A Policy Optimization Method Towards Optimal-time Stability

In current model-free reinforcement learning (RL) algorithms, stability criteria based on sampling methods are commonly utilized to guide policy optimization. However, these criteria only guarantee the infinite-time convergence of the system's state to an equilibrium point, which leads to sub-optimality of the policy. In this paper, we propose a policy optimization technique incorporating sampling-based Lyapunov stability. Our approach enables the system's state to reach an equilibrium point within an optimal time and maintain stability thereafter, referred to as "optimal-time stability". To achieve this, we integrate the optimization method into the Actor-Critic framework, resulting in the development of the Adaptive Lyapunov-based Actor-Critic (ALAC) algorithm. Through evaluations conducted on ten robotic tasks, our approach outperforms previous studies significantly, effectively guiding the system to generate stable patterns.Comment: 27 pages, 11 figues. 7th Annual Conference on Robot Learning. 202

Loss of FKBP5 Affects Neuron Synaptic Plasticity: An Electrophysiology Insight

FKBP5 (FKBP51) is a glucocorticoid receptor (GR) binding protein, which acts as a co-chaperone of heat shock protein 90 (HSP90) and negatively regulates GR. Its association with mental disorders has been identified, but its function in disease development is largely unknown. Long-term potentiation (LTP) is a functional measurement of neuronal connection and communication, and is considered one of the major cellular mechanisms that underlies learning and memory, and is disrupted in many mental diseases. In this study, a reduction in LTP in Fkbp5 knockout (KO) mice was observed when compared to WT mice, which correlated with changes to the glutamatergic and GABAergic signaling pathways. The frequency of mEPSCs was decreased in KO hippocampus, indicating a decrease in excitatory synaptic activity. While no differences were found in levels of glutamate between KO and WT, a reduction was observed in the expression of excitatory glutamate receptors (NMDAR1, NMDAR2B and AMPAR), which initiate and maintain LTP. The expression of the inhibitory neurotransmitter GABA was found to be enhanced in Fkbp5 KO hippocampus. Further investigation suggested that increased expression of GAD65, but not GAD67, accounted for this increase. Additionally, a functional GABAergic alteration was observed in the form of increased mIPSC frequency in the KO hippocampus, indicating an increase in presynaptic GABA release. Our findings uncover a novel role for Fkbp5 in neuronal synaptic plasticity and highlight the value of Fkbp5 KO as a model for studying its role in neurological function and disease development

Automatic interval management for aircraft based on dynamic fuzzy speed control considering uncertainty

A novel real-time autonomous Interval Management System (IMS) is proposed to automate interval management, which considers the effect of wind uncertainty using the Dynamic Fuzzy Velocity Decision (DFVD) algorithm. The membership function can be generated dynamically based on the True Air Speed (TAS) limitation changes in real time and the interval criterion of the adjacent aircraft, and combined with human cognition to formulate fuzzy rules for speed adjusting decision-making. Three groups of experiments were conducted during the en-route descent stage to validate the proposed IMS and DFVD performances, and to analyze the impact factors of the algorithm. The verification experimental results show that compared with actual flight status data under controllers’ command, the IMS reduces the descent time by approaching 30% with favorable wind uncertainty suppression performance. Sensitivity analysis shows that the ability improvement of DFVD is mainly affected by the boundary value of the membership function. Additionally, the dynamic generation of the velocity membership function has greater advantages than the static method in terms of safety and stability. Through the analysis of influencing factors, we found that the interval criterion and aircraft category have no significant effect on the capability of IMS. In a higher initial altitude scenario, the initial interval should be appropriately increased to enhance safety and efficiency during the descent process. This prototype system could evolve into a real-time Flight-deck Interval Management (FIM) tool in the future

A Multiphase Strategy for Realizing Green Cathodoluminescence in 12CaO·7Al2O3–CaCeAl3O7:Ce3+,Tb3+ Conductive Phosphor

A multiphase strategy is proposed and successfully applied to make the insulating green phosphor CaCeAl3O7:Tb3+ conductive in the form of 12CaO·7Al2O3–CaCeAl3O7:Ce3+,Tb3+. The phosphor shows bright green-light emission with a short lifetime (2.51 ms) under low-voltage electron beam excitation (3 kV). The green photo- and cathodoluminescence from 5D4–7FJ (J = 6, 5, 4, 3) transitions of Tb3+ are significantly enhanced in comparison with pure C12A7:Tb3+. It was confirmed that this enhancement is the consequence of the joint effects of energy transfer from Ce3+ to Tb3+ and broadening of the absorption spectrum of Ce3+ due to the existence of multiple phases. In particular, under 800 V electron beam excitation, cathodoluminescence is improved by the modified electrical conductivity of the phosphor. When compared to the commercial Zn2SiO4:Mn2+ with a long luminescence lifetime of 11.9 ms, this conductive green phosphor has greater advantage for fast displays

The FKBP5 Gene Affects Alcohol Drinking in Knockout Mice and Is Implicated in Alcohol Drinking in Humans

FKBP5 encodes FK506-binding protein 5, a glucocorticoid receptor (GR)-binding protein implicated in various psychiatric disorders and alcohol withdrawal severity. The purpose of this study is to characterize alcohol preference and related phenotypes in Fkbp5 knockout (KO) mice and to examine the role of FKBP5 in human alcohol consumption. The following experiments were performed to characterize Fkpb5 KO mice. (1) Fkbp5 KO and wild-type (WT) EtOH consumption was tested using a two-bottle choice paradigm; (2) The EtOH elimination rate was measured after intraperitoneal (IP) injection of 2.0 g/kg EtOH; (3) Blood alcohol concentration (BAC) was measured after 3 h limited access of alcohol; (4) Brain region expression of Fkbp5 was identified using LacZ staining; (5) Baseline corticosterone (CORT) was assessed. Additionally, two SNPs, rs1360780 (C/T) and rs3800373 (T/G), were selected to study the association of FKBP5 with alcohol consumption in humans. Participants were college students (n = 1162) from 21–26 years of age with Chinese, Korean or Caucasian ethnicity. The results, compared to WT mice, for KO mice exhibited an increase in alcohol consumption that was not due to differences in taste sensitivity or alcohol metabolism. Higher BAC was found in KO mice after 3 h of EtOH access. Fkbp5 was highly expressed in brain regions involved in the regulation of the stress response, such as the hippocampus, amygdala, dorsal raphe and locus coeruleus. Both genotypes exhibited similar basal levels of plasma corticosterone (CORT). Finally, single nucleotide polymorphisms (SNPs) in FKBP5 were found to be associated with alcohol drinking in humans. These results suggest that the association between FKBP5 and alcohol consumption is conserved in both mice and humans

LncRNA PGM5-AS1 inhibits non-small cell lung cancer progression by targeting miRNA-423-5p/SLIT2 axis

Abstract Non-small cell lung cancer (NSCLC) is a common and aggressive primary malignancy worldwide. Dysregulation of long non-coding RNAs (lncRNAs) has been shown to play an essential regulatory role in multiple cancers. However, the role of PGM5-AS1 in NSCLC remains unclear. Here, we found that PGM5-AS1 was down-regulated in NSCLC tissues and cells. Furthermore, reduced PGM5-AS1 expression levels were associated with larger tumor size, positive lymph node metastasis, advanced TNM stage and worse prognosis. We found that overexpression of PGM5-AS1 inhibited cell proliferation and metastasis, and induced apoptosis and G0/G1 cell cycle arrest in NSCLC cell lines. Using dual luciferase gene reporter and RNA immunoprecipitation assays, we confirmed that miR-423-5p interacted with PGM5-AS1, and that their expression levels were negatively correlated in NSCLC tissues. miR-423-5p was also found to reverse PGM5-AS1-induced malignant biological behavior. Moreover, we identified slit guidance ligand 2 (SLIT2) as a target gene of miR-423-5p. Using a dual luciferase gene reporter assay, we confirmed the regulatory relationship between SLIT2 and miR-423-5p and demonstrated that their expression levels were negatively correlated. Our rescue experiments showed that SLIT2 knockdown reversed miR-423-5p-mediated effects. Overall, this study identifies PGM5-AS1 as a potential prognostic biomarker for NSCLC and shows that PGM5-AS1 suppresses NSCLC development by regulating the miR-423-5p/SLIT2 axis

Non‐Diazo C−H Insertion Approach to Cyclobutanones through Oxidative Gold Catalysis

Cyclobutanones are synthetically versatile compounds that often require extensive effort to access. Herein, we report a facile synthesis of cyclobutanones based on the C(sp3 )-H insertion chemistry of oxidatively generated gold carbenes. Various cyclobutanones were obtained in synthetically useful yields from substrates with minimal structural prefunctionalization. This discovery reveals new synthetic utilities of gold-catalyzed oxidative transformations of alkynones

Super resolution reconstruction of digital core image based on transfer learning

The resolution of a digital core image obtained by CT scanning is inversely proportional to the core size. The sample size of the core plunger is large; therefore, the core image has low-resolution and loses microstructure information, which is difficult to meet the needs of follow-up research on core pores, fractures, rock skeleton and so on. By selecting a suitable position on the plunger sample, drilling one or more small-size subsamples for scanning to obtain the high-resolution image, the plunger core subsample image has both high-resolution and low-resolution. Due to the limited core image data of small-size plug samples, it cannot meet the demand for the number of training samples in super-resolution reconstruction based on depth learning. To solve the above problems, this paper first uses the low-resolution plunger sample image and its down sampled image to form the training data set, and then uses the SRResNet algorithm for model pretraining. Secondly, all the feature extraction layer parameters in the pre-trained model are frozen, and the model is retrained with the measured high-resolution plunger sample images and the corresponding low-resolution image in the plunger samples. The experimental results show that after 100 epochs of training, the loss function value of the SRResNet algorithm based on transfer learning is close to 0, and the PSNR value reaches 34. And the algorithm converges very fast, after about 30 epochs of training, the PSNR value is close to 34. Based on the transfer learning and SRResNet algorithm, the details such as small pores and textures that cannot be clearly displayed in the original image can be reconstructed, which can effectively realize the super-resolution reconstruction of digital core images

Influences of reservoir operation on terrestrial water storage changes detected by GRACE in the Yellow River basin

The implementation of water–sediment regulation scheme (WSRS) in the Yellow River can induce instantaneous water redistribution over regions through frequent reservoir operation. In this study, we attempt to detect the signal of changes in terrestrial water storage (TWS) induced by reservoir operation during WSRS based on GRACE data. Meanwhile, a modified index is proposed to further assess the contributions of human activities and climatic variability to annual changes in TWS. The results indicated that the impounding or releasing events in the XLD reservoir and the LYX reservoir during WSRS can be well detected by monthly GRACE CSR solutions with the DDK3 filter. In addition, there exists a significant correlation between annual changes in TWS and reservoir water storage changes within both the catchment area above the LYX reservoir (rs = 0.88, p < 0.01) and the catchment area above the XLD reservoir (rs = 0.86, p < 0.01). The modified index proposed in this study, which is an attribution index based on a variation analysis, showed that reservoir operation contributes significantly to changes in TWS especially for heavily reservoir-regulated regions

3D printed b-TCP scaffold with sphingosine 1-phosphate coating promotes osteogenesis and inhibits inflammation

Traditional treatments for bone repair with allografts and autografts are limited by the source of bone substitutes. Bone tissue engineering via a cell-based bone tissue scaffold is a new strategy for treatment against large bone defects with many advantages, such as the accessibility of biomaterials, good biocompatibility and osteoconductivity; however, the inflammatory immune response is still an issue that impacts osteogenesis. Sphingosine 1-phosphate (S1P) is a cell-derived sphingolipid that can mediate cell proliferation, immunoregulation and bone regeneration. We hypothesised that coating S1P on a β-Tricalcium phosphate (β-TCP) scaffold could regulate the immune response and increase osteogenesis. We tested the immunoregulation capability on macrophages and the osteogenic capability on rat bone marrow stromal cells of the coated scaffolds, which showed good biocompatibility. Additionally, the coated scaffolds exhibited dose-dependent inhibition of inflammatory-related gene expression. A high concentration of S1P (0.5 μM) upregulated osteogenic-related gene expression of OPN, OCN and RUNX2, which also significantly increased the alkaline phosphatase activity, as compared with the control group. In conclusion, S1P coated β-TCP scaffold could inhibit inflammation and promote bone regeneration