155 research outputs found
Hybrid-learning-based driver steering intention prediction using neuromuscular dynamics
The emerging automated driving technology poses a new challenge on driver-automation collaboration. In this study, oriented by human-machine mutual understanding, a driver steering intention prediction method is proposed to better understand human driver's expectation during driver-vehicle interaction. The steering intention is predicted based on a novel hybrid-learning-based time-series model with deep learning networks. Two different driving modes, namely, both hands and single right-hand driving modes, are studied. Different electromyography (EMG) signals from the upper limb muscles are collected and used for the steering intention prediction. The relationship between the neuromuscular dynamics and the steering torque is analyzed first. Then, the hybrid-learning-based model is developed to predict both the continuous and discrete steering intentions. The two intention prediction networks share the same temporal pattern exaction layer, which is built with the Bi-directional Recurrent Neural Network (RNN) and Long short-term memory (LSTM) cells. The model prediction performance is evaluated with a varied history and prediction horizon to exploit the model capability further. The experimental data are collected from 21 participants of varied ages and driving experience. The results show that the proposed method can achieve a prediction accuracy of around 95% steering under the two driving modes
Molecular Cloning of the Genes Encoding the PR55/Bβ/δ Regulatory Subunits for PP-2A and Analysis of Their Functions in Regulating Development of Goldfish, Carassius auratus
The protein phosphatase-2A (PP-2A), one of the major phosphatases in eukaryotes, is a heterotrimer, consisting of a scaffold A subunit, a catalytic C subunit and a regulatory B subunit. Previous studies have shown that besides regulating specific PP-2A activity, various B subunits encoded by more than 16 different genes, may have other functions. To explore the possible roles of the regulatory subunits of PP-2A in vertebrate development, we have cloned the PR55/B family regulatory subunits: β and δ, analyzed their tissue specific and developmental expression patterns in Goldfish ( Carassius auratus). Our results revealed that the full-length cDNA for PR55/Bβ consists of 1940 bp with an open reading frame of 1332 nucleotides coding for a deduced protein of 443 amino acids. The full length PR55/Bδ cDNA is 2163 bp containing an open reading frame of 1347 nucleotides encoding a deduced protein of 448 amino acids. The two isoforms of PR55/B display high levels of sequence identity with their counterparts in other species. The PR55/Bβ mRNA and protein are detected in brain and heart. In contrast, the PR55/Bδ is expressed in all 9 tissues examined at both mRNA and protein levels. During development of goldfish, the mRNAs for PR55/Bβ and PR55/Bδ show distinct patterns. At the protein level, PR55/Bδ is expressed at all developmental stages examined, suggesting its important role in regulating goldfish development. Expression of the PR55/Bδ anti-sense RNA leads to significant downregulation of PR55/Bδ proteins and caused severe abnormality in goldfish trunk and eye development. Together, our results suggested that PR55/Bδ plays an important role in governing normal trunk and eye formation during goldfish development
Microbial community regulation and performance enhancement in gas biofilters by interrupting bacterial communication
Abstract
Background
Controlling excess biomass accumulation and clogging is important for maintaining the performance of gas biofilters and reducing energy consumption. Interruption of bacterial communication (quorum quenching) can modulate gene expression and alter biofilm properties. However, whether the problem of excess biomass accumulation in gas biofilters can be addressed by interrupting bacterial communication remains unknown.
Results
In this study, parallel laboratory-scale gas biofilters were operated with Rhodococcus sp. BH4 (QQBF) and without Rhodococcus sp. BH4 (BF) to explore the effects of quorum quenching (QQ) bacteria on biomass accumulation and clogging. QQBF showed lower biomass accumulation (109 kg/m3) and superior operational stability (85–96%) than BF (170 kg/m3; 63–92%) at the end of the operation. Compared to BF, the QQBF biofilm had lower adhesion strength and decreased extracellular polymeric substance production, leading to easier detachment of biomass from filler surface into the leachate. Meanwhile, the relative abundance of quorum sensing (QS)-related species was found to decrease from 67 (BF) to 56% (QQBF). The QS function genes were also found a lower relative abundance in QQBF, compared with BF. Moreover, although both biofilters presented aromatic compounds removal performance, the keystone species in QQBF played an important role in maintaining biofilm stability, while the keystone species in BF exhibited great potential for biofilm formation. Finally, the possible influencing mechanism of Rhodococcus sp. BH4 on biofilm adhesion was demonstrated. Overall, the results of this study achieved excess biomass control while maintaining stable biofiltration performance (without interrupting operation) and greatly promoted the use of QQ technology in bioreactors.
Graphical Abstract
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Genomic and oncogenic preference of HBV integration in hepatocellular carcinoma
Hepatitis B virus (HBV) can integrate into the human genome, contributing to genomic instability and hepatocarcinogenesis. Here by conducting high-throughput viral integration detection and RNA sequencing, we identify 4,225 HBV integration events in tumour and adjacent non-tumour samples from 426 patients with HCC. We show that HBV is prone to integrate into rare fragile sites and functional genomic regions including CpG islands. We observe a distinct pattern in the preferential sites of HBV integration between tumour and non-tumour tissues. HBV insertional sites are significantly enriched in the proximity of telomeres in tumours. Recurrent HBV target genes are identified with few that overlap. The overall HBV integration frequency is much higher in tumour genomes of males than in females, with a significant enrichment of integration into chromosome 17. Furthermore, a cirrhosis-dependent HBV integration pattern is observed, affecting distinct targeted genes. Our data suggest that HBV integration has a high potential to drive oncogenic transformation
Subanesthetic Isoflurane Reduces Zymosan-Induced Inflammation in Murine Kupffer Cells by Inhibiting ROS-Activated p38 MAPK/NF- κ
Volatile anesthetic isoflurane (ISO) has immunomodulatory effects. The fungal component zymosan (ZY) induces inflammation through toll-like receptor 2 or dectin-1 signaling. We investigated the molecular actions of subanesthetic (0.7%) ISO against ZY-induced inflammatory activation in murine Kupffer cells (KCs), which are known as the resident macrophages within the liver. We observed that ISO reduced ZY-induced cyclooxygenase 2 upregulation and prostaglandin E2 release, as determined by western blot and radioimmunoassay, respectively. ISO also reduced the production of tumor necrosis factor-α, interleukin-1β, IL-6, high-mobility group box-1, macrophage inflammatory protein-1α, macrophage inflammatory protein-2, and monocyte chemoattractant protein-1 as assessed by enzyme-linked immunosorbent assays. ISO blocked the ZY-induced nuclear translocation and DNA-binding activity of nuclear factor- (NF)-κB p65. Moreover, ISO attenuated ZY-induced p38 mitogen-activated protein kinase (MAPK) activation partly by scavenging reactive oxygen species (ROS); the interregulation that ROS activated p38 MAPK followed by NF-κB activation was crucial for the ZY-induced inflammatory responses in KCs. An in vivo study by peritoneal injection of ZY into BALB/C mice confirmed the anti-inflammatory properties of 0.7% ISO against ZY in KCs. These results suggest that ISO ameliorates ZY-induced inflammatory responses in murine KCs by inhibiting the interconnected ROS/p38 MAPK/NF-κB signaling pathways
Whole-genome resequencing of wild and domestic sheep identifies genes associated with morphological and agronomic traits
Understanding the genetic changes underlying phenotypic variation in sheep (Ovis aries) may facilitate our efforts towards further improvement. Here, we report the deep resequencing of 248 sheep including the wild ancestor (O. orientalis), landraces, and improved breeds. We explored the sheep variome and selection signatures. We detected genomic regions harboring genes associated with distinct morphological and agronomic traits, which may be past and potential future targets of domestication, breeding, and selection. Furthermore, we found non-synonymous mutations in a set of plausible candidate genes and significant differences in their allele frequency distributions across breeds. We identified PDGFD as a likely causal gene for fat deposition in the tails of sheep through transcriptome, RT-PCR, qPCR, and Western blot analyses. Our results provide insights into the demographic history of sheep and a valuable genomic resource for future genetic studies and improved genome-assisted breeding of sheep and other domestic animals
STABILITY ANALYSIS OF DISC BRAKE SYSTEMS WITH UNCERTAINTY PARAMETERS
To suppress the brake noise of automotive disc brake systems,a stability analysis method of disc brake systems with random and fuzzy parameters was proposed. The proposed method was mainly based on the techniques of response surface methodology( RSM),complex eigenvalue analysis and reliability analysis. In the proposed method,the hybrid uncertainties existing in a disc brake system were described by random and fuzzy parameters,and the parameterized model of the damping ratio of unstable mode was established by RSM. The limit state function used to value system stable reliability was built up,and the reliability analysis was carried out for the uncertain brake system with random and fuzzy parameters. In order to explore the influence of system parameters on system stability,the parameter sensitivities were carried out by the global sensitivity analysis of Morris method. By introducing the proposed method for the stability analysis of a disc brake system with random and fuzzy parameters,the reliability and the parameter sensitivities were calculated. The numerical results show that the stability of this brake system can be improved by reducing the densities of back plates or by increasing the thicknesses of back plates
Revisiting the linkage between engineered ecosystem function and the microbial community: A review from ecological perspectives
Biological waste treatment technology is currently the world’s largest application process, and its functional achievement mainly relies on complex microbial communities. However, the microbial system in such engineered ecosystems has been considered a “black box.” Over the past decade, with the development of molecular biotechnology and next-generation sequencing technologies, the exploration of such “black boxes” has gradually deepened. In particular, the role of ecological forces in uncovering and regulating microbial communities has been largely recognized and has provided novel insights into the link between microbial communities and engineering objectives. However, the study of community ecology in engineered ecosystems is still in its early infancy and faces grand challenges in bridging engineering principles with microbial ecology theory. In this review, we discuss recent advances in the understanding of microbial community behavior in biological waste treatment systems, including biodiversity and its influencing factors, the role of neglected rare species, microbial interactions, and community assembly mechanisms. We emphasize the importance of these ecological perspectives in revealing and regulating microbial communities and functions, such as the enhancement of contaminant removal and operational stability in engineered ecosystems. In particular, cross-validation of the microbial community analysis results is necessary to yield valid real information to guide the improvement and stability of engineering ecosystem performance. Multi-omics approaches and synthetic community biology are preferred ways to link ecological theory and engineering objectives.</p
Identifying Reservoirs and Estimating Evaporation Losses in a Large Arid Inland Basin in Northwestern China
Reservoirs play a vital role in agricultural irrigation, food security, and ecological protection in arid and semi–arid areas where water resources are scarce. In the Tarim Basin (TB) in northwestern China, a large number of reservoirs have been built or are being built, resulting in significant evaporation losses. However, information about the distribution, area and evaporation rate of the reservoirs in TB is limited. To contribute, we present an inventory of reservoirs and calculate their monthly surface area and evaporation rate during the study period of 1990–2019, using the TerraClimate dataset, Google Earth Engine (GEE) platform, Landtrendr algorithm, Penman method, and Landsat images. The results suggest: (1) The inventory of 167 reservoirs in TB consists of 142 existing reservoirs (built before 1990), 5 new reservoirs (mountain reservoirs, built during 1990–2019), and 20 dried–up reservoirs (plain reservoirs that went extinct during 1990–2019). (2) The reservoir types in TB are mainly plain reservoirs with an altitude of less than 1500 m and an area of less than 10 km2, accounting for about 88% of the total number of reservoirs. (3) The surface area of the reservoirs increased at a significant rate (p < 0.05) of 12.45 km2/y from 401 km2 in 1990 to 766 km2 in 2019. (4) The evaporation rate of the reservoirs increased at a slight trend of 0.004 mm/d/a and varied from 2.57 mm/d in 1990 to 2.39 mm/d in 2019. Lastly, (5) The evaporation losses of reservoirs in TB significantly increased (p < 0.05) from 4.72 × 108 m3 to 4.92 × 108 m3 due to the significant increase in reservoir surface area (p < 0.05) and the slight increase in evaporation rate from 1990 to 2019. This study provides essentials of the reservoir inventory, surface area, and evaporation rate with considerable baseline inferences for TB that may be beneficial for long–term investigations and assist in local water resources decision support and sustainable management in arid regions
Gulo Acts as a de novo Marker for Pronephric Tubules in Xenopus laevis
Backgrounds/Aims: Vitamin C is an antioxidant and acts as a cofactor for several key enzymatic catalytic reactions in animals. Amphibians produce vitamin C in their kidneys, as opposed to mammals that produce vitamin C in their liver. Gulo serves as a crucial enzyme for vitamin C synthesis in mammals, but the characteristics and localization of its homologous genes during kidney development in Xenopus laevis, an amphibian, remains unknown. Methods: We aligned amino acid sequences of Gulo across different species by using bioinformatics methods and detected patterns of expression for Gulo during kidney development by using RT-PCR and in situ hybridization. Results: We identified a new site on the X. laevis genome, LOC495407. Sequence alignment analysis indicated this fragment is highly conserved and homologous to gulo genes in mammals. RT-PCR and in situ hybridization results reveal that X. laevis gulo is maternally expressed during the early stages of embryonic development, particularly, in the tubules of the pronephros from the middle tail-bud stage and onward in embryos. Conclusion: Gulo is a novel specific marker for pronephros tubules in X. laevis, and may be used as a potential marker for kidney development studies and disease diagnosis in mammals
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