83 research outputs found

    Feed types driven differentiation of microbial community and functionality in marine integrated multitrophic aquaculture system

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    Integrated multi trophic aquaculture (IMTA) improves the production of aquatic animals by promoting nutrient utilization through different tropical levels. Microorganisms play an important role in elements cycling, energy flow and farmed-species health. The aim of this study was to evaluate how feed types, fresh frozen fish diet (FFD) or formulated diet (FD), influence the microbial community diversity and functionality in both water and sediment in a marine IMTA system. Preferable water quality, higher animal yields and higher cost efficiency were achieved in the FD pond. Feed types changed the pond bacterial community distribution, especially in the rearing water. The FFD pond was dominated with Cyanobacteria in the water, which played an important role in nitrogen fixation through photosynthesis due to the high nitrogen input of the frozen fish diet. The high carbohydrate composition in the formulated diet triggered higher metabolic pathways related to carbon and lipid metabolism in the water of the FD pond. Sediment had significantly higher microbial diversity than the rearing water. In sediment, the dominating genus, Sulfurovum and Desulfobulbus, were found to be positively correlated by network analysis, which had similar functionality in sulfur transformation. The relatively higher rates of antibiotic biosynthesis in the FFD sediment might be related to the pathogenic bacteria introduced by the trash fish diet. The difference in microbial community composition and metabolic pathways may be associated with the different pathways for nutrient cycling and animal growth performance. The formulated diet was determined to be more ecologically and economically sustainable than the frozen fish diet for marine IMTA pond systems.</p

    Outbred genome sequencing and CRISPR/Cas9 gene editing in butterflies

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    Butterflies are exceptionally diverse but their potential as an experimental system has been limited by the difficulty of deciphering heterozygous genomes and a lack of genetic manipulation technology. Here we use a hybrid assembly approach to construct high-quality reference genomes for Papilio xuthus (contig and scaffold N50: 492 kb, 3.4 Mb) and Papilio machaon (contig and scaffold N50: 81 kb, 1.15 Mb), highly heterozygous species that differ in host plant affiliations, and adult and larval colour patterns. Integrating comparative genomics and analyses of gene expression yields multiple insights into butterfly evolution, including potential roles of specific genes in recent diversification. To functionally test gene function, we develop an efficient (up to 92.5%) CRISPR/Cas9 gene editing method that yields obvious phenotypes with three genes, Abdominal-B, ebony and frizzled. Our results provide valuable genomic and technological resources for butterflies and unlock their potential as a genetic model system

    A multimodal cell census and atlas of the mammalian primary motor cortex

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    ABSTRACT We report the generation of a multimodal cell census and atlas of the mammalian primary motor cortex (MOp or M1) as the initial product of the BRAIN Initiative Cell Census Network (BICCN). This was achieved by coordinated large-scale analyses of single-cell transcriptomes, chromatin accessibility, DNA methylomes, spatially resolved single-cell transcriptomes, morphological and electrophysiological properties, and cellular resolution input-output mapping, integrated through cross-modal computational analysis. Together, our results advance the collective knowledge and understanding of brain cell type organization: First, our study reveals a unified molecular genetic landscape of cortical cell types that congruently integrates their transcriptome, open chromatin and DNA methylation maps. Second, cross-species analysis achieves a unified taxonomy of transcriptomic types and their hierarchical organization that are conserved from mouse to marmoset and human. Third, cross-modal analysis provides compelling evidence for the epigenomic, transcriptomic, and gene regulatory basis of neuronal phenotypes such as their physiological and anatomical properties, demonstrating the biological validity and genomic underpinning of neuron types and subtypes. Fourth, in situ single-cell transcriptomics provides a spatially-resolved cell type atlas of the motor cortex. Fifth, integrated transcriptomic, epigenomic and anatomical analyses reveal the correspondence between neural circuits and transcriptomic cell types. We further present an extensive genetic toolset for targeting and fate mapping glutamatergic projection neuron types toward linking their developmental trajectory to their circuit function. Together, our results establish a unified and mechanistic framework of neuronal cell type organization that integrates multi-layered molecular genetic and spatial information with multi-faceted phenotypic properties

    Unsymmetrical Growth Synthesis of Nontraditional Dendrimers

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    Developing highly complex molecules is of great significance in science and technology. Here we present an unprecedented type of dendrimer assembled from linear ABB-type monomer. The construction of this nontraditional ramified architecture was facilely achieved through one simple convergent strategy established on the iridium-catalyzed cycloaddition of organic azides with internal 1-thioalkynes (IrAAC). By virtue of the unsymmetrically growing fashion in this process, diverse functional groups could be conveniently distributed on both of its exterior and interior layers. Syntheses of two dendrons from the cooperation of one linear alkyne motif with different azides were presented to demonstrate the efficiency and fidelity of this protocol. Post-modifications on their core or periphery were further conducted, resulting in diverse newly functionalized dendrimers with up to ~16.0 kDa molecular weight. The identity and purity of these unsymmetrical dendritic macromolecules were well confirmed by 1H NMR, MS and SEC analysis

    Dual-Cameras-Based Driver&rsquo;s Eye Gaze Tracking System with Non-Linear Gaze Point Refinement

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    The human eye gaze plays a vital role in monitoring people&rsquo;s attention, and various efforts have been made to improve in-vehicle driver gaze tracking systems. Most of them build the specific gaze estimation model by pre-annotated data training in an offline way. These systems usually tend to have poor generalization performance during the online gaze prediction, which is caused by the estimation bias between the training domain and the deployment domain, making the predicted gaze points shift from their correct location. To solve this problem, a novel driver&rsquo;s eye gaze tracking method with non-linear gaze point refinement is proposed in a monitoring system using two cameras, which eliminates the estimation bias and implicitly fine-tunes the gaze points. Supported by the two-stage gaze point clustering algorithm, the non-linear gaze point refinement method can gradually extract the representative gaze points of the forward and mirror gaze zone and establish the non-linear gaze point re-mapping relationship. In addition, the Unscented Kalman filter is utilized to track the driver&rsquo;s continuous status features. Experimental results show that the non-linear gaze point refinement method outperforms several previous gaze calibration and gaze mapping methods, and improves the gaze estimation accuracy even on the cross-subject evaluation. The system can be used for predicting the driver&rsquo;s attention

    Kinetic modeling of diesel hydrogenation on a NiMo/γ-Al2O3 catalyst in the RTS process

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    The high and low temperature dual reaction zone RTS (removing trace sulfur) technology is a novel hydrotreating process but lack of in-depth understanding of its kinetics. Three-lump and five-lump kinetic models were developed based on the diesel hydrogenation experimental data which were carried out in the RTS process under various operating conditions to predict the concentrations of ultra-level sulfur and aromatics in hydrotreated oil samples, respectively. Moreover, the inhibiting effect of the hydrogen sulfide (H2S) on the hydrodesulfurization rates of S-compounds has been studied by performing calculations with the actual adsorption concentration of H2S in the catalytic active center. The proposed models were able to reproduce the RTS process with good adjustment and accuracy, and relative deviations below 10.7 % at sulfur content below 10 ppm and polycyclic aromatics hydrocarbons content below 3 wt%. Therefore, these models can serve as an effective guide for diesel hydrotreatment, and the calculated results indicate that the optimal operating conditions in the 1st and 2nd reactors are 350 °C and 340 °C, respectively, at a constant pressure of 6.4 MPa and H2/oil volume ratio of 300 v/v

    Effects of changes on gut microbiota in children with acute Kawasaki disease

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    Background Kawasaki disease (KD) is an acute febrile illness of early childhood. The exact etiology of the disease remains unknown. At present, research on KD is mostly limited to susceptibility genes, infections, and immunity. However, research on the correlation between gut microbiota and KD is rare. Methods Children with a diagnosis of acute KD and children undergoing physical examination during the same period were included. At the time of admission, the subjects’ peripheral venous blood and feces were collected. Faecal samples were analyzed for bacterial taxonomic content via high-throughput sequencing. The abundance, diversity, composition, and characteristic differences of the gut microbiota in KD and healthy children were compared by alpha diversity, beta diversity, linear discriminant analysis and LDA effect size analysis. Blood samples were used for routine blood examination, biochemical analysis, and immunoglobulin quantitative detection. Results Compared with the control group, the community richness and structure of gut microbiota in the KD group was significantly reduced (Chao1 richness estimator, mean 215.85 in KD vs. mean 725.76 in control, p < 0.01; Shannon diversity index, mean 3.32 in KD vs. mean 5.69 in control, p < 0.05). LEfSe analysis identified two strains of bacteria significantly associated with KD: Bacteroidetes and Dorea. Bacteroidetes were enriched in healthy children (mean 0.16 in KD vs. mean 0.34 in control, p < 0.05). Dorea was also enriched in healthy children but rarely existed in children with KD (mean 0.002 in KD vs. mean 0.016 in control, p < 0.05). Compared with the control, IgA and IgG in the KD group decreased (IgA, median 0.68 g/L in KD vs. median 1.06 g/L in control, p < 0.001; IgG, median 6.67 g/L in KD vs. median 9.71 g/L in control, p < 0.001), and IgE and IgM levels were not significantly changed. Conclusions Dysbiosis of gut microbiota occurs in children with acute KD and may be related to the etiology or pathogenesis of KD. It is worth noting that for the first time, we found that Dorea, a hydrogen-producing bacterium, was significantly reduced in children with acute KD. Overall, our results provide a theoretical basis for the prevention or diagnosis of KD based on intestinal microecology

    Tryptophan Metabolism, Regulatory T Cells, and Inflammatory Bowel Disease: A Mini Review

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    Inflammatory bowel disease (IBD) is a chronic inflammatory disorder of the gastrointestinal tract resulting from the homeostasis imbalance of intestinal microenvironment, immune dysfunction, environmental and genetic factors, and so on. This disease is associated with multiple immune cells including regulatory T cells (Tregs). Tregs are a subset of T cells regulating the function of various immune cells to induce immune tolerance and maintain intestinal immune homeostasis. Tregs are correlated with the initiation and progression of IBD; therefore, strategies that affect the differentiation and function of Tregs may be promising for the prevention of IBD-associated pathology. It is worth noting that tryptophan (Trp) metabolism is effective in inducing the differentiation of Tregs through microbiota-mediated degradation and kynurenine pathway (KP), which is important for maintaining the function of Tregs. Interestingly, patients with IBD show Trp metabolism disorder in the pathological process, including changes in the concentrations of Trp and its metabolites and alteration in the activities of related catalytic enzymes. Thus, manipulation of Treg differentiation through Trp metabolism may provide a potential target for prevention of IBD. The purpose of this review is to highlight the relationship between Trp metabolism and Treg differentiation and the role of this interaction in the pathogenesis of IBD
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