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The article proposes a convex distributed robust model predictive control algorithm for collision avoidance in multi‐agent systems with additive disturbances, which utilizes the concept of tube model predictive control to address the disturbances. To tackle the coupled collision avoidance constraints, each agent integrates assumed nominal position and input trajectories from its neighbors, rather than relying on actual ones. Compatibility constraints are then designed using the normal vector of the constructed separating hyperplanes for collision avoidance and the residual collision avoidance margin of the optimal solutions at the last time step to restrict deviations between assumed and actual trajectories and ensure consistency among the agents. The nonconvex collision and obstacle avoidance constraints are convexified using the concept of safe sets, transforming them into time‐varying closed polyhedral constraints while accounting for the impact of disturbances. Particularly, the residual collision avoidance margin is incorporated into the construction of safe sets for the satisfaction of coupled collision avoidance constraints. Consequently, the original collision avoidance optimal control problems can be efficiently and simultaneously solved for all agents using standard quadratic programming techniques. Under the design of local terminal constraint sets for each agent, the proposed algorithm ensures a rigorous analysis of robust constraint satisfaction for collision avoidance constraints, as well as an assessment of recursive feasibility and closed‐loop stability. The effectiveness of the algorithm is demonstrated through an illustrative example, and simulation results validate its ability to successfully achieve collision and obstacle avoidance even in the presence of disturbances. [ABSTRACT FROM AUTHOR]

This paper proposes a locally convexified rigid tube model predictive control for obstacle avoidance for linear, discrete‐time, systems subject to additive, bounded disturbances and state and control constraints. The inherently nonconvex obstacle avoidance constraints are locally convexified and converted into closed polyhedral constraints by deploying recent notions of safe sets and tubes. The proposed method leverages these recent notions of safe sets and tubes to reformulate the original nonconvex optimization problem for obstacle avoidance within the context of disturbances into a computationally highly efficient, strictly convex quadratic programming problem. In order to analyze the separation between a predicted state set and each obstacle avoidance constraint set, we employ the Euclidean distance between these two sets and the radius of the Chebyshev ball of their intersection. In the strict separation case, the separating hyperplanes are constructed by utilizing the separation theorem for convex sets, while in the weak separation case, the construction of separating hyperplanes is achieved through the use of the separation theorem and the properties of convex cones. The proposed method provides guarantees of strong system theoretic properties such as robust recursive feasibility, robust positive invariance and robust stability of the controlled uncertain system. A simulation example is also provided to numerically verify the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Aldehyde oxidases (AOXs) are a group of metabolic enzymes that play critical roles in the degradation of xenobiotics and chemicals. However, the physiological function of this enzyme in insects remains poorly understood. In this study, three TcAOX genes (TcAOX1 , TcAOX2 , TcAOX3) were identified and characterized from Tribolium castaneum genome. Spatiotemporal expression profiling showed that TcAOX1 expression was most highly expressed at the early pupal stage and was predominantly expressed in the antennae of adults, indicating that TcAOX1 was involved in the degradation of chemical signals; TcAOX2 expression was most highly expressed at the late pupal stage and was mainly expressed in the fat body, epidermis of larvae and adults, respectively; and TcAOX3 expression was in all stages and was primarily expressed in the head of adults. Moreover, the transcripts of TcAOX2 and TcAOX3 were significantly induced after exposure to plant oil, and RNA interference (RNAi) targeting of each of them enhanced the susceptibility of beetles to this plant toxicant, suggesting that these two genes are associated with plant toxicant detoxification. Intriguingly, knockdown of the TcAOX1 led to reductions in female egg-laying but unchanged the hatchability and the development of genital organs, suggesting that this gene may mediate fecundity by effecting the inactivation of chemical signals in T. castaneum. Overall, these results shed new light on the function of AOX genes in insects, and could facilitate the development of research on pest control management. [ABSTRACT FROM AUTHOR]

Uridine diphosphate glucosyltransferases (UGTs), which are phase II detoxification enzymes, are found in various organisms. These enzymes play an important role in the detoxification mechanisms of plant allelopathy and in insects. Artemisia vulgaris L. (Asterales: Asteraceae: Artemisia) essential oil has strong contact toxicity to Tribolium castaneum Herbst (Coleoptera: Tenebrionidae) larvae. However, the effect of A. vulgaris essential oil on UGTs is unclear. In this study, A. vulgaris essential oil was shown to significantly induce the expression of the TcUgt86Dg transcript. Furthermore, treatment of TcUgt86Dg -silenced individuals with A. vulgaris essential oil resulted in higher mortality than for the control individuals, indicating that TcUgt86Dg is involved in detoxification of A. vulgaris essential oil in T. castaneum. The developmental expression profile showed that the expression of TcUgt86Dg in late adults was higher than in other developmental stages. Furthermore, the expression profile in adult tissues revealed higher expression of TcUgt86Dg in the head, antenna, fat body, and accessory gland than in other tissues. These data show that TcUgt86Dg may be involved in the metabolism of exogenous toxins by T. castaneum ; thus, our results have elucidated one possible mechanism of resistance to A. vulgaris essential oil and provide a theoretical basis for a control scheme for T. castaneum. [ABSTRACT FROM AUTHOR]

Tribolium castaneum (T. castaneum) is a worldwide pest of stored grain that mainly harms flour, and not only causes serious loss of flour quality but also leads to deterioration of flour quality. Chemical detection plays a key role in insect behavior, and the role of odorant-binding proteins (OBPs) in insect chemical detection has been widely studied. However, the mechanism of OBPs in insect defense against exogenous toxic substances is still unclear. In this study, biochemical analysis showed that eugenol, the active component of A. vulgaris essential oil, significantly induced the expression of the OBP gene OBPC12 from T. castaneum (TcOBPC12). The mortality of late larvae treated with eugenol was higher than that of the control group after RNA interference (RNAi) against TcOBPC12 , which indicates that the OBP gene is involved in the eugenol defense mechanism and leads to a decrease in sensitivity to eugenol. Tissue expression profiling showed that the expression of TcOBPC12 in the epidermis, hemolymph, and intestine was higher than in other larval tissues, and TcOBPC12 was expressed mainly in the epidermis, head, and fat body of adults. The developmental expression profile showed that the expression of TcOBPC12 in late eggs, early and late larval stages, and late adult stages was higher than in other developmental stages. These data suggest that TcOBPC12 may be involved in the absorption of exogenous toxic substances by the larvae from T. castaneum. Our results provide a theoretical basis for the metabolism and degradation mechanism of exogenous toxic substances and help explore more potential target genes of insect pests. [Display omitted] • The expression of TcOBPC12 was up-regulated at 60 and 72 h after eugenol treatment. • TcOBPC12 was highly expressed in late eggs, early and late larval, and late adult stages. • TcOBPC12 was abundant in the epidermis, hemolymph and intestine of the late larval. • TcOBPC12 was more in the epidermis, head and fat body of the early adult. • RNAi of TcOBPC12 increased the mortality of late larvae after eugenol treatment. [ABSTRACT FROM AUTHOR]

Due to the absence of nerves and blood vessels in articular cartilage, its regeneration and repair present a significant and complex challenge in osteoarthritis treatment. Developing a specialized physical and chemical microenvironment supporting cell growth has been difficult in cartilage grafting, especially when aiming for comprehensive biomimetic solutions. Based on previous research, we have designed a tissue-engineered decellularized living hyaline cartilage graft (dLhCG). The study developed a method to improve the hydrophilicity and stiffness of scaffolds by employing chemical grafting techniques and designed a decellularized hyaline cartilage phenotype matrix scaffold for tissue engineering. Here, we reported a method using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride /N-hydroxysuccinimide (EDC/NHS) to achieve the grafting of chondroitin sulfate (CS) onto dLhCG, ultimately producing a tissue-engineered hyaline cartilage graft with the CS (dLhCG/CS). Young's modulus measurements revealed that the cross-linked scaffolds exhibited enhanced mechanical properties. We implanted the cross-linked dLhCG/CS scaffolds into the trochlear region of rat joints and evaluated their functionality through histological analysis and biomechanical tests. After 12 weeks, the dLhCG/CS scaffolds demonstrated excellent bioinductive activity comparable to dLhCG. The regenerated tissue effectively maintained a hyaline cartilage phenotype and exhibited similar mechanical properties, playing a crucial role in cartilage regeneration., (© 2024 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved.)