approximately the same as that of the fully water-filled cylindrical shell, when the explosion direction is on one side of the water. The results show that internal pressure of water will increase when subjecting to impact loading, the anti-blast ability of tube structure significantly enhanced

A temporal Convolutional Network for EMG compressed sensing reconstruction

Electromyography (EMG) plays a vital role in detecting medical abnormalities and analyzing the biomechanics of human or animal movements. However, long-term EMG signal monitoring will increase the bandwidth requirements and transmission system burden. Compressed sensing (CS) is attractive for resource-limited EMG signal monitoring. However, traditional CS reconstruction algorithms require prior knowledge of the signal, and the reconstruction process is inefficient. To solve this problem, this paper proposed a reconstruction algorithm based on deep learning, which combines the Temporal Convolutional Network (TCN) and the fully connected layer to learn the mapping relationship between the compressed measurement value and the original signal, and it has been verified in the Ninapro database. The results show that, for the same subject, compared with the traditional reconstruction algorithms orthogonal matching pursuit (OMP), basis pursuit (BP), and Modified Compressive Sampling Matching Pursuit (MCo), the reconstruction quality and efficiency of the proposed method is significantly improved under various compression ratios (CR)

Development and testing of a XYZ scanner for atomic force microscope

Atomic force microscopy (AFM) is a widely used tool in nano measurement and manipulation techniques. However, a traditional AFM system suffers from the limitation of slow scanning rate, due to the low dynamic performance of piezoelectric positioners. As an important part of AFM system, scanner will have a significant impact the result of the scanning imaging and operation. It is well know that high-speed operation of an AFM are increasingly required, and it is also a challenge for the researchers. In this paper, we proposed a parallel kinematic high-speed piezoelectric actuator (PZT) XYZ scanner. The design is aimed at achieving high resonance frequencies and low cross-coupling. The developed stage consists of a parallel kinematic XY stage and a Z stage. The Z stage is mounted on the central moving platform of the XY stage. To achieve the design objective, several parallel leaf flexure hinge mechanisms, arranging symmetrically around the central moving platform of the XY stage, are utilized to provide large stiffness and reduce cross-coupling. For the Z stage, a symmetrical leaf flexure parallelogram mechanism is adopted to achieve high resonance frequencies and decoupling. Then, finite element analysis (FEA) is utilized to validate the characteristics of the XYZ scanner. Finally, extensive experiments are conducted, demonstrating feasibility of the proposed scanner

Numerical simulation on fracture mechanics behavior of high-pressure gas pipeline

The numerical simulation could help to understand the fracture mechanics behavior of high-pressure gas pipeline. The calculation results show that the internal high pressure of gas provides a driving force for crack propagation and tube wall deformation when the pipeline cracks and expands. Therefore, the rapid crack propagation tends to occur when the steel pipe is driven by high-pressure gas. In the process of steel pipe crack extension, immense internal high-pressure gas spewed from rupture and expand rapidly, compressing the air to form a series of compression wave which propagate rapidly and superpose together to form a shock wave eventually. Because the explosive wave of the pipe rupture has a high directivity, the energy distribution of gas is not uniform during the releasing process. What’s more, in pipe blasting, the longer distance, the more the surface vibration velocity decreases. In the vicinity of explosion source, the decreasing trend of the peak vibration velocity is significant. The vertical vibration velocity at the same point is larger than the longitudinal and tangential vibration speed

Practical Quantum Simulation of Non-Hermitian Dynamics

Non-Hermitian quantum systems have recently attracted considerable attentions due to their exotic properties. Though many experimental realizations of non-Hermitian systems have been reported, the non-Hermiticity usually resorts to the hard-to-control environments. An alternative approach is to use quantum simulation with the closed system, whereas how to simulate general non-Hermitian Hamiltonian dynamics remains a great challenge. To tackle this problem, we propose a protocol by combining a dilation method with the variational quantum algorithm. The dilation method is used to transform a non-Hermitian Hamiltonian into a Hermitian one through an exquisite quantum circuit, while the variational quantum algorithm is for efficiently approximating the complex entangled gates in this circuit. As a demonstration, we apply our protocol to simulate the dynamics of an Ising chain with nonlocal non-Hermitian perturbations, which is an important model to study quantum phase transition at nonzero temperatures. The numerical simulation results are highly consistent with the theoretical predictions, revealing the effectiveness of our protocol. The presented protocol paves the way for practically simulating general non-Hermitian dynamics in the multi-qubit case.Comment: 9 pages, 5 figure

Exploring the relationship between distress rumination, resilience, depression, and self-injurious behaviors among Chinese college athletes infected with COVID-19: a cross-sectional study

ObjectivesDistress rumination is a cause of suicidality and self-injurious behavior (SSIB) among individuals. Although previous studies have shown that distress rumination, SSIB, resilience, and depression are significantly related, the interaction mechanism remains unclear. This study aimed to evaluate resilience and depression as mediators of the relationship between distress rumination and SSIB among Chinese college athletes infected with COVID-19.MethodsConvenience sampling was used to recruit participants from the National College Football Championship in Guangxi City, China from January to February 2023. Participants completed the Ruminative Responses Scale (RRS), a subscale of the Health-Risk Behavior Inventory (HBI), the Mental Toughness Index (MTI) and the Patient Health Questionnaire (PHQ-9). We used the PROCESS macro for SPSS to determine the mediating effect of resilience and depression between distress rumination and SSIB.ResultsA total of 350 Chinese college athletes participated in this study and completed the questionnaire survey. 289 (81.7% boys; Mage = 20.31 years, SD = 1.60) of them have been infected with COVID-19. 59.9% (n = 173) participants were from urban areas and 15.6% (n = 45) of participants have engaged in self-injurious behaviors or suicidal ideation. College athletes’ distress rumination was significantly negatively correlated with resilience (r = − 0.28, p < 0.01), and was significantly positively correlated with depression (r = 0.49, p < 0.01) and SSIB (r = − 0.18, p < 0.01). Resilience was significantly negatively correlated with depression (r = − 0.35, p < 0.01) and SSIB (r = − 0.30, p < 0.01). Finally, depression was significantly positively correlated with SSIB (r = − 0.38, p < 0.01). Resilience and depression played a mediating role of the total effects of distress rumination and SSIB, respectively. Meanwhile, the chain mediating effect of resilience and depression was also significant.ConclusionThis study found that distress rumination can directly predict SSIB, and indirectly predict SSIB through the mediating effect of resilience and depression, and the chain mediating effect of resilience-depression. Therefore, reducing the degree of distress rumination of college athletes infected by COVID-19 and improving their resilience, as well as reducing their depression may help prevent SSIB