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Olfaction plays a crucial role for arthropods in foraging, mating, and oviposition. The odorant‐binding protein (OBP) gene is considered one of the most important olfactory genes. However, little is known about its functions in predatory mites. Here, we used Neoseiulus barkeri, an important commercialized natural pest control, to explore the chemosensory characteristics of OBP. In this study, N. barkeri was attracted by methyl salicylate (MeSA) and showed higher crawling speeds under MeSA treatment. Then, we identified and cloned an OBP gene named Nbarobp2 and analyzed its expression profiles in the predatory mite. Nbarobp2 was 663 bp, was highly expressed in larval and nymphal stages, and was significantly upregulated in N. barkeri under MeSA treatment. Nbarobp2 encoded 202 amino acid residues with a molecular weight of 23 kDa (after removing the signal peptide). Sequence comparisons revealed that the OBPs in Arachnida shared 6 conserved cysteine sites, but were distinguishable from the OBPs of Insecta on the phylogenetic tree. RNA interference, Western blotting, and binding affinity assays further proved that Nbarobp2 was involved in volatile perception in predatory mites. This study shed light on the functional characteristics of OBPs in predatory mites, providing a new insight for better biological control. [ABSTRACT FROM AUTHOR]

Summary: Acid mine drainage (AMD) generated by rare earth elements (REEs) deposits exploration contains high concentrations of REEs, ammonium and sulfates, which is quite different from typical metallic AMD. Currently, microbial responses and ecological functions in REEs‐AMD impacted rivers are unknown. Here, 16S rRNA analysis and genome‐resolved metagenomics were performed on microbial community collected from a REEs‐AMD contaminated river. The results showed that REEs‐AMD significantly changed river microbial diversity and shaped unique indicator species (e.g. Thaumarchaeota, Methylophilales, Rhodospirillales and Burkholderiales). The main environmental factors regulating community were pH, ammonium and REEs, among which high concentration of REEs increased REEs‐dependent enzyme‐encoding genes (XoxF and ExaF/PedH). Additionally, we reconstructed 566 metagenome‐assembled genomes covering 70.4% of identifying indicators. Genome‐centric analysis revealed that the abundant archaea Thaumarchaeota and Xanthomonadaceae were often involved in nitrification and denitrification, while family Burkholderiaceae were capable of sulfide oxidation coupled with dissimilatory nitrate reduction to ammonium. These indicators play crucial roles in nitrogen and sulfur cycling as well as REEs immobilization in REEs‐AMD contaminated rivers. This study confirmed the potential dual effect of REEs on microbial community at the functional gene level. Our investigation on the ecological roles of indicators further provided new insights for the development of REEs‐AMD bioremediation. [ABSTRACT FROM AUTHOR]

Companies generally set a standard color for product color design to enhance the corporate brand image. When a given color and the planned combination of given areas contain multiple constraints, the exhaustive process that has traditionally been used to obtain the optimal color scheme is often time consuming. Therefore, this study proposes the use of binary programming theory to solve the problem of product color planning with multiple constraints. In this research, binary programming theory is first used to determine the variables of the product color matching design. Thereafter, multiple constraints are established based on various color requirements from the product color matching design, following which the color matching design goal is determined according to the aesthetic experience of the designer on the color matching design. Finally, the constrained formula is converted into a language that can be recognized by the Matlab software and input into the Optimization Tool application to calculate the final color planning scheme. The color design of an intelligent assembly product in the rail transit field is used as an example to demonstrate the operation process of the proposed solution, and the calculation results are verified by subjective questionnaires. The results reveal that the proposed method can effectively solve the problem of product color matching design with multiple constraints, can improve the efficiency of product color matching design with multiple constraints, and offers certain reliability and practicability. [ABSTRACT FROM AUTHOR]

Microplastic pollution has become an increasingly pervasive issue worldwide, but little is known about its effects on the soil environment. A soil microcosm experiment was conducted using low‐density polyethylene microplastics to estimate the effect of microplastic pollution on soil nutrient cycling and the soil microbial community structure. The results showed that microplastic addition significantly promoted soil carbon dioxide emissions but not soil nitrous oxide emissions. Soil pH, dissolved organic carbon, ammonia nitrogen, the contents of total phospholipid fatty acid (PLFA), and the ratios of gram‐positive bacteria to gram‐negative bacteria and saturated to monounsaturated PLFAs significantly increased. In addition, nitrate nitrogen and the ratios of fungi to bacteria, total iso‐branched fatty acids to total anteiso‐branched fatty acids, and cyclopropyl to precursor significantly decreased with increasing microplastic addition. The addition of microplastics decreased the abundance of ammonia oxidizing bacteria and nitrite reductase (nirS) but had little effect on the functional genes of ammonia oxidizing archaea, nitrite reductase (nirK), and nitrous oxide reductase. A principal coordinate analysis of the bacterial 16S ribosomal RNA gene and fungal internal transcribed spacer in the microplastic addition treatments revealed that the bacterial and fungal communities formed an obvious cluster. The average abundance of some microbial species with tolerance and degradability to microplastics, such as Nocardioidaceae, Amycolatopsis, Aeromicrobium, Cytophagaceae, Betaproteobacteria, Rhodoplanes, and Mortierella, in the microplastic addition treatments was significantly higher than that of the control treatment. The results suggested that microplastics have obvious influences on microbial communities and may affect global carbon and nitrogen cycles. Environ Toxicol Chem 2021;40:352–365. © 2020 SETAC [ABSTRACT FROM AUTHOR]

BACKGROUND In fluctuating climatic environments, heat acclimation in predatory mites is a superior adaptation strategy for effective agricultural pest management and can be used to enhance the abilities critical in biological control efficiency. We investigated the regulatory mechanism governing the remarkable plastic response of thermotolerance in a high‐temperature adapted strain (HTAS) and discerned the differences in the defensive reactions between the HTAS and the conventional strain (CS) in the predatory mite Neoseiulus barkeri. RESULTS: At 42 °C, the relative expression levels of four identified HSP70 genes increased rapidly in both N. barkeri strains; meanwhile the expression of NbHSP70‐1 and NbHSP70‐2 in CS sharply decreased after 4 h, displaying a distinct contrast with the remaining elevated expression in HTAS. Western blot analysis showed that the protein level of NbHSP70‐1 in CS was dramatically elevated at 0.5 h and decreased at 6 h at 42 °C. Conversely, in HTAS, NbHSP70‐1 was constantly induced and peaked at 6 h at 42 °C. Furthermore, HSP70 suppression by RNAi knockdown had a greater influence on the survival of HTAS, causing a higher mortality under high temperature than CS. Finally, the recombinant exogenous NbHSP70‐1 protein enhanced the viability of E. coli BL21 under a lethal temperature of 50 °C. CONCLUSION: Sustained accumulation of HSP70 proteins results in predatory phytoseiid mites with the thermotolerance advantage that could promote their biological control function to pests. The divergent constitutive regulation of HSP70 to a thermal environment is conducive to the flexible adaptability of predators in the higher trophic level to trade off under extremely adversity stress. [ABSTRACT FROM AUTHOR]

We report a novel type of full‐screen LCD with an under‐display camera (UDC) optical structure. The structure uses different pixel design to make a high transmittance for photographing. It can achieve a true full‐screen display by hiding the camera. It has a better user experience than traditional full‐screen smart phone with a notch or hole area in the screen. [ABSTRACT FROM AUTHOR]