Active random force promotes diffusion in bacterial cytoplasm

Experiments have found that diffusion in metabolically active cells is much faster than in dormant cells, especially for large particles. However, the mechanism of this size-dependent diffusion enhancement in living cells is still unclear. In this work, we approximate the net effect of metabolic processes as a white-noise active force and simulate a model system of bacterial cytoplasm with a highly polydisperse particle size distribution. We find that diffusion enhancement in active cells relative to dormant cells can be more substantial for large particles. Our simulations agree quantitatively with the experimental data of Escherichia coli, suggesting an autocorrelation function of the active force proportional to the cube of particle radius. We demonstrate that such a white-noise active force is equivalent to an active force of about 0.57 pN with random orientation. Our work unveils an emergent simplicity of random processes inside living cells.Comment: 20 pages, 18 figure

Contagion in a Financial System

Financial contagion is often observed in recent financial crisis, which illustrates a critical need for new and fundamental understanding of its dynamics. So in this paper we mainly focus on modeling and analysing the financial contagion in a system where a large number of financial institutions are randomly connected by the direct balance sheets linkages own to the lending or borrowing relationships. We propose a simple contagion algorithm to study the effect of several determinants, such as the topology of financial network, exposure ratio, leverage ratio, and the liquidation ratio. One of our finding is that the financial contagion is weaker as the growth of connectivity of network, so a financial system with a higher connectivity is more stability or robustness; we also find that the exposure ratio increases the risk of financial contagion, but both the leverage ratio and liquidation ratio has a negative relationship on financial contagion

The Improvement and application of elevation measurement method with total station

In this paper, by analyzing the limitations of the traditional trigonometric elevation method, and on the basis of establishing a mathematical model of trigonometric elevation, a convenient and fast trigonometric elevation method without instrument height and prism height is improved, and the operation steps of the method are introduced in detail. The accuracy analysis was evaluated and the method was applied to actual engineering. The results show that under the premise of ensuring the measurement accuracy, this method not only reduces the range of measurement error sources, but also improves the measurement efficiency

Preliminary Discussion on Monitoring of Steel Support Axis Force in Metro Engineering

Axial force monitoring of steel support is one of the important factors for foundation pit safety monitoring. In the monitoring of steel support, there are many problems, such as unreasonable installation of axonometer, irregular monitoring behavior of axonometer, incomplete analysis of axial force and imperfect early warning system. Collecting many engineering cases, and in-depth analysis and research on the problems and irregular behavior of steel support axial force monitoring in every link. The influencing factors and control measures of steel support axial force are discussed in detail, and some useful conclusions are obtained. It has been applied in the actual monitoring work and achieved good results. It is of great significance to guide subway safety construction and promote the development of axle force monitoring industry

Diffusion enhancement in bacterial cytoplasm through an active random force

Experiments have found that diffusion in metabolically active cells is much faster than in dormant cells, especially for large particles. However, the mechanism of this size-dependent diffusion enhancement in living cells is still unclear. In this Letter, we approximate the net effect of metabolic processes as a white-noise active force and simulate a model system of bacterial cytoplasm with a highly polydisperse particle size distribution. We find that diffusion enhancement in active cells relative to dormant cells can be more substantial for large particles. Our simulations agree quantitatively with the experimental data of Escherichia coli, suggesting an autocorrelation function of the active force proportional to the cube of the particle radius. We demonstrate that such a white-noise active force is equivalent to an active force of about 0.57 pN with random orientation. Our work unveils an emergent simplicity of random processes inside living cells

Genome-Wide Identification of TCP Family Transcription Factors in Medicago truncatula Reveals Significant Roles of miR319-Targeted TCPs in Nodule Development

TCP proteins, the plant-specific transcription factors, are involved in the regulation of multiple aspects of plant development among different species, such as leaf development, branching, and flower symmetry. However, thus far, the roles of TCPs in legume, especially in nodulation are still not clear. In this study, a genome-wide analysis of TCP genes was carried out to discover their evolution and function in Medicago truncatula. In total, 21 MtTCPs were identified and classified into class I and class II, and the class II MtTCPs were further divided into two subclasses, CIN and CYC/TB1. The expression profiles of MtTCPs are dramatically different. The universal expression of class I MtTCPs was detected in all organs. However, the MtTCPs in CIN subclass were highly expressed in leaf and most of the members in CYC/TB1 subclass were highly expressed in flower. Such organ-specific expression patterns of MtTCPs suggest their different roles in plant development. In addition, most MtTCPs were down-regulated during the nodule development, except for the putative MtmiR319 targets, MtTCP3, MtTCP4, and MtTCP10A. Overexpression of MtmiR319A significantly reduced the expression level of MtTCP3/4/10A/10B and resulted in the decreased nodule number, indicating the important roles of MtmiR319-targeted MtTCPs in nodulation. Taken together, this study systematically analyzes the MtTCP gene family at a genome-wide level and their possible functions in nodulation, which lay the basis for further explorations of MtmiR319/MtTCPs module in association with nodule development in M. truncatula

The Effect of Inflammation on the Formation of Thyroid Nodules

Background. Some studies have demonstrated that inflammation is highly associated with the prevalence of thyroid nodules (TNs). However, more confounders, such as metabolic diseases, should be adjusted. Methods. A clinical study collecting 2722 subjects was conducted to confirm the association between inflammation and TNs. The underlying mechanism was investigated in combination with bioinformatics analysis. Results. In the clinical study, propensity score matching was used to match metabolic parameters and other confounders, and it is observed that subjects with high inflammation had a higher prevalence of TNs and thyroid-stimulating hormone (TSH) than those with low inflammation. After further matching TNs, it is found that inflammation was positively associated with TSH, which was also demonstrated in a population without TNs. In bioinformatics study, inflammation did not promote TNs formation directly. Instead, it inhibited the synthesis of thyroid hormone, which might be the cause of the elevated TSH coexisting with inflammation. Conclusion. Inflammation promotes the development of TNs disease, probably due to its indirect effect through inhibiting the synthesis of thyroid hormone, which results in the elevation of TSH

Weakly Supervised 3D Multi-Person Pose Estimation for Large-Scale Scenes Based on Monocular Camera and Single LiDAR

Depth estimation is usually ill-posed and ambiguous for monocular camera-based 3D multi-person pose estimation. Since LiDAR can capture accurate depth information in long-range scenes, it can benefit both the global localization of individuals and the 3D pose estimation by providing rich geometry features. Motivated by this, we propose a monocular camera and single LiDAR-based method for 3D multi-person pose estimation in large-scale scenes, which is easy to deploy and insensitive to light. Specifically, we design an effective fusion strategy to take advantage of multi-modal input data, including images and point cloud, and make full use of temporal information to guide the network to learn natural and coherent human motions. Without relying on any 3D pose annotations, our method exploits the inherent geometry constraints of point cloud for self-supervision and utilizes 2D keypoints on images for weak supervision. Extensive experiments on public datasets and our newly collected dataset demonstrate the superiority and generalization capability of our proposed method. Project homepage is at \url{https://github.com/4DVLab/FusionPose.git}

Hybrid semantic conflict prevention in real-time collaborative programming

Real-time collaborative programming allows a group of programmers to edit the same source code at the same time. To support semantic conflict prevention in real-time collaboration, a dependency-based automatic locking (DAL) approach was proposed in prior work. The DAL mechanism automatically detects programming elements with dependency relationships, and prohibits concurrent editing on the inter-dependent source code regions by locking. However, the prior DAL scheme is too restrictive, which leads to an unnecessarily large locking scope and seriously impacts the concurrent work. To address this issue, we propose a novel hybrid semantic conflict prevention (HSCP) scheme, to achieve a better balance between conflict prevention and concurrent work. The scheme enforces locking on the working and strongly-depended regions, while applies awareness highlight on weakly-depended regions. The depth of locking scope can be customized by each programmer in a fine-grained manner. A three-level awareness mechanism has been designed for programmers to intuitively distinguish working, strongly-depended and weakly-depended regions. In supporting the scheme, we have devised techniques and solutions, and implemented a prototype that supports programmers to enjoy hybrid semantic conflict prevention in real-time collaborative programming over Eclipse and IntelliJ IDEA platforms. Experimental evaluations have confirmed the satisfactory performance of the scheme in complex real-world scenarios