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This paper proposes a dynamic event‐triggered fixed‐time control scheme for the phase synchronization of Kuramoto networks with switching topology and stochastic coupling noise. To deal with the problems of switching topology and stochastic coupling noise, a multilayered control structure with a specially designed noise reduction layer is developed. The effectiveness is proved based on stochastic differential theory. To save communication resources and reduce control frequency, a dynamic event‐triggered mechanism is proposed. By introducing a dynamic variable into the triggering condition, the triggered instants are further reduced compared to the traditional static event‐triggered method. The synchronizing criteria and parameter conditions are established with stochastic Lyapunov stability theory. The analysis of Zeno behavior is also given. Finally, numerical simulation experiments are conducted to demonstrate the effectiveness of the proposed dynamic event‐triggered control scheme. [ABSTRACT FROM AUTHOR]

The growing development of autonomous systems is driving the application of mobile robots in crowded environments. These scenarios often require robots to satisfy multiple conflicting objectives with different relative preferences, such as work efficiency, safety, and smoothness, which inherently cause robots' poor exploration in seeking policies optimizing several performance criteria. In this paper, we propose a multi-objective deep reinforcement learning framework for crowd-aware robot navigation problems to learn policies over multiple competing objectives whose relative importance preference is dynamic to the robot. First, a two-stream structure is introduced to separately extract the spatial and temporal features of pedestrian motion characteristics. Second, to learn navigation policies for each possible preference, a multi-objective deep reinforcement learning method is proposed to maximize a weighted-sum scalarization of different objective functions. We consider path planning and path tracking tasks, which focus on conflicting objectives of collision avoidance, target reaching, and path following. Experimental results demonstrate that our method can effectively navigate through crowds in simulated environments while satisfying different task requirements. [ABSTRACT FROM AUTHOR]

Introduction: Classic hemodialysis schedules present inadequate middle-molecular-weight toxin clearance due to limitations of membrane-based separation processes. Accumulation of uremic retention solutes may result in specific symptoms (e.g., pruritus) and may affect clinical outcome and patient's quality of life. Hemoperfusion (HP) is a blood purification modality based on adsorption that can overcome such limitations, and thus, it may be interesting to test the efficacy of at least one session per week of HP combined with hemodialysis. This is a randomized, open-label trial, controlled, multicenter clinical study to investigate the effect of long-term HP combined with hemodialysis on middle-molecular-weight toxins and uremic pruritus in maintenance hemodialysis (MHD) patients. Methods: 438 MHD patients from 37 HD centers in China with end-stage kidney disease (63.9% males, mean age 51 years) suffering from chronic intractable pruritus were enrolled in the study. Eligible patients were randomized into four groups: low-flux hemodialysis (LFHD), high-flux hemodialysis (HFHD), HP + LFHD, and HP + HFHD at a 1:1:1:1 ratio. Beta-2 microglobulin (β2M) and parathyroid hormone (PTH) were measured at baseline, 3–6, and 12 months. At the same time points, the pruritus score was evaluated. The primary outcome was the reduction of β2M and PTH, while the secondary outcome was the reduction of the pruritus score. Results: In the two groups HP + LFHD and HP + HFHD, there was a significant decrease of β2M and PTH levels after 12 months compared to the control groups. No significant differences were noted between HP + LFHD and HP + HFHD. Pruritus score reduction was 63% in the HP + LFHD group and 51% in the HP + HFHD group, respectively. Conclusion: The long-term HP + HD can reduce β2M and PTH levels and improve pruritus in MHD patients independently on the use of high- or low-flux dialyzers, showing that the results are linked to the effect of adsorption. [ABSTRACT FROM AUTHOR]

One-part geopolymers are a greener alternative to Portland cement and are more suitable in engineering applications compared with two-part geopolymers. The effects of mechanical activation on the properties and the mechanism of the pozzolanic reaction of fly ash (FA)/slag-based geopolymer paste prepared using the one-part method were studied. Simple mixing was used for the control group and the effect of mechanical activation on the macroscopic properties of geopolymers was studied using tests for compressive strength, fluidity and setting times. The effect of mechanical activation on the pozzolanic reaction of geopolymers was assessed using isothermal calorimetry, X-ray diffraction, Fourier transform infrared spectroscopy and thermogravimetric analysis. The results showed that the 28-day compressive strength of the geopolymer formed by mechanical activation was 26% higher than that of the geopolymer prepared using simple mixing. Workability and fluidity were also enhanced. The reactivity of the precursor was improved by mechanical activation, particularly for the FA. The mechanically activated FA experienced a pozzolanic reaction within 7 days, while the undisturbed FA produced pozzolanic activity after 14–28 days. In addition, mechanical activation lessened the carbonisation of the one-part FA/slag-based geopolymer The implications of these results in terms of the influence of mechanical activation on pozzolanic activity are discussed. [ABSTRACT FROM AUTHOR]

In this paper, we consider a pursuit-evasion game in which multiple pursuers attempt to capture one superior evader. A distributed cooperative pursuit strategy with communication is developed based on reinforcement learning. The centralized critic and distributed actor structure and the learning-based communication mechanism are adopted to solve the cooperative pursuit control problem. Instead of using broadcast to share information among the pursuers, we construct the ring topology network and the leader-follower line topology network for communication, which could significantly reduce the complexity and save the communication and computation resources. The training algorithms for these two network topologies are developed based on the deep deterministic policy gradient algorithm. Furthermore, the proposed approach is implemented in a simulation environment. The training and evaluation results demonstrate that the pursuit team could learn highly efficient cooperative control and communication policies. The pursuers can capture a superior evader driven by an intelligent escape policy with a high success rate. [ABSTRACT FROM AUTHOR]

In this paper, a deep reinforcement learning-based robust control strategy for quadrotor helicopters is proposed. The quadrotor is controlled by a learned neural network which directly maps the system states to control commands in an end-to-end style. The learning algorithm is developed based on the deterministic policy gradient algorithm. By introducing an integral compensator to the actor-critic structure, the tracking accuracy and robustness have been greatly enhanced. Moreover, a two-phase learning protocol which includes both offline and online learning phase is proposed for practical implementation. An offline policy is first learned based on a simplified quadrotor model. Then, the policy is online optimized in actual flight. The proposed approach is evaluated in the flight simulator. The results demonstrate that the offline learned policy is highly robust to model errors and external disturbances. It also shows that the online learning could significantly improve the control performance. [ABSTRACT FROM AUTHOR]

Aims: Non-diabetic renal diseases (NDRDs) are associated with better renal outcomes than diabetic nephropathy (DN). This study was conducted to determine the common clinical markers predicting NDRDs in type 2 diabetes patients.Methods: Patients with type 2 diabetes mellitus who underwent a renal biopsy were screened. Eligible patients were categorized into two groups: DN group and NDRD group. Patient's clinical characteristics and laboratory data were collected. Logistic regression analysis was performed to identify risk factors for NDRD development, and the diagnostic performance of these variables was evaluated.Results: The study included 248 patients, 96 (38.71%) in the DN group and 152 (61.29%) in the NDRD group. Patients in the NDRD group had a shorter duration of DM and higher hemoglobin, estimated glomerular filtration rate, and urine osmotic pressure values as well as a higher incidence of glomerular hematuria than patients in the DN group. In the NDRD patients, the most common pathological type was membranous nephropathy (55, 36.18%). Absence of retinopathy (OR, 44.696, 95% CI, 15.91-125.566), glomerular hematuria (OR, 9.587, 95% CI, 2.027-45.333), and DM history ⩽5years (OR, 4.636, 95% CI, 1.721-12.486) were significant and independent risk factors for the development of NDRD (P<0.01). Absence of retinopathy achieved the overall highest diagnostic efficiency with a sensitivity of 92.11% and specificity of 82.29%. Glomerular hematuria had the highest specificity (93.75%).Conclusion: Shorter duration of diabetes (⩽5years), absence of retinopathy, and presence of glomerular hematuria were independent indicators associated with NDRDs, indicating the need for renal biopsy. [ABSTRACT FROM AUTHOR]

This paper addresses the exponential consensus problem of single-integrator agents with saturated protocols on directed graphs. By employing an integral Lyapunov function, the exponential consensus problem of single-integrator agents is solved under the directed graph with strongly connected or a spanning tree. The main contribution is that under the directed graph, some conditions for exponential consensus with saturated protocols are first obtained. Finally, two examples are used to illustrate the effectiveness of the theoretical results. [ABSTRACT FROM AUTHOR]

Gamma detectors consisting of lanthanum bromide (LaBr 3) scintillator and silicon photomultiplier (SiPM) have extensive applications in various scientific fields. Accurate gamma energy measurement depends on accurate calibration of these detectors. While some studies have attempted detector self-calibration based on the natural background of LaBr 3 , these methods are limited to specific LaBr 3 crystals and lack generality. To address this limitation, this paper proposes a self-calibration method that solely utilizes the natural radioactivity of 138La. By solving for the maximum similarity between the test background from measurement and the standard spectrum obtained from the Geant4 simulation, the detector is effectively calibrated. Furthermore, the application of a series of energy spectrum processing algorithms simplifies the solution complexity of the maximum similarity problem. Experimental results from four different crystals at varying temperatures demonstrate calibration errors of less than 0.8% at 662 keV, highlighting the method's broad applicability and accuracy. Besides, the influence of the background measurement time and the natural environmental background on the self-calibration method are discussed in detail, further illustrating the value of the application. [ABSTRACT FROM AUTHOR]

The sparse reward problem has long been one of the most challenging topics in the application of reinforcement learning (RL), especially in complex multi-agent systems. In this paper, a hierarchical multi-agent RL architecture is developed to address the sparse reward problem of cooperative tasks in continuous domain. The proposed architecture is divided into two levels: the higher-level meta-agent implements state transitions on a larger time scale to alleviate the sparse reward problem, which receives global observation as spatial information and formulates sub-goals for the lower-level agents; the lower-level agent receives local observation and sub-goal and completes the cooperative tasks. In addition, to improve the stability of the higher-level policy, a channel is built to transmit the lower-level policy to the meta-agent as temporal information, and then a two-stream structure is adopted in the actor-critic networks of the meta-agent to process spatial and temporal information. Simulation experiments on different tasks demonstrate that the proposed algorithm effectively alleviates the sparse reward problem, so as to learn desired cooperative policies. [ABSTRACT FROM AUTHOR]

Reprograming of chromatin structures and changes in gene expression are critical for plant male gamete development, and epigenetic marks play an important role in these processes. Histone variant H3.3 is abundant in euchromatin and is largely associated with transcriptional activation. The precise function of H3.3 in gamete development remains unclear in plants. Here, we report that H3.3 is abundantly expressed in Arabidopsis anthers and its knockout mutant h3.3–1 is sterile due to male sterility. Transcriptome analysis of young inflorescence has identified 2348 genes downregulated in h3.3–1 mutant, among which 1087 target genes are directly bound by H3.3, especially at their 3ʹ ends. As a group, this set of H3.3 targets is enriched in the reproduction-associated processes including male gamete generation, pollen sperm cell differentiation and pollen tube growth. The function of H3.3 in male gamete development is dependent on the Anti-Silencing Factor 1A/1B (ASF1A/1B)-Histone regulator A (HIRA)-mediated pathway. Our results suggest that ASF1A/1B-HIRA-mediated H3.3 deposition at its direct targets for transcription activation forms the regulatory networks responsible for male gamete development. [ABSTRACT FROM AUTHOR]

This paper investigates the synchronization problem of the Kuramoto-oscillator network with non-identical oscillators. The fixed-time event-triggered synchronization control strategies are developed for phase agreement and frequency synchronization under both continuous and intermittent communication. With the developed fixed-time controller, the synchronization can be achieved within a pre-defined time for any initial phase of each oscillator. The event-triggered mechanism avoids continuous controller update and data transmission, which significantly saves the computation and communication resources. Furthermore, theoretical analysis shows that the fixed-time convergence can be guaranteed and the Zeno behavior is avoided by the proposed methods. The numerical simulations of each situation also verify the effectiveness of the proposed synchronization control strategies. [ABSTRACT FROM AUTHOR]

Middleboxes are widely used in modern networks for a variety of network functions in cybersecurity, performance enhancement, and monitoring. Middlebox policy enforcement is however complex and tedious with unreliable manual re-configuration of legacy routers. The existing solution on automated policy enforcement relies on software-defined networking and does not apply to the traditional non-SDN networks, which remain popular today in enterprise deployment and core networks. This paper proposes a new architecture based entirely on software-defined middleboxes (instead of using software-defined switches in the prior art) to enable dependable and automated policy enforcement in non-SDN networks whose routers forward packets based on traditional routing protocols that are not policy-sensitive. We present a hot-potato enforcement strategy, which is then enhanced with two optimizations for load-balanced policy enforcement among software-defined middleboxes. Next, we propose two additional optimizations that minimize total traffic and aggregate end-to-end delays subject to link capacity constraints. Further enhancements are made to relieve middlebox processing overhead, avoid packet fragmentation due to policy enforcement, recover from failures, and mitigate delay for time-sensitive applications. We evaluate the proposed architecture on a real-life campus network topology and two simulated topologies to demonstrate the superior performance of our load-balanced enforcement strategies. [ABSTRACT FROM AUTHOR]

[Display omitted] • Rice whole-genome duplication leads to alterations of phenotypes, gene transcriptions, 3D chromatin structures and DNA methylation. • Three-dimensional (3D) chromatin architectures including chromatin compartments and topologically associating domains (TADs) are uncorrelated with gene transcription upon rice genome duplication. • The first study to reveal the mechanism regarding the disconnection between 3D genome architecture and gene transcription. • Hypermethylated transposable elements (TEs) suppress the role of 3D chromatin structure in modulating gene transcription upon rice genome duplication. Polyploidy is a major force in plant evolution and the domestication of cultivated crops. The study aimed to explore the relationship and underlying mechanism between three-dimensional (3D) chromatin organization and gene transcription upon rice genome duplication. The 3D chromatin structures between diploid (2C) and autotetraploid (4C) rice were compared using high-throughput chromosome conformation capture (Hi-C) analysis. The study combined genetics, transcriptomics, whole-genome bisulfite sequencing (WGBS-seq) and 3D genomics approaches to uncover the mechanism for DNA methylation in modulating gene transcription through 3D chromatin architectures upon rice genome duplication. We found that 4C rice presents weakened intra-chromosomal interactions compared to its 2C progenitor in some chromosomes. In addition, we found that changes of 3D chromatin organizations including chromatin compartments, topologically associating domains (TADs), and loops, are uncorrelated with gene transcription. Moreover, DNA methylations in the regulatory sequences of genes in compartment A/B switched regions and TAD boundaries are unrelated to their expression. Importantly, although there was no significant difference in the methylation levels in transposable elements (TEs) in differentially expressed gene (DEG) and non-DEG promoters between 2C and 4C rice, we found that the hypermethylated TEs across genes in compartment A/B switched regions and TAD boundaries may suppress the expression of these genes. The study proposed that the rice genome doubling might modulate TE methylation to buffer the effects of chromatin architecture on gene transcription in compartment A/B switched regions and TAD boundaries, resulting in the disconnection between 3D chromatin structure alteration and gene transcription upon rice genome duplication. [ABSTRACT FROM AUTHOR]

Background: Mesenchymal stem cells (MSCs) have emerged as a promising cell-based therapy for acute kidney injury (AKI). However, the optimal route of MSC transplantation remains controversial, and there have been no comparisons of the therapeutic benefits of MSC administration through different delivery routes. Methods: In this study, we encapsulated MSCs into a collagen matrix to help achieve local MSC retention in the kidney and assessed the survival of MSCs in vitro and in vivo. After transplanting collagen matrix-encapsulated-MSCs (Col-MSCs) under the renal capsule or into the parenchyma using the same cell dose and suspension volume in an ischemia/reperfusion injury model, we evaluated the treatment efficacy of two local transplantation routes at different stages of AKI. Results: We found that Col-MSCs could be retained in the kidney for at least 14 days. Both local MSC therapies could reduce tubular injury, promote the proliferation of renal tubular epithelial cells on Day 3 and alleviate renal fibrosis on Day 14 and 28. MSC transplantation via the subcapsular route exerts better therapeutic effects for renal functional and structural recovery after AKI than MSC administration via the parenchymal route. Conclusions: Subcapsular MSC transplantation may be an ideal route of MSC delivery for AKI treatment, and collagen I can provide a superior microenvironment for cell–cell and cell–matrix interactions to stabilize the retention rate of MSCs in the kidney. [ABSTRACT FROM AUTHOR]

Background/Aims: Reports have suggested that the traditional Chinese medicine Smilacis Glabrae Rhizoma attenuates hyperuricemia, but its mechanism is unclear. Our previous study demonstrated that uric acid could induce the generation of reactive oxygen species(ROS), which subsequently cause endothelial dysfunction. Therefore, we focused on the oxidative stress process. In this study, we would use LC-MS and bioinformatic analysis to investigate the underlying mechanism. Methods: We utilized LC-MS to reveal the differential protein expression in the kidneys of rats in the hyperuricemia group and the Smilacis Glabrae Rhizoma treatment group and then subjected the differentially expressed proteins to bioinformatic analysis. We also determined the serum ROS level of the two groups. According the above results, we built our hypothesis and performed in vitro experiments to validate this hypothesis. Results: We found that catalase was upregulated in the group treated with Smilacis Glabrae Rhizoma, and the level of reactive oxygen species was higher in the hyperuricemia group. Thus, we speculated that Smilacis Glabrae Rhizoma could alleviate oxidative stress by upregulating catalase. In vitro experiments, we found that high concentrations of uric acid reduced catalase expression in endothelial cells, which was alleviated by Smilacis Glabrae Rhizoma and resulted in a reduction of reactive oxygen species. Knockdown of catalase led to an increase in reactive oxygen species. Conclusion: We demonstrated that Smilacis Glabrae Rhizoma could alleviate the oxidative stress caused by hyperuricemia by upregulating catalase expression. This finding could represent a new application for Smilacis Glabrae Rhizoma in the treatment of hyperuricemia. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]