Secure control for remote networked stochastic systems via integral sliding mode.

This paper deals with the secure control problem for a class of networked stochastic systems with false data injection attacks via an integral sliding mode control technique. The networked control system is with a hierarchical structure, and the main controller and a remote controller are considered to realize the secure control against false data injection attacks on the network between a main controller and the plant. A mode-shared event-triggering controller is designed as the main controller, by utilizing a time delay approach. An input-output model based on a two-term approximation is applied to cope with the formulated time-varying delay. Then, the scaled small gain theory is employed to analyze the stability of the resulting system. Sufficient conditions on ensuring the desired system performance are derived and then the controller parameters are synthesized. Moreover, an elaborated sliding mode control law is proposed for the desired secure control action. Finally, two simulation examples are permitted to verify the effectiveness of the theoretical derivations.

Microplastics affect C, N, and P cycling in natural environments: Highlighting the driver of soil hydraulic properties.

As microplastics (MPs) are organic polymers with a carbon-based framework, they may affect nutrient cycling. Information regarding how MPs influence N, P, and C cycling and the underlying driving force remains lacking. N, P, and C cycling induced by soil hydraulic properties under MPs exposure (including polyethylene (PE), polyvinyl chloride (PVC), polystyrene (PS), polypropylene (PP)) in the natural environment were investigated in this study. MPs exposure increased the soil water content (11.2-84.5%) and reduced bulk density (11.4-42.8%); soil saturated hydraulic conductivity increased by 7.3-69.4% under PP and PE exposure. MPs exposure led to increases in available phosphorus, NO3--N, NH4+-N, and soil organic matter; the bacterial communities related to N and C cycling were significantly changed. Expression levels of soil N and C cycling-related genes were enhanced under low concentrations (0.5% and 2%) of MPs, except PVC; consequently, soil nitrogen storage and organic carbon storage increased by 12-75% and 6.7-93%, respectively. Correlation analyses among soil hydraulic properties, bacterial communities, and functional genes related to nutrient cycling revealed that soil hydraulic properties (including soil water content, saturated water capacity, and soil saturated hydraulic conductivity) were the dominant factors affecting soil N and C storage under MPs exposure.

Dissipativity-Based Sliding-Mode Control of Cyber-Physical Systems Under Denial-of-Service Attacks.

In this article, we investigate the problem of the dissipativity-based resilient sliding-mode control design of cyber-physical systems with the occurrence of denial-of-service (DoS) attacks. First, we analyze the physical layer operating without DoS attacks to ensure the input-to-state practical stability (ISpS). The upper bound of the sample-data rate in this situation can be identified synchronously. Next, for systems under DoS attacks, we present the following results: 1) combined with reasonable hypotheses of DoS attacks, the ISpS as well as dissipativity of the underlying system can be guaranteed; 2) the upper bound of the sample-data rate in the presence of DoS attacks can be derived; and 3) the sliding-mode controller is synthesized to achieve the desired goals in a finite time. Finally, two examples are given to illustrate the applicability of our theoretical derivation.

A Variant of Leptin Gene Decreases the Risk of Gastric Cancer in Chinese Individuals: Evidence from a Case-Control Study.

BACKGROUND: A host of studies have explored the potential connection between leptin (LEP) G19A polymorphism and the risk of cancers, but the relationship between gastric cancer (GC) susceptibility and LEP G19A polymorphism was not revealed before. The aim of this study was to investigate this relationship in Chinese Han population. METHODS: Thus, this case-control study with 380 GC cases and 465 controls was designed to unearth the link between LEP G19A polymorphism and GC susceptibility. Genotyping was accomplished by a custom-made 48-Plex SNP scanTM kit. Relative LEP gene expression was detected by real-time reverse transcription-polymerase chain reaction. RESULTS: LEP G19A polymorphism was shown to relate with a decreased risk of GC. Subgroup analyses uncovered significant connections in the males, nondrinkers, and those at age <60 years. G19A polymorphism was also linked with tumor size and location and pathological type of GC. Last, LEP gene expression in gastric tissues was considerably less than in control tissues. CONCLUSION: This study shows that G19A polymorphism of LEP gene is linked with a lower risk of GC in the tested Chinese Han individuals.