Modeling and active disturbance rejection control for sequential airdrop operations

With the assumption t at the motion acceleration of the cargo is unknown, the dynamic model that accords with the engineering practice of sequential cargo airdrop operations is derived by using the separation body method, which can describe the impact of the sequential moving cargos on the flight safety and airdrop-mission capacity. On this basis, a novel flight control method is designed based on the active disturbance rejection control (ADRC) theory. the system is decoupled and linearized through the nonlinear state error feedback; the total unknown disturbances, including unmolded dynamics and uncertainty, are estimated and compensated real-timely by the extended state observer. Moreover, with the consideration of the time-delay system, the ADRC is improved to enhance the accuracy and rapidity of the control system. Simulations are carried out under the condition that one transport aircraft performs sequential airdrop operations. The results verify that the desirable performance and robustness have been achieved and the proposed control method is quite competent for the sequential airdrop operations

Research on solitons interactions' in one-dimensional indium chains on Si(111) surfaces

Solitons have garnered significant attention across various fields, yet a contentious debate persists regarding the precise structure of solitons on indium chains. Currently, multiple forms of solitons in one-dimensional atomic chains have been reported. STM provides an effective means to study the precise atomic structure of solitons, particularly their dynamics and interactions. However, limited research has been conducted on soliton interactions and soliton-chain interactions, despite their profound impact on relative soliton motions and the overall physical properties of the system. In this work, we characterized the structures of the soliton dimer and trimer, observed the displacements induced by the soliton entity and statisticized the dynamic behaviors of soliton dimers over time evolution or temperature. To reveal the soliton mechanism, we further utilized STM to investigate the CDWs between two solitons when two monomers were encountered. Additionally, we achieved the manipulation of the monomer on the indium chain by the STM tip. Our work serves as an important approach to elucidate interactions in correlated electronic systems and advance the development of potential topological soliton computers

Tryptophan-kynurenine pathway as a novel link between gut microbiota and schizophrenia: A review

Gut microbiota and its metabolite tryptophan play an important role in regulating neurotransmission, immune homeostasis and oxidative stress which are critical for brain development. The kynurenine pathway is the main route of tryptophan catabolism. Kynurenine metabolites regulate many biological processes including host-microbiome communication, immunity and oxidative stress, as well as neuronal excitability. The accumulation of metabolites produced by kynurenine pathway in brain results in the activation of the immune system (increase in the levels of inflammatory factors) and oxidative stress (production of reactive oxygen species, ROS), which are associated with mental disorders, for example schizophrenia. Thus, it was hypothesized that perturbations in kynurenine pathway could cause activation of immunity, and that oxidative stress may be involved in the etiology of schizophrenia. The present work is a review of the latest studies on the possible role of kynurenine pathway in schizophrenia, and mechanism(s) involved

Neural networks-based robust adaptive flight path tracking control of large transport

For the ultralow altitude airdrop decline stage, many factors such as  actuator nonlinearity, the uncertain atmospheric disturbances, and model  unknown nonlinearity affect the precision of trajectory tracking. A robust  adaptive neural network dynamic surface control method is proposed. The  neural network is used to approximate unknown nonlinear continuous  functions of the model, and a nonlinear robust term is introduced to  eliminate the actuator’s nonlinear modeling error and external disturbances. From Lyapunov stability theorem, it is rigorously proved that all the signals in the closed-loop system are bounded. Simulation results confirm the perfect tracking performance and strong robustness of the proposed method

Atomic structure, energetics, and dynamics of topological solitons in Indium chains on Si(111) surfaces

Based on scanning tunneling microscopy and first-principles theoretical studies, we characterize the precise atomic structure of a topological soliton in In chains grown on Si(111) surfaces. Variable-temperature measurements of the soliton population allow us to determine the soliton formation energy to be ~60 meV, smaller than one half of the band gap of ~200 meV. Once created, these solitons have very low mobility, even though the activation energy is only about 20 meV; the sluggish nature is attributed to the exceptionally low attempt frequency for soliton migration. We further demonstrate local electric field-enhanced soliton dynamics.Comment: 5 pages, 3 figure

Mixed-attitude three-way decision model for aerial targets: Threat assessment based on IF-VIKOR-GRA method

Assessing potential threats typically necessitates the use of a robust mathematical model, a comprehensive evaluation method and universal decision rules. A novel approach is utilized in this study to optimize existing threat assessment (TA) algorithms and three-way decision models (3WDMs) are leveraged that incorporate decision-theoretic rough sets (DTRSs) within dynamic intuitionistic fuzzy (IF) environments to create a mixed-attitude 3WDM based on the IF-VIKOR-GRA method in the context of aviation warfare. The primary objectives of this study include determining conditional probabilities for IF three-way decisions (3WDs) and establishing mixed-attitude decision thresholds. Both the target attribute and loss function are expressed in the form of intuitionistic fuzzy numbers (IFNs). To calculate these conditional probabilities, an IF technique is used to combine the multi-attribute decision-making (MADM) method VIKOR and the grey relational analysis (GRA) method, while also taking into account the risk-related preferences of decision-makers (DMs). Optimistic and pessimistic 3WDMs are developed from the perspectives of membership degree and non-membership degree, then subsequently integrated into the comprehensive mixed-attitude 3WDM. The feasibility and effectiveness of this methodology are demonstrated through a numerical example and by comparison to other existing approaches

The Role of Butyric Acid in Treatment Response in Drug-Naive First Episode Schizophrenia

Background: Butyric acid, a major short-chain fatty acid (SCFA), has an important role in the microbiota-gut-brain axis and brain function. This study investigated the role of butyric acid in treatment response in drug-naive first episode schizophrenia. Methods: The study recruited 56 Chinese Han schizophrenia inpatients with normal body weight and 35 healthy controls. Serum levels of butyric acid were measured using Gas Chromatography-Mass Spectrometer (GC-MS) analysis at baseline (for all participants) and 24 weeks after risperidone treatment (for patients). Clinical symptoms were measured using the Positive and Negative Syndrome Scale (PANSS) for patients at both time points. Results: At baseline, there was no significant difference in serum levels of butyric acid between patients and healthy controls (p = 0.206). However, there was a significant increase in serum levels of butyric acid in schizophrenia patients after 24-week risperidone treatment (p = 0.030). The PANSS total and subscale scores were decreased significantly after 24-week risperidone treatment (p\u27s \u3c 0.001). There were positive associations between baseline serum levels of butyric acid and the reduction ratio of the PANSS total and subscale scores after controlling for age, sex, education, and duration of illness (p\u27s \u3c 0.05). Further, there was a positive association between the increase in serum levels of butyric acid and the reduction of the PANSS positive symptoms subscale scores (r = 0.38, p = 0.019) after controlling for potential confounding factors. Conclusions: Increased serum levels of butyric acid might be associated with a favorable treatment response in drug-naive, first episode schizophrenia. The clinical implications of our findings were discussed

Active disturbance rejection control for heavy cargo airdrop operations

In view of the strong nonlinear and coupling characteristics of the airdrop operations, a novel control method is proposed based on the active disturbance rejection control (ADRC) for decoupling control strategy of the pitch angle and airspeed. The unknown disturbances, including aerodynamic uncertainty and nonlinear coupling effect between the aircraft and cargo dynamics, are estimated and compensated with the extended state observer (ESO). Meanwhile, the nonlinear law state error feedback (NLSEF) is adopted to restrain the compensation residual. Simulation and flight quality evaluation shows the satisfactory capacity and strong robustness of the proposed control method in guaranteeing the airdrop task and flight safety

The Pichia pastoris transmembrane protein GT1 is a glycerol transporter and relieves the repression of glycerol on AOX1 expression

Promoter of alcohol oxidase I (PAOX1) is the most efficient promoter involved in the regulation of recombinant protein expression in Pichia pastoris (P. pastoris). PAOX1 is tightly repressed by the presence of glycerol in the culture medium; thus, glycerol must be exhausted before methanol can be taken up by P. pastoris and the expression of the heterologous protein can be induced. In this study, a candidate glycerol transporter (GT1, GeneID: 8197545) was identified, and its role was confirmed by further studies (e.g. bioinformatics analysis, heterologous complementation in Schizosaccharomyces pombe (S. pombe)). When GT1 is co-expressed with enhanced green fluorescent protein (EGFP), it localizes to the membrane and S. pombe carrying gt1 but not the wild-type strain can grow on medium containing glycerol as the sole carbon source. The present study is the first to report that AOX1 in the X-33gt1 mutant can achieve constitutive expression in medium containing glycerol; thus, knocking down gt1 can eliminate the glycerol repression of PAOX1 in P. pastoris. These results suggest that the glycerol transporter may participate in the process of PAOX1 inhibition in glycerol medium