Considerable attention has been paid to the occurrence and abundance of antibiotic resistance genes (ARGs) in aquatic environments. However, the temporal variation and dissemination of ARGs in ...aquaculture environments and reared organisms need further study. This study investigated the abundance and diversity of ARGs and bacterial community in water source, shrimp pond water, sediment, and shrimps during the rearing period in Pearl River Delta region, South China. The results showed that sul1, qnrD, cmlA, and floR were the predominant ARGs in the aquaculture samples. A trend of decreasing abundance of ARGs was observed for pond water samples during the rearing period, whereas an increasing trend was observed in the sediment and shrimp samples. The total concentration of ARGs in water source was significantly higher than that in shrimp pond water (p<0.05). A significant negative correlation was found between the total concentrations of ARGs in pond waters and sediments (p<0.01). The total abundances of ARGs in intestinal tract of adult shrimps were 4.48–19.0 times higher than those in juvenile shrimps. Similar to water source and pond water, cmlA and sul1 were the predominant ARGs in shrimp intestinal tract. The bacterial community in the shrimp intestinal tract changed greatly from juvenile to adult. The results of the present study indicated that the abundances of ARGs in aquaculture varied temporally during the rearing period. Water source was an important medium disseminating ARGs to the aquaculture environments and reared organisms. Sul1 could be used as a potential indicator for ARGs in both water and sediment in aquaculture in the estuary of the Pearl River Delta, South China. This study represents a case study for the temporal variation of abundance and dissemination of ARGs in aquaculture and is a reference for potential risks to food safety and human health.
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•Water source disseminated ARGs to aquaculture environments and reared organisms.•The abundances of ARGs in aquaculture varied temporally during the rearing period.•Sul1 is a potential indicator for ARGs in water and sediment in aquaculture.•ARG prevalence was higher in adult than in juvenile shrimp intestinal tracts.•Bacterial community in the intestinal tract changed greatly from juvenile to adult.
A growing body of evidence shows that microplastic pollution is ubiquitous in bivalve mollusks globally and is of particular concern due to its potential impact on human health. However, ...non-standardized sampling, processing, and analytical techniques increased the difficulty of direct comparisons among existing studies. Based on 61 peer-reviewed papers, we summarized the current knowledge of microplastics in bivalve mollusks globally and provided an in-depth analysis of factors affecting the outcome of microplastic data, with the main focus on the effects of different species and methodologies. We found no significant differences in microplastic abundance among genera from the same family but significant differences among bivalve families, indicating habitats play an important role in microplastic ingestion by bivalve mollusks. This also provided foundational knowledge for using epifaunal and infaunal bivalves to monitor microplastic pollution in water and sediment, respectively. Recommendations for microplastic monitoring protocol in bivalve mollusks were proposed according to the results of this review, covering (i) a sample size of at least 50 bivalves in the study area, (ii) the use of 10 % KOH as the digestion solution, and (iii) the pore size of a filter membrane of < 5 µm. Acknowledging the need for a standard procedure, more efforts towards protocol standardization used in long-term and large-scale microplastic monitoring programs in bivalve mollusks are needed.
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•Global microplastic pollution status in bivalve mollusks is summarized.•Factors affecting the microplastic abundance in bivalves are analyzed.•Methodological heterogeneity in reported microplastic abundance is noted.•A protocol standardization is needed for microplastic monitoring in bivalves.
To meet the high-accuracy position/force control requirements of dual-arm robots for handling a target object, a control algorithm for dual-arm robots based on the modified sliding mode impedance ...controller MSMIC(tanh) is proposed. First, the combinative kinematics equation of the dual-arm robots and the unified dynamics model combining the manipulated object is established. Second, according to the impedance control motion model for the object, the desired joint angular accelerations of the manipulators are obtained, and the sliding mode controller based on the hyperbolic tangent function as the switch function is introduced to design the coordinated control strategy for dual-arm robots. The stability and convergence of the designed controller are proved according to the Lyapunov function theory. Finally, the operation tasks of the coordinated transport the target object for dual-arm robots are carried out in the simulated experiment environment. Simulation results show that the proposed control scheme can stably output the required internal force and achieve a high-precision trajectory tracking effect while reducing the periodic torque and joint chattering amplitude generated in the conventional sliding mode control algorithm.
Loop Closure Detection (LCD) is an important technique to improve the accuracy of Simultaneous Localization and Mapping (SLAM). In this paper, we propose an LCD algorithm based on binary ...classification for feature matching between similar images with deep learning, which greatly improves the accuracy of LCD algorithm. Meanwhile, a novel lightweight convolutional neural network (CNN) is proposed and applied to the target detection task of key frames. On this basis, the key frames are binary classified according to their labels. Finally, similar frames are input into the improved lightweight feature matching network based on Transformer to judge whether the current position is loop closure. The experimental results show that, compared with the traditional method, LFM-LCD has higher accuracy and recall rate in the LCD task of indoor SLAM while ensuring the number of parameters and calculation amount. The research in this paper provides a new direction for LCD of robotic SLAM, which will be further improved with the development of deep learning.
Long noncoding RNAs (lncRNAs) are a class of functional non-coding transcripts that are longer than 200 nt and regulate gene expression via diverse mechanisms in eukaryotes. In fact, they have ...emerged as critical epigenetic and transcriptional regulators of autophagy in mammals in response to various stressors. Autophagy not only plays a crucial role in maintaining cellular homeostasis, but it is also essential to immunity, targets intracellular pathogens for degradation, modulates inflammation, and participates in adaptive immune responses. However, the expression profile of lncRNA and its role in regulating autophagy in macrophages have been poorly defined. Here, we used transcriptomic and bioinformatics to analysis LncRNA expression profile during autophagy and functional studies to evaluate the function of the metastasis-associated lung adenocarcinoma transcript-1 (Malat1) lncRNA in macrophages. A total of 1112 putative lncRNAs (240 novel lncRNAs) were identified, including 831 large intergenic, 129 intronic, and 152 anti-sense lncRNA, of which 59 differentially expressed transcripts exhibited a greater than 1.5-fold change under different conditions. The interaction of Malat1 lncRNA with microRNA (mir)-23-3p and lysosomal-associated membrane protein 1 (Lamp1) was found, Malat1 releases inhibition of Lamp1 expression in macrophages through competitive adsorption of mir-23-3p. The results of this study provide a better understanding of lncRNA function in macrophages and a basis for further investigation into the roles and mechanisms of ncRNA in immunology, particularly the functions of Malat1 and mir-23-3p in the pathogenesis of macrophages.
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•Plastic additives of OPFRs, BPs and TBBPA derivates can be utilized by the gut cultures.•Gut microbiota modulates pollutants bioavailability via “first-pass metabolism” and ...“hepato-enteric circulation”.•Specific enzyme analysis confirmed the metabolic abilities of the gut microbiota.•Escherichia-Shigella, Citrobacter, and Anaerospora might be involved in the transformation.
The role of the gut microbiota in host physiology has been previously elucidated for some marine organisms, but little information is available on their metabolic activity involved in transformation of environmental pollutants. This study assessed the metabolic profiles of the gut microbial cultures from grouper (Epinephelus coioides), green mussel (Perna viridis) and giant tiger prawn (Penaeus monodon) and investigated their transformation mechanisms to typical plastic additives. Community-level physiological profiling analysis confirmed the utilization profiles of the microbial cultures including carbon sources of carbohydrates, amines, carboxylic acids, phenolic compounds, polymers and amino acids, and the plastic additives of organophosphate flame retardants, tetrabromobisphenol A derivates and bisphenols. Using in vitro incubation, triphenyl phosphate (TPHP) was found to be rapidly metabolized into diphenyl phosphate by the gut microbiota as a representative ester-containing plastic additive, whereas the transformation of BPA (a representative phenol) was relatively slower. Interestingly, all three kinds of microbial cultures efficiently transformed the hepatic metabolite of BPA (BPA-G) back to BPA, thereby increasing its bioavailability in the body. The specific enzyme analysis confirmed the ability of the gut microbiota to perform the metabolic reactions. The results of 16S rRNA sequencing and network analysis revealed that the genera Escherichia-Shigella, Citrobacter, and Anaerospora were functional microbes, and their collaboration with fermentative microbes played pivotal roles in the transformation of the plastic additives. The structure-specific transformations by the gut microbiota and their distinct bioavailability deserve more attention in the future.
Brominated flame retardants (BFRs) such as tetrabromobisphenol A (TBBPA) and hexabromocyclododecanes (HBCDs) are of ecological concern due to their ubiquitous presence and adverse effects. There is a ...paucity of data on environmental fate of such compounds in mangrove wetlands, which are unique ecosystems in coastal intertidal areas and act as natural sinks for many pollutants. In this study, mangrove plants and sediments were collected from an urban nature reserve in South China to investigate bioaccumulation and translocation of TBBPA and HBCDs. The mean (range) concentrations of TBBPA and ΣHBCD in roots, stems and leaves were 67 (<MDL-999), 174 (0.73–1105) and 20 (0.59–250) pg/g dry weight (dw), and 329 (15.6–2234), 766 (32.9–3255) and 298 (19.9–1520) pg/g dw, respectively. Tissue-specific accumulations were observed, varying with plant species and compounds. HBCD diastereoisomer patterns were similar for all plant species. γ-HBCD was the major diastereoisomer in roots, while α-HBCD dominated in stems and leaves. The predominance of α-HBCD in aboveground tissues may be ascribed to diastereoisomer-specific translocation, isomerization and/or metabolization in mangrove plants. Preferential enrichment of (−)-α-, (−)-β- and (+)-γ-HBCDs was found in all mangrove plant tissues, suggesting the enantioselectivity for HBCDs in mangrove plants. Translocation factors (log TF, root to stem) of HBCD diastereoisomers and log Kow were negatively correlated (p = 0.03), indicating passive translocation of HBCDs, driven by water movement during transpiration. Sediment-root bioaccumulation factors and log TFs (stem to leaf) both showed no obvious correlation with log Kow of HBCD diastereoisomers. These results reflected the complex behavior of HBCDs in mangrove plants, which have not been sufficiently captured in laboratory-based studies of plant contaminant accumulation.
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•TBBPA and HBCDs in natural mangrove plants were first reported.•TBBPA and HBCDs levels in Futian mangrove plants were relatively low.•Diastereo- and enantio-selective behaviors of HBCDs were found in mangrove plants.•Translocation of HBCDs from root to stem was negatively correlated with log Kow.•Foliar uptake could be an important pathway for SOCs to enter mangrove plants.
The Mask R-CNN-based object detection method is typically very time-consuming and laborious since it involves obtaining the required target object masks during training. Therefore, in order to ...automatically generate the image mask, we propose a GrabCut-based automated mask generation method for object detection. The proposed method consists of two stages. The first stage is based on GrabCut's interactive image segmentation method to generate the mask. The second stage is based on the object detection network of Mask R-CNN, which uses the mask from the previous stage together with the original input image and the associated label information for training. The Mask R-CNN model then automatically detects the relevant objects during testing. During experimentation with three objects from the Berkeley Instance Recognition Dataset, this method achieved a mean of average precision (mAP) value of over 95% for segmentation. The proposed method is simple and highly efficient in obtaining the mask of a segmented target object.
Microplastic pollution has become an increasingly important environmental issue worldwide in recent years because of its ubiquitous presence in different environmental media and its potential to ...affect the health of organisms and ecosystems. Aquaculture contributes significantly to the world's food production and nutritional supply, especially in developing countries. Widespread occurrence of microplastics in aquaculture systems has raised great concern regarding aquaculture production and food safety issues of aquaculture products. China is a world leader in aquaculture production, with freshwater aquaculture accounting for 59.1% of total aquaculture production of the world in 2020. Therefore, this review mainly focuses on recent research progress related to microplastic pollution in freshwater aquaculture systems in China. Results from the literature show that microplastics are present in freshwater aquaculture systems at abundances comparable to natural waterbodies in China. Microplastics can be ingested and remain in the body of aquaculture products. Exposure to microplastics can adversely affect the health of aquatic organisms and aquatic ecosystem functions. However, risks of microplastics in real world environment remain uncertain. Consumption of freshwater aquaculture products is not a major pathway for human exposure to microplastics. To provide scientific guidance for governmental decision-making and pollution control, future work should focus on progress in toxicological methodology and understanding the impacts of microplastics at community and ecosystem levels.
•Evidence on residential greenness and fetal growth in utero is scarce in China.•Residential greenness were beneficially associated with fetal growth in utero.•The associations were stronger in women ...exposed to lower levels of PM2.5.
Although studies have examined the association between residential greenness and birth weight, there is no evidence regarding the association between residential greenness and fetal growth in utero. We aimed to investigate the associations of residential greenness with both fetal growth in utero and birth weight.
A birth cohort (2014–2017) with 18,665 singleton pregnancies was established in Tongzhou Maternal and Child hospital of Beijing, China. Residential greenness was matched with maternal residential address and estimated from remote satellite data using normalized difference vegetation index with 200 m and 500 m buffers (NDVI-200 and NDVI-500). Fetal parameters including estimated fetal weight (EFW), abdominal circumference (AC), head circumference (HC) and femur length (FL) were assessed by ultrasound measurements during pregnancy. Fetal parameters were standardized as gestational-age- and gender-adjusted Z-score and undergrowth was defined as Z-score < −1.88. Birth weight Z-score, low birth weight (LBW) and small for gestational age (SGA) were assessed as birth outcomes. Generalized estimating equations with the autoregressive working correlation structure and generalized linear regression were used to examine the associations of residential greenness with quantitative and categorized outcomes.
We found an increase Z-score of EFW 0.054, 95% confidence interval (CI): 0.020–0.087, AC (0.045, 95%CI: 0.011–0.080) and HC (0.054, 95%CI: 0.020–0.089) associated with residential greenness above NDVI-500 median compared to less than and equal to NDVI-500 median. Stratified analyses indicated that the associations might be stronger in women exposed to lower levels of particles with aerodynamic diameters ≤2.5 µm. No associations were found in the analyses of NDVI-250 with fetal growth in utero. We didn’t observe significant associations of NDVI with birth weight Z-score, LBW and SGA.
This study identified a positive association of NDVI-500 and fetal growth in utero, but we didn’t observe its association with birth weight measures. Our results suggest that building sufficient green infrastructure might potentially promote early life health.
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