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The overtaking behavior of individuals under anxious panic is a major causative factor of crowded trampling accidents. In order to simulate the overtaking behavior of individuals experiencing anxiety and panic in a single-exit room within a normal pedestrian flow, an improved social force model is proposed to simulate crowd movement at local medium and high density through introducing the bypass overtaking mechanism, the side overtaking mechanism, and the side avoidance mechanism generated by association. The numerical simulation verifies the model's validity. The effect of the size and number of overtaking individuals on the pedestrian flow are explored. The results show that the new model can simultaneously reproduce a variety of overtaking behaviors and their associated behaviors in line with reality. The larger size of the overtaking individuals are, the easier it is to produce overtaking behaviors and the more difficult it is to overtake. With the increase of the number of overtaking individuals, the evacuation time becomes longer, but there is no linear relationship between them. When the initial pedestrian density is 0. 37 ped / m 2 , with time evolution, the appearance frequency of local density greater than 0. 8 ped / m 2 suddenly increases, and the comfort and safety of pedestrian movement decreases. The results of this paper can enrich the social force simulation model of pedestrian flow and provide a theoretical guidance for the evacuation of pedestrian flow with a few overtaking individuals in the room. • A novel social force model is used to describe individuals' overtaking behavior. • The overtaking mechanism and the side avoidance mechanism are introduced. • The effect of the size and number of overtaking individuals are explored. • The larger size of pedestrians are, the easier it is to produce overtaking behavior. [ABSTRACT FROM AUTHOR]

Nanhui Dongtan Wetland is an important part of Yangtze Estuary Wetland, and its species diversity has been affected by reclamation in recent years. To increase the diversity of species in reclamation areas, stock enhancement was implemented in the Nanhui Dongtan Wetland in May 2020 as a method of ecological restoration. We investigated macrobenthos before and after release, analysed changes in the macrobenthos and evaluated the ecological health of the sampled area. The diversity index showed species were more abundant and community structure were more diversified after release. Functional groups and redundancy analysis showed that the effects of stock enhancement on macrobenthos in Nanhui Dongtan wetland may be based on changes in secondary productivity. Stock enhancement may promote the resistance of macrobenthic communities to organic pollution without negatively affecting ecological health. As a method of ecological restoration, stock enhancement will play a positive role in the restoration of macrobenthic communities. [Display omitted] • After release, macrobenthic species were more abundant and community structure became more complex in sampling area. • Effects of stock enhancement on macrobenthos in Nanhui Dongtan wetland may be based on changes in secondary productivity. • Stock enhancement may promote resistance of macrobenthic communities to organic pollution without harming ecological health. [ABSTRACT FROM AUTHOR]

Haloxyfop-P-methyl is used extensively in agricultural production, and its metabolites in soil have potentially toxic effects on aquatic ecosystems. In this study, we explored the toxicity of haloxyfop-P-methyl on Chiromantes dehaani. The results of the 21-day toxicity test showed that haloxyfop-P-methyl decreased the weight gain (WG), specific growth rate (SGR) and hepatosomatic index (HSI). In glucose metabolism, haloxyfop-P-methyl reduced pyruvate, lactate, lactate dehydrogenase and succinate dehydrogenase, but enhanced glucose-6-phosphate dehydrogenase and hexokinase. Furthermore, expression of glucose metabolism-related genes was upregulated. We cloned the full-length CdG6PDH gene, which contains a 1587 bp ORF that encoded a 528 amino acid polypeptide. In antioxidant system, haloxyfop-P-methyl increased glutathione, thioredoxin reductase and thioredoxin peroxidase activities and activated the Nrf2/ARE pathway through upregulation of ERK , JNK , PKC and Nrf2. In immunity, low concentrations haloxyfop-P-methyl, or short-term exposure, upregulated the expression of immune-related genes and enhanced immune-related enzymes activity, while high concentrations or long-term exposure inhibited immune function. In summary, haloxyfop-P-methyl inhibited the growth performance, disrupted glucose metabolism, activated the antioxidant system, and led to immunotoxicity. The results deepen our understanding of the toxicity mechanism of haloxyfop-P-methyl and provide basic biological data for the comprehensive assessment of the risk of haloxyfop-P-methyl to the environment and humans. [Display omitted] • Haloxyfop-P-methyl inhibited growth performance and disrupted glucose metabolism. • G6PDH was analyzed and played a positive role against haloxyfop-P-methyl exposure. • Oxidative stress induced by haloxyfop-P-methyl exposure suppressed immune function. • Haloxyfop-P-methyl activated the Nrf2/ARE pathway to regulated antioxidant defense. • The PPP was stimulated and anaerobic glycolysis was inhibited by haloxyfop-P-methyl. [ABSTRACT FROM AUTHOR]

Haloxyfop-P-methyl is widely used in controlling gramineous weeds, including the invasive plant Spartina alterniflora. However, the mechanism of its toxicity to crustaceans is unclear. In this study, we adopted transcriptome analysis combined with physiologic changes to investigate the response of estuarine crab (Chiromantes dehaani) to haloxyfop-P-methyl. The results showed that the median lethal concentration (LC 50) of C. dehaani to haloxyfop-P-methyl at 96 h was 12.886 mg/L. Antioxidant system analysis indicated that MDA, CAT, GR, T-GSH, and GSSG might be sensitive biomarkers that characterize the oxidative defense response of the crab. In total, 782 differentially expressed genes were identified, including 489 up-regulated and 293 down-regulated genes. Glutathione metabolism, detoxification response and energy metabolism were significantly enriched, revealing the potential toxic mechanism of haloxyfop-P-methyl to C. dehaani. These results provide a theoretical foundation for further research on haloxyfop-P-methyl toxicity to crustaceans. [Display omitted] • The 96-h LC 50 of haloxyfop-P-methyl on C. dehaani was 12.886 mg/L. • Haloxyfop-P-methyl induced oxidative stress and activated antioxidant response. • Detoxification response related genes contribute to the haloxyfop-P-methyl tolerance. • Haloxyfop-P-methyl disrupted energy metabolism. [ABSTRACT FROM AUTHOR]

This study compared the community structure of macrobenthos in bare tidal areas and vegetated regions under two reclamation patterns, fully enclosed and opened reclamation, in Yangtze wetland, China. Compared with fully enclosed reclamation areas, opened reclamation areas had higher water salinity, higher number of species and abundance, and less disturbed habitat health status. Compared with bare tidal areas, vegetated regions were more suitable for the survival of macrobenthos and its habitat health status was more stable. Salinity, pH and larger soil particle diameter were positively associated with macrobenthic diversity, while total nitrogen and total phosphorus were negatively associated. Overall, compared with fully enclosed reclamation and vegetated regions, opened reclamation and bare tidal areas had less negative effects upon macrobenthic community and habitat health. Opened reclamation is preferred for wetland reclamation, and planting indigenous plants and releasing species adapted to fresh water is beneficial to the restoration of macrobenthic communities. [Display omitted] • The ecological health in fully enclosed reclamation areas was more disturbed than in opened reclamation areas. • Salinity desalination was a key factor in the decline of species richness of macrobenthos. • Vegetation helped to improve the effects of wetland reclamation on macrobenthos communities. • Larger soil particle diameter were positive factors for biodiversity of macrobenthos. • When large-scale reclamation of wetland was unavoidable, opened reclamation is preferable. [ABSTRACT FROM AUTHOR]

Plastic pollution in the form of nanoplastics poses a global threat to aquatic ecosystems and the organisms inhabiting them. However, few studies have been conducted on the effects of nanoplastic exposure on reproductive development in crustaceans. In order to address this issue, juvenile oriental river prawns (Macrobrachium nipponense) were exposed to different concentrations of 75-nm polystyrene nanoplastics (0, 5, 10, 20, 40 mg/L) for 28 days. In order to study the regulation of reproduction-related genes in the presence of nanoplastics, the Wee1 protein kinase gene (Wee1) and OTU domain ubiquitin aldehyde binding protein gene (OTUB) were selected. In this study, for the first time, the full-length cDNA of Mn-Wee1 and Mn-OTUB were cloned from M. nipponense. Homologous alignments revealed that Mn-Wee1 had a highly conserved function-critical sequence, and that Mn-OTUB was more closely related to OTUB1 than OTUB2. With increasing concentration of nanoplastics, the expression of both genes increased initially, then decreased. The inhibition of expression of Wee1 and OTUB occurred in 40 mg/L group, respectively. Analysis of the data also indicated that nanoplastic exposure might have differing effects on gene expression in M. nipponense male and female reproductive organs. • Genes related to reproductive developmental expression were evaluated from shrimp exposed to polystyrene nanoplastics. • The Wee1 and OTUB genes were cloned for the first time, and the molecular characteristics were analyzed. • The effect of polystyrene nanoplastics exposure on reproductive development might be different in male and female shrimp. Our results identify potential nanoplastic toxicity on expression of two genes related to reproductive development in aquatic organisms. [ABSTRACT FROM AUTHOR]

• The curdlan biosynthesis mechanism can be determined based on whole-genome analysis. • Mutant CGMCC 11546 produced 1.34-fold more curdlan than the WT strain. • The maximum curdlan production was 47.97 ± 0.57 g/L (16 % increase) after optimization. • Deletion of exoK and exsH increased the gel strength and molecular weight of curdlan. • Noodles supplemented with curdlan from Δ exoK-exsH had excellent eating quality. Curdlan is a bacterial, water-insoluble, linear homopolysaccharide that has been widely used in the food industry. In this study, genome information of strain CGMCC 11546, a UV-induced high-yield mutant of the model curdlan-producing strain Agrobacterium sp. ATCC 31749, was used to investigate the molecular mechanism of curdlan biosynthesis. The maximum curdlan yield of 47.97 ± 0.57 g/L was obtained from strain CGMCC 11546 by using optimal media containing 60 g/L sucrose, 6 g/L yeast, 2 g/L KH 2 PO 4 , 0.4 g/L MgSO 4 ·7H 2 O, 2 g/L CaCO 3 , 0.1 g/L FeSO 4 ·7H 2 O, 0.04 g/L MnSO 4 , and 0.02 g/L ZnCl 2 at 30 °C and 280 rpm after 96 h of fermentation. The gel strength of curdlan was improved by 41 % by knocking out the β-1,3-glucanase genes exoK and exsH of strain CGMCC 11546. Furthermore, the application of curdlan from the Δ exoK-exsH strain in noodles significantly improved the eating quality of both raw and cooked noodles. [ABSTRACT FROM AUTHOR]

Two isoforms of Glutathione S-Transferase (GST) genes, belonging to mu (Dp-GSTm1 and Dp-GSTm2) and sigma (Dp-GSTs1 and Dp-GSTs2) classes, were cloned and characterised in the freshwater Daphnia pulex. No signal peptide was found in any of the four GST proteins, indicating that they were cytosolic GST. A highly conserved glutathione (GSH) binding site (G-site) occurred in the N-terminal sequence, and a substrate binding site (H-site), interacting non-specifically with the second hydrophobic substrate, was present in the C-terminal. A Tyr residue, for the stabilization of GSH, was found to be conserved in the analysed sequences. The secondary and tertiary structures indicated that these genes possess the typical cytosolic GST structure, including a conserved N-terminal domain with a βαβαββα motif. The μ loop (NVGPAPDYDR and NFIGAEWDR in Dp-GSTm1 and Dp-GSTm2, respectively) was identified between the βαβ (β1α1β2) and αββα motifs (α2β3β4α3) in the N-terminal domain. The expressions of Dp-GSTs1 , Dp-GSTs2 , and Dp-GSTm1 were higher in other age groups compared to the newly-born neonates (1 d); however, the expression of Dp-GSTm2 first increased and then decreased with age. Gene expression was significantly reduced by high concentration (1 and 2 mg/L) of 75 nm polystyrene nanoplastic. However, nanoplastic exposure at the predicted environmental concentration (1 μg/L) had a low effect. Exposure of mothers to nanoplastic (1 μg/L) elevated the Dp-GSTs2 level in their neonates. These results improve our understanding on the response of different types of Daphnid GST to environmental contaminants, especially nanoplastic. • Four GST genes of D. pulex exhibited all the features typical to the GST family. • Glutathione S-Transferase played a positive role against nanoplastic exposure. • Exposure of mothers to nanoplastic elevated the Dp-GSTs2 level in their neonates. [ABSTRACT FROM AUTHOR]