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Consequently, ongoing and future pollution with microplastic fibers may disturb the functioning of aquatic ecosystems. The present review outlines the current state of knowledge on microplastic fiber abundance in nature, bioavailability, and impacts on aquatic animals. Based on these findings, we recommend inclusion of microplastic fibers in prospective monitoring studies, discuss appropriate methods, and propose to conduct exposure studies with - as well as risk assessments of - these underestimated pollutants.Random and systematic change analysis is gradually becoming a common method for effectively detecting land use change signals from land transition matrix, but most researches focus only on the change characteristics at the transition level. This paper attempted to distinguish random and systematic changes at the category level, and to clarify the meanings of these two types of changes, as well as their indicative significances of change causes. This paper first calculated the random expected value of change area at the category level, and the deviation of the actual change area from the expected value. Then we proposed a method for setting a threshold of the deviation to clearly distinguish random and systematic changes. This method could eliminate the influence of land use classification errors on the distinction. Through analyzing the mathematical formulas of random expected area, this paper further clarified the meanings of random and systematic changes as well as their indicative significances to change causes. Land use change in Mu Us area of China was used as a case study. Practice showed that detecting and analyzing the random and systematic signals at the category level could accurately determine the change trend of land use, which could help to explore the relationship between land use change and external influences, especially human activities.Temperature sensitivity of soil extracellular enzyme activity (EEA), indicated by the temperature coefficient Q10, is used to predict the effect of temperature on soil carbon (C), nitrogen (N), and phosphorus (P) cycling. At present, we lack understanding of elevation and soil depth variations in Q10 of EEA. Here, we measured the Q10 of three enzymes participating in C- (β-1,4-glucosidase, BG), N- (leucine aminopeptidase, LAP), and P- (acid phosphatase, AP) cycling along a vertical grassland belt of China. Soils from five depths (0-10, 10-20, 20-40, 40-60, and 60-100 cm) were sampled from three elevations (low, less then 1000 m; middle, 1000-2000 m; high, 2000-3000 m) and incubated at four temperatures (5, 15, 25, 35 °C). The average Q10 of soil EEA ranged from 0.97 to 1.11 and the Q10 of LAP was higher than that of BG and AP. Generally, the Q10 of BG and LAP both increased from low to middle elevation and then decreased, while the Q10 of AP was stable. Moreover, the effect of soil depth on Q10 of EEA was weakened from low elevation to high elevation, and the factors driving Q10 of soil EEA changed with elevation. This study improved the understanding of the vertical pattern of Q10 of soil EEA in water-limited ecosystems, and highlighted that elevation could regulate the effect of soil depth on Q10 of EEA.Silver nanoparticles (AgNPs) may reach the soil compartment via sewage sludge or nanoagrochemical applications. Understanding how NPs interact with biological systems is crucial for an accurate hazard assessment. Therefore, this study aimed at determining the Ag toxicokinetics in the mealworm Tenebrio molitor, exposed via Lufa 2.2 soil or via food to different Ag forms (uncoated 50 nm AgNPs, paraffin coated 3-8 nm and PVP-stabilised 60 nm, Ag2S NPs 20 nm, and ionic Ag). Mealworms were exposed for 21 days followed by a 21-day elimination phase (clean soil/food). A one-compartment kinetics model with inert fraction (simulating a storage compartment, where detoxified forms are located) was used to describe Ag accumulation. Fully understanding the uptake route in mealworms is difficult. For that reason several approaches were used, showing that food, soil and pore water all are valid uptake routes, but with different importance. Silver taken up from soil pore water or from soil showed to be related to Ag dissolution in soil pore water. In general, the uptake and elimination rate constants were similar for 3-8 nm and 60 nm AgNPs and for AgNO3, but significantly different for the uncoated 50 nm AgNPs. Upon food exposure, uptake rate constants were similar for 50 nm AgNPs and AgNO3, while those for 60 nm and 3-8 nm AgNPs and for Ag2S NPs also grouped together. NP exposure in soil appeared more difficult to characterize, with different patterns obtained for the different NPs. But it was evident that upon soil or food exposure, particle characteristics highly affected Ag bioavailability and bioaccumulation. Although Ag2S NPs were taken up, their elimination was faster than for other Ag forms, showing the lowest inert fraction. The significantly different elimination rate constants suggest that the mechanism of elimination may not be the same for different AgNPs either.As an essential trace element, selenium can be used to protect crops from pests, while, in nature, most crops cannot accumulate enough selenium from the soil to reach the effective dose for pest control. In this study, carbon dots modified with arginine in nano-scale was prepared and characterized, then, it was combined with sodium selenite to form selenium-carbon dots (Se-CDs). Function evaluation of Se-CDs showed that it could increase the absorption of selenium in plant leaves, promote the control efficiency of fenpropathrin, and protect plant from damage caused by Tetranychus cinnabarinus. In addition, we found that expressions of P450 genes and activity of P450 enzyme both decreased in selenium treated mites. In vivo, the acaricidal activity of fenpropathrin increased significantly when one of the P450 genes, CYP389B1, was silenced, and the recombinant protein of CYP389B1 could metabolize fenpropathrin in vitro. click here The results suggested that inhibiting the expression of P450 gene and repressing the detoxification of T. cinnabarinus was the molecular mechanism that how selenium promoted the acaricidal activity of fenpropathrin. The application of Se-CDs in the field will decrease the use of chemicals acaricides, reduce chemical residues, and ensure the safety of agricultural products.